DIC codes
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From: Milton FL
DIC codes
Man, got hit on way home with service engine soon, service traction control, & reduced engine power!! Pulled DIC codes and hope they point to a common ground fault. I got 1120 HC, 1221 HC, & C1278 HC. Any help much appreciated
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Here are the diagnostics to go with those codes. C1278 was probably caused by the other two so focus on them first. Make sure to check all related grounds and signal connections for corrosion.
DTC P1120 Throttle Position (TP) Sensor 1 Circuit
Refer to Cell 20: TP and APP Sensors for complete circuit details.
Circuit Description
The throttle position (TP) sensor is mounted on the throttle body assembly. The sensor is actually 2 individual TP sensors within one housing. Two separate signal, ground and 5 volt reference circuits are used in order to connect the TP sensor assembly and the throttle actuator control (TAC) module. The 2 sensors have opposite functionality. The TP sensor 1 signal voltage increases as the throttle opens, from below 1.0 volt at 0 percent throttle to above 3.5 volts at 100 percent throttle. The TP sensor 2 signal voltage decreases from around 3.8 volts at 0 percent throttle to below 1.0 volt at 100 percent throttle. Also observe that the signal circuit for TP Sensor 1 is pulled up to 5 volts and that the signal circuit for TP Sensor 2 is referenced to ground within the TAC module.
Conditions for Running the DTC
• DTCs P0606, P1517, P1518 are not set.
• The ignition switch is in the crank or run position.
• The ignition voltage greater than 5.23 volts.
Conditions for Setting the DTC
• TP sensor 1 voltage is less than 0.13 volts or greater than 4.87 volts.
• All of the above conditions met for less than 1 second.
Action Taken When the DTC Sets
• The PCM stores the DTC information into memory when the diagnostic runs and fails.
• The PCM illuminates the malfunction indicator lamp (MIL) when the diagnostic runs and fails.
• The PCM records the operating conditions at the time the diagnostic fails. The PCM stores this information in the Freeze Frame and/or Failure Records.
• The TAC system operates in reduced engine power mode. If certain TAC system DTCs are set at the same time, the TAC system may command the engine to shut down.
Conditions for Clearing the MIL/DTC
• The PCM turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
• A last test failed, or current DTC, clears when the diagnostic runs and does not fail.
• A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
• Use a scan tool in order to clear the MIL and the DTC.
Diagnostic Aids
Important
• Remove any debris from the PCM\TAC module connector surfaces before servicing the PCM\TAC module. Inspect the PCM\TAC module connector gaskets when diagnosing/replacing the modules. Ensure that the gaskets are installed correctly. The gaskets prevent contaminate intrusion into the PCM\TAC modules.
• For any test that requires probing the PCM or a component harness connector, use the Connector Test Adapter Kit J 35616-A . Using this kit prevents damage to the harness/component terminals. Refer to Using Connector Test Adapters in Wiring Systems.
• Inspect the TAC module connectors for signs of water intrusion. When this occurs, multiple DTCs should be set and no circuit or component conditions can be located.
• The APP sensor 1 and the TP sensor 1 5.0 volt reference circuits are internally connected within the TAC module.
• The APP sensor 2 and the TP sensor 2 5.0 volt reference circuits are internally connected within the TAC module.
• When the TAC module detects a condition within the TAC System, more than one TAC System related DTC may set. This is due to the many redundant tests run continuously on this system. Locating and repairing one individual condition may correct more than one DTC. Keep this in mind when reviewing captured DTC info.
• For an intermittent, refer to Symptoms .
Test Description
The numbers below refer to the step numbers on the Diagnostic Table.
3. Disconnect the Throttle Actuator connector before inserting fingers into the throttle bore. After you complete diagnosis, install the air inlet duct to the throttle body.
8. This step is testing for a short to voltage on the signal circuit.
12. This step verifies that 5.0 volts is available to the TP sensor 1 5.0 volt reference circuit.
13. This step is testing for a short to voltage on the 5.0 volt reference circuit.
14. The APP sensor 1 and the TP sensor 1 share a common 5 volt reference circuit. This step tests the APP sensor 1 for a short to B+.
36. When the TAC module detects a problem within the TAC System, more than one TAC System related DTC may set. This is due to the many redundant tests run continuously on this system. Locating and repairing one individual problem may correct more than one DTC. Keep this in mind when reviewing the captured DTC information.
DTC P1120 - Throttle Position (TP) Sensor 1 Circuit
Step
Action Values Yes No
1 Did you perform the Powertrain On-Board Diagnostic (OBD) System Check? -- Go to Step 2
Go to Powertrain On Board Diagnostic (OBD) System Check
2 Is DTC P1515, P1516, or P1518 also set? -- Go to Diagnostic Trouble Code (DTC) List/Type
Go to Step 3
3
1. Remove the air inlet duct from the Throttle Body Assembly.
Important
Disconnecting the throttle actuator motor connector causes additional DTCs to set.
2. Disconnect the Throttle Actuator harness connector. Refer to Front of Engine .
3. Close the throttle blade completely by hand while observing the TP sensor 1 voltage on the scan tool.
Is the voltage within the specified range? 0.13-0.67V Go to Step 4
Go to Step 7
4 Open the throttle blade to wide open throttle (WOT) by hand while observing the TP sensor 1 voltage on the scan tool.
Is the voltage within the specified range? 4.09-4.87V Go to Step 5
Go to Step 7
5 1. Reconnect the Throttle Actuator harness connector.
2. Turn OFF the ignition for 15 seconds.
3. Turn ON the ignition leaving the engine OFF.
4. Select the Diagnostic Trouble Code (DTC) option.
5. Move the harness and the related connectors while monitoring the DTC Information.
Did the harness movement cause this DTC to Fail this Ignition? -- Go to Step 22
Go to Step 6
6 1. Continue to monitor DTC Information with the scan tool.
2. Slowly depress the accelerator pedal to WOT and then slowly return it to a closed throttle.
Did this DTC Fail this Ignition? -- Go to Step 31
Go to Diagnostic Aids
7 1. Disconnect the TP sensor harness connector.
2. Measure the voltage at the TP sensor 1 signal circuit using the DMM connected to battery ground.
Is the voltage within the specified range? 3.94-6.06V Go to Step 12
Go to Step 8
8
1. Turn OFF the ignition.
2. Leave the TP sensor disconnected.
3. Disconnect the TAC Module connector containing the TP sensor circuits. Refer to Throttle Actuator Control (TAC) Module Replacement .
4. Turn ON the ignition leaving the engine OFF.
5. Measure the voltage from the TP sensor 1 signal circuit in the TP sensor harness connector to the battery ground using the DMM .
Is any voltage present? -- Go to Step 26
Go to Step 9
9 Test the harness for continuity of the TP sensor 1 signal circuit using the DMM. Refer to Testing for Continuity in Wiring Systems.
Is the resistance within the specified range? 0-2ohms Go to Step 10
Go to Step 27
10 Test the harness for continuity between the TP sensor 1 signal circuit and the battery ground using the DMM .
Does the DMM indicate continuity? -- Go to Step 28
Go to Step 11
11 Test the harness for continuity between the TP sensor 1 signal circuit, at the TAC harness connector, and all other circuits in both TAC module connectors using the DMM .
Does the DMM indicate continuity? -- Go to Step 30
Go to Step 33
12
Measure the voltage at the TP sensor 1 5.0 volt reference circuit to the battery ground using the DMM . Refer to Measuring Voltage in Wiring Systems.
Is the voltage within the specified range? 3.94-6.06V Go to Step 20
Go to Step 13
13
1. Turn OFF the ignition.
2. Leave the TP sensor disconnected.
3. Disconnect the TAC Module connector containing the TP sensor circuits. Refer to Throttle Actuator Control (TAC) Module Replacement .
4. Turn ON the ignition leaving the engine OFF.
5. Measure the voltage from the TP sensor 1 5.0 volt reference circuit in the TP sensor harness connector to the battery ground using the DMM .
Is any voltage present? -- Go to Step 23
Go to Step 14
14
1. Turn OFF the ignition.
2. Disconnect the APP sensor connector. Refer to Accelerator Pedal Position (APP) Sensor Replacement .
3. Disconnect the other TAC Module connector. Refer to Throttle Actuator Control (TAC) Module Replacement .
4. Turn ON the ignition leaving the engine OFF.
5. Measure the voltage from the APP sensor 1 5.0 volt reference circuit in the APP sensor harness connector to the battery ground using the DMM .
Is any voltage present? -- Go to Step 23
Go to Step 15
15 Test the harness for continuity of the TP sensor 1 5.0 volt reference circuit using the DMM . Refer to Testing for Continuity in Wiring Systems.
Is the resistance within the specified range? 0-2ohms Go to Step 16
Go to Step 24
16 Test the harness for continuity between the TP sensor 1 5.0 volt reference circuit and the battery ground using the DMM .
Does the DMM indicate continuity? -- Go to Step 25
Go to Step 17
17 Test the harness for continuity between the APP sensor 1 5 volt reference circuit and the battery ground using the DMM .
Does the DMM indicate continuity? -- Go to Step 25
Go to Step 18
18 Test the harness for continuity between the TP sensor 1 5.0 volt reference circuit, at the TAC harness connector, and all other circuits in both TAC module connectors using the DMM .
Does the DMM indicate continuity? -- Go to Step 30
Go to Step 19
19 Test the harness for continuity between the APP sensor 1 5 volt reference circuit, at the TAC harness connector, and all other circuits in both TAC module connectors using the DMM .
Does the DMM indicate continuity? -- Go to Step 30
Go to Step 33
20 1. Jumper the TP sensor 1 ground circuit to the TP sensor 1 signal circuit.
2. Monitor the TP sensor 1 voltage using a scan tool.
Is the voltage at the specified value? 0.0 Go to Step 31
Go to Step 21
21 1. Turn OFF the ignition.
2. Leave the TP sensor disconnected.
3. Disconnect the TAC Module connector containing the TP sensor circuits. Refer to Throttle Actuator Control (TAC) Module Replacement .
4. Test the harness for continuity of the TP sensor 1 ground circuit using the DMM .
Does the DMM indicate continuity? -- Go to Step 33
Go to Step 29
22 Repair the harness/connections as necessary. Refer to Wiring Repairs in Wiring Systems.
Is the action complete? -- Go to Step 35
--
23 Repair the short to voltage in the 5.0 volt reference circuit. Refer to Wiring Repairs in Wiring Systems.
Is the action complete? -- Go to Step 35
--
24 Repair the open/high resistance in the 5 volt reference circuit. Refer to Wiring Repairs in Wiring Systems.
Is the action complete? -- Go to Step 35
--
25 Repair the short to a ground in the 5.0 volt reference circuit. Refer to Wiring Repairs in Wiring Systems.
Is the action complete? -- Go to Step 35
--
26 Repair the signal circuit for a shorted to voltage. Refer to Wiring Repairs in Wiring Systems.
Is the action complete? -- Go to Step 35
--
27 Repair the open/high resistance in the signal circuit. Refer to Wiring Repairs in Wiring Systems.
Is the action complete? -- Go to Step 35
--
28 Repair the short to a ground in the signal circuit. Refer to Wiring Repairs in Wiring Systems.
Is the action complete? -- Go to Step 35
--
29 Repair the open/high resistance in the ground circuit. Refer to Wiring Repairs in Wiring Systems.
Is the action complete? -- Go to Step 35
--
30 Repair the circuits that are shorted together. Refer to Wiring Repairs in Wiring Systems.
Is the action complete? -- Go to Step 35
--
31 1. Inspect for a poor connection/terminal tension at the TP sensor harness connector. Refer to Testing for Intermittent and Poor Connections in Wiring Systems.
2. If you find a poor connection repair the condition as necessary. Refer to Repairing Connector Terminals in Wiring Systems.
Did you find and correct the condition? -- Go to Step 35
Go to Step 32
32 Replace the TP sensor. Refer to Throttle Position (TP) Sensor Replacement .
Is the action complete? -- Go to Step 35
--
33 1. Inspect for a poor connection/terminal tension at the TAC Module harness connector. Refer to Testing for Intermittent and Poor Connections in Wiring Systems.
2. If you find a poor connection repair the condition as necessary. Refer to Repairing Connector Terminals in Wiring Systems.
Did you find and correct the condition? -- Go to Step 35
Go to Step 34
34 Replace the TAC Module. Refer to Throttle Actuator Control (TAC) Module Replacement .
Is the action complete? -- Go to Step 35
--
35 1. Select the Diagnostic Trouble Code (DTC) option and the Clear DTC Information option using the scan tool.
2. Start the engine and idle at the normal operating temperature.
3. Select the Diagnostic Trouble Code (DTC) option and the Specific DTC option, then enter the DTC number using the scan tool.
4. Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text.
Does the scan tool indicate that this diagnostic ran and passed? -- Go to Step 36
Go to Step 2
36
Select the Capture Info option and the Review Info option using the scan tool.
Does the scan tool display any DTCs that you have not diagnosed? -- Go to the applicable DTC table System OK
DTC P1221 Throttle Position (TP) Sensor 1- 2 Correlation
Refer to Cell 20: TP and APP Sensors for complete circuit details.
Circuit Description
The throttle position (TP) sensor is mounted on the throttle body assembly . The sensor is actually 2 individual TP sensors within one housing. Two separate signal, ground and 5 volt reference circuits are used to connect the TP sensor assembly and the throttle actuator control (TAC) Module. The two sensors have opposite functionality. The TP sensor 1 signal voltage increases as the throttle opens, from below 1.0 volt at 0 percent throttle to above 3.5 volts at 100 percent throttle. The TP sensor 2 signal voltage decreases from around 3.8 volts at 0 percent throttle to below 1.0 volt at 100 percent throttle. Observe also that the signal circuit for TP sensor 1 is pulled up to 5 volts and that the signal circuit for TP Sensor 2 is pulled to ground within the TAC module.
Conditions for Running the DTC
• DTCs P0606, P1517, P1518 not set.
• Ignition switch in the crank or run position.
• Ignition voltage greater than 5.23 volts.
Conditions for Setting the DTC
• TP sensor 2 disagrees with TP sensor 1 by more than 7.5 percent.
• All above conditions met for less than 1 second.
Action Taken When the DTC Sets
• The PCM stores the DTC information into memory when the diagnostic runs and fails.
• The PCM illuminates the malfunction indicator lamp (MIL) when the diagnostic runs and fails.
• The PCM records the operating conditions at the time the diagnostic fails. The PCM stores this information in the Freeze Frame and/or Failure Records.
• If no other TAC System DTCs are set, the TAC System operates in Reduced Engine Power mode. If certain TAC System DTCs are set at the same time, the TAC System either defaults to a more tightly restricted mode of operation if the TAC determines that limited safe operation is possible, or the TAC commands the engine to shut down.
• The Driver Information Center displays a message.
Conditions for Clearing the MIL/DTC
• The PCM turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
• A last test failed, or current DTC, clears when the diagnostic runs and does not fail.
• A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
• Use a scan tool in order to clear the MIL and the DTC.
Diagnostic Aids
Important
• Remove any debris from the PCM\TAC module connector surfaces before servicing the PCM\TAC module. Inspect the PCM\TAC module connector gaskets when diagnosing/replacing the modules. Ensure that the gaskets are installed correctly. The gaskets prevent contaminate intrusion into the PCM\TAC modules.
• For any test that requires probing the PCM or a component harness connector, use the Connector Test Adapter Kit J 35616-A . Using this kit prevents damage to the harness/component terminals. Refer to Using Connector Test Adapters in Wiring Systems.
• Inspect the TAC module connectors for signs of water intrusion. When this occurs, multiple DTCs should be set and no circuit or component conditions can be located.
• The APP sensor 1 and the TP sensor 1 5.0 volt reference circuits are internally connected within the TAC module.
• The APP sensor 2 and the TP sensor 2 5.0 volt reference circuits are internally connected within the TAC module.
• When the TAC module detects a condition within the TAC System, more than one TAC System related DTC may set. This is due to the many redundant tests run continuously on this system. Locating and repairing one individual condition may correct more than one DTC. Keep this in mind when reviewing captured DTC info.
• For an intermittent, refer to Symptoms .
Test Description
The numbers below refer to the step numbers on the diagnostic table.
3. Disconnect the Throttle Actuator connector before inserting fingers into the throttle bore. Re-install the air inlet duct after repairs are completed.
5. This step determines what TP sensor circuit caused the DTC.
6. This step tests the TP sensor 1 5.0 volt reference circuit for high resistance. The TP sensor 2 voltage should display 5.0 volts when you jumper the two circuits together. Observe, the use of TP sensor 2 signal is only for diagnosing the TP sensor 1 5.0 volt reference circuit.
7. This step tests the TP sensor 1 signal and ground circuit.
8. This step verifies the TP sensor 1 signal circuit. The voltage should go to 0 volts when grounded. Inspect the signal circuit for high resistance if the voltage does not go to 0 volts.
9. This step tests the TP sensor 2 5.0 volt reference circuit for high resistance. The TP sensor 2 voltage should display 5.0 volts when you jumper the two circuits together.
10. This step tests for the TP sensor signal circuit. The TP sensor 2 voltage should display 5.0 volts.
31. When the TAC module detects a problem within the TAC System, more than one TAC System related DTC may set. This is due to the many redundant tests run continuously on this system. Locating and repairing one individual problem may correct more than one DTC. Keep this in mind when reviewing captured DTC info.
DTC P1221 - Throttle Position (TP) Sensors 1, 2 Performance
Step
Action Values Yes No
1 Did you perform the Powertrain On-Board Diagnostic (OBD) System Check? -- Go to Step 2
Go to Powertrain On Board Diagnostic (OBD) System Check
2 Important
If DTC P1120, P1220, P1515, P1516, and P1518 is also set, refer to applicable DTC for further diagnosis.
1. Turn ON the ignition leaving the engine OFF.
2. Monitor the TP sensors Disagree parameter using the scan tool.
Does the scan tool indicate NO? -- Go to Step 3
Go to Step 5
3
1. Remove the air inlet duct from the Throttle Body Assembly.
Important
Disconnecting the throttle actuator motor connector will cause additional DTCs to set.
2. Disconnect the Throttle Actuator harness connector.
3. Open the throttle blade to wide open throttle (WOT) by hand and then return it to closed throttle. Stop briefly at approximately 25, 50, 75 and 100 percent in each direction. Monitor the Throttle Sensors Disagree parameter at each stop.
Does the scan tool change from NO to YES while rotating the throttle blade? -- Go to Step 25
Go to Step 4
4 1. Reconnect the Throttle Actuator harness connector.
2. Turn OFF the ignition for 15 seconds.
3. Turn ON the ignition leaving the engine OFF.
4. Select the Diagnostic Trouble Code (DTC) option using the scan tool.
5. Move the harness and the related connectors while monitoring the DTC status.
Does the harness movement cause this DTC to set? -- Go to Step 14
Go to Diagnostic Aids
5
1. Turn OFF the ignition.
2. Remove the air inlet duct from the Throttle Body Assembly.
Important
Disconnecting the throttle actuator motor connector causes additional DTCs to set.
3. Disconnect the Throttle Actuator harness connector.
4. Turn ON the ignition leaving the engine OFF.
5. Close the throttle blade completely by hand while observing the TP sensor 1 voltage on the scan tool.
Is the voltage within the specified range? 0.13-0.67V Go to Step 9
Go to Step 6
6
1. Disconnect the TP sensor electrical connector.
2. Jumper the TP sensor 1 5 volt reference circuit to the TP sensor 2 signal circuit.
3. Monitor the TP sensor 2 voltage using a scan tool.
Is the TP sensor 2 voltage at the specified value? 5.0V Go to Step 7
Go to Step 12
7
1. Jumper the TP sensor 1 signal circuit to the TP sensor 1 ground circuit.
2. Monitor the TP sensor 1 voltage using a scan tool.
Is the TP sensor 1 voltage at the specified value? 0V Go to Step 24
Go to Step 8
8
1. Jumper the TP sensor 1 signal circuit to the battery ground circuit.
2. Monitor the TP sensor 1 voltage using a scan tool.
Is the TP sensor 1 voltage at the specified value? 0V Go to Step 16
Go to Step 14
9
1. Disconnect the TP sensor electrical connector.
2. Jumper the TP sensor 2 5 volt reference circuit to the TP sensor 2 signal circuit.
3. Monitor the TP sensor 2 voltage using a scan tool.
Is the TP sensor 2 voltage at the specified value? 5V Go to Step 11
Go to Step 10
10
1. Jumper the TP sensor 2 signal circuit to the TP sensor 1 5 volt reference circuit.
2. Monitor the TP sensor 2 voltage using a scan tool.
Is the TP sensor 2 voltage at the specified value? 5V Go to Step 18
Go to Step 20
11 1. Jumper the TP sensor 1 signal circuit to the TP sensor 2 ground circuit.
2. Monitor the TP sensor 1 voltage using a scan tool.
Is the TP sensor 1 voltage at the specified value? 0V Go to Step 24
Go to Step 22
12 1. Disconnect the TAC module harness connectors. Refer to Throttle Actuator Control (TAC) Module Replacement .
2. Test for continuity of the TP sensor 5 volt reference circuit between the TP sensor and the TAC module using the DMM .
Does the DMM indicate a continuity within the specified range? 0-2ohms Go to Step 13
Go to Step 27
13 Test for continuity at the TAC module harness between the TP sensor 1 5 volt reference circuit and all other circuits in both TAC module connectors using the DMM .
Does the DMM indicate continuity between any other circuit? -- Go to Step 26
Go to Step 28
14 1. Disconnect the TAC module harness connectors. Refer to Throttle Actuator Control (TAC) Module Replacement .
2. Test for continuity of the TP sensor 1 signal circuit between the TP sensor and the TAC module using the DMM .
Does the DMM indicate a continuity within the specified range? 0-2ohms Go to Step 15
Go to Step 27
15 Test for continuity at the TAC module harness between the TP sensor 1 signal circuit and all other circuits in both TAC module connectors using the DMM .
Does the DMM indicate continuity between any other circuit? -- Go to Step 26
Go to Step 28
16 1. Disconnect the TAC module harness connectors. Refer to Throttle Actuator Control (TAC) Module Replacement .
2. Test for continuity of the TP sensor 1 ground circuit between the TP sensor and the TAC module using the DMM .
Does the DMM indicate a continuity within the specified range? 0-2ohms Go to Step 17
Go to Step 27
17 Test for continuity at the TAC module harness between the TP sensor 1 ground circuit and all other circuits in both TAC module connectors using the DMM .
Does the DMM indicate continuity between any other circuit? -- Go to Step 26
Go to Step 28
18 1. Disconnect the TAC module harness connectors. Refer to Throttle Actuator Control (TAC) Module Replacement .
2. Test for continuity of the TP sensor 5 volt reference circuit between the TP sensor and the TAC module using the DMM .
Does the DMM indicate a continuity within the specified range? 0-2ohms Go to Step 19
Go to Step 27
19 Test for continuity at the TAC module harness between the TP sensor 2 5 volt reference circuit and all other circuits in both TAC module connectors using the DMM .
Does the DMM indicate continuity between any other circuit? 0-2ohms Go to Step 26
Go to Step 28
20 1. Disconnect the TAC module harness connectors. Refer to Throttle Actuator Control (TAC) Module Replacement .
2. Test for continuity of the TP sensor 2 signal circuit between the TP sensor and the TAC module using the DMM .
Does the DMM indicate a continuity within the specified range? 0-2ohms Go to Step 21
Go to Step 27
21 Test for continuity at the TAC module harness between the TP sensor 1 signal circuit and all other circuits in both TAC module connectors using the DMM .
Does the DMM indicate continuity between any other circuit? -- Go to Step 26
Go to Step 28
22 1. Disconnect the TAC module harness connectors. Refer to Throttle Actuator Control (TAC) Module Replacement .
2. Test for continuity of the TP sensor 2 ground circuit between the TP sensor and the TAC module using the DMM .
Does the DMM indicate a continuity within the specified range? 0-2ohms Go to Step 23
Go to Step 27
23 Test for continuity at the TAC module harness connector between the TP sensor 2 ground circuit and all other circuits in both TAC module connectors using the DMM .
Does the DMM indicate continuity between any other circuit? -- Go to Step 26
Go to Step 28
24 1. Inspect for poor connections/terminal tension at the TP sensor connector. Refer to Testing for Intermittent and Poor Connections in Wiring Systems.
2. If you find a poor connection, repair the condition as necessary. Refer to Repairing Connector Terminals in Wiring Systems.
Did you find and correct the condition? -- Go to Step 30
Go to Step 25
25 Replace the TP sensor. Refer to Throttle Position (TP) Sensor Replacement .
Is the action complete? -- Go to Step 30
--
26 Repair the circuits that are shorted together. Refer to Wiring Repairs in Wiring Systems.
Is the action complete? -- Go to Step 30
--
27 Repair the circuit with the high resistance. Refer to Wiring Repairs in Wiring Systems.
Is the action complete? -- Go to Step 30
--
28 1. Inspect for poor connections/terminal tension at the TAC module connectors. Refer to Testing for Intermittent and Poor Connections in Wiring Systems.
2. If you find a poor connection, repair the condition as necessary. Refer to Repairing Connector Terminals in Wiring Systems.
Did you find and correct the condition? -- Go to Step 30
Go to Step 29
29 Replace the TAC Module. Refer to Throttle Actuator Control (TAC) Module Replacement .
Is the action complete? -- Go to Step 30
--
30 1. Select the Diagnostic Trouble Code (DTC) option and the Clear DTC Information option using the scan tool.
2. Start the engine and idle at the normal operating temperature.
3. Select the Diagnostic Trouble Code (DTC) option and the Specific DTC option, then enter the DTC number using the scan tool.
4. Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text, if applicable.
Does the scan tool indicate that this diagnostic ran and passed? -- Go to Step 31
Go to Step 2
31
Select the Capture Info option and the Review Info option using the scan tool.
Does the scan tool display any DTCs that you have not diagnosed? -- Go to the applicable DTC table System OK
Bill
DTC P1120 Throttle Position (TP) Sensor 1 Circuit
Refer to Cell 20: TP and APP Sensors for complete circuit details.
Circuit Description
The throttle position (TP) sensor is mounted on the throttle body assembly. The sensor is actually 2 individual TP sensors within one housing. Two separate signal, ground and 5 volt reference circuits are used in order to connect the TP sensor assembly and the throttle actuator control (TAC) module. The 2 sensors have opposite functionality. The TP sensor 1 signal voltage increases as the throttle opens, from below 1.0 volt at 0 percent throttle to above 3.5 volts at 100 percent throttle. The TP sensor 2 signal voltage decreases from around 3.8 volts at 0 percent throttle to below 1.0 volt at 100 percent throttle. Also observe that the signal circuit for TP Sensor 1 is pulled up to 5 volts and that the signal circuit for TP Sensor 2 is referenced to ground within the TAC module.
Conditions for Running the DTC
• DTCs P0606, P1517, P1518 are not set.
• The ignition switch is in the crank or run position.
• The ignition voltage greater than 5.23 volts.
Conditions for Setting the DTC
• TP sensor 1 voltage is less than 0.13 volts or greater than 4.87 volts.
• All of the above conditions met for less than 1 second.
Action Taken When the DTC Sets
• The PCM stores the DTC information into memory when the diagnostic runs and fails.
• The PCM illuminates the malfunction indicator lamp (MIL) when the diagnostic runs and fails.
• The PCM records the operating conditions at the time the diagnostic fails. The PCM stores this information in the Freeze Frame and/or Failure Records.
• The TAC system operates in reduced engine power mode. If certain TAC system DTCs are set at the same time, the TAC system may command the engine to shut down.
Conditions for Clearing the MIL/DTC
• The PCM turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
• A last test failed, or current DTC, clears when the diagnostic runs and does not fail.
• A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
• Use a scan tool in order to clear the MIL and the DTC.
Diagnostic Aids
Important
• Remove any debris from the PCM\TAC module connector surfaces before servicing the PCM\TAC module. Inspect the PCM\TAC module connector gaskets when diagnosing/replacing the modules. Ensure that the gaskets are installed correctly. The gaskets prevent contaminate intrusion into the PCM\TAC modules.
• For any test that requires probing the PCM or a component harness connector, use the Connector Test Adapter Kit J 35616-A . Using this kit prevents damage to the harness/component terminals. Refer to Using Connector Test Adapters in Wiring Systems.
• Inspect the TAC module connectors for signs of water intrusion. When this occurs, multiple DTCs should be set and no circuit or component conditions can be located.
• The APP sensor 1 and the TP sensor 1 5.0 volt reference circuits are internally connected within the TAC module.
• The APP sensor 2 and the TP sensor 2 5.0 volt reference circuits are internally connected within the TAC module.
• When the TAC module detects a condition within the TAC System, more than one TAC System related DTC may set. This is due to the many redundant tests run continuously on this system. Locating and repairing one individual condition may correct more than one DTC. Keep this in mind when reviewing captured DTC info.
• For an intermittent, refer to Symptoms .
Test Description
The numbers below refer to the step numbers on the Diagnostic Table.
3. Disconnect the Throttle Actuator connector before inserting fingers into the throttle bore. After you complete diagnosis, install the air inlet duct to the throttle body.
8. This step is testing for a short to voltage on the signal circuit.
12. This step verifies that 5.0 volts is available to the TP sensor 1 5.0 volt reference circuit.
13. This step is testing for a short to voltage on the 5.0 volt reference circuit.
14. The APP sensor 1 and the TP sensor 1 share a common 5 volt reference circuit. This step tests the APP sensor 1 for a short to B+.
36. When the TAC module detects a problem within the TAC System, more than one TAC System related DTC may set. This is due to the many redundant tests run continuously on this system. Locating and repairing one individual problem may correct more than one DTC. Keep this in mind when reviewing the captured DTC information.
DTC P1120 - Throttle Position (TP) Sensor 1 Circuit
Step
Action Values Yes No
1 Did you perform the Powertrain On-Board Diagnostic (OBD) System Check? -- Go to Step 2
Go to Powertrain On Board Diagnostic (OBD) System Check
2 Is DTC P1515, P1516, or P1518 also set? -- Go to Diagnostic Trouble Code (DTC) List/Type
Go to Step 3
3
1. Remove the air inlet duct from the Throttle Body Assembly.
Important
Disconnecting the throttle actuator motor connector causes additional DTCs to set.
2. Disconnect the Throttle Actuator harness connector. Refer to Front of Engine .
3. Close the throttle blade completely by hand while observing the TP sensor 1 voltage on the scan tool.
Is the voltage within the specified range? 0.13-0.67V Go to Step 4
Go to Step 7
4 Open the throttle blade to wide open throttle (WOT) by hand while observing the TP sensor 1 voltage on the scan tool.
Is the voltage within the specified range? 4.09-4.87V Go to Step 5
Go to Step 7
5 1. Reconnect the Throttle Actuator harness connector.
2. Turn OFF the ignition for 15 seconds.
3. Turn ON the ignition leaving the engine OFF.
4. Select the Diagnostic Trouble Code (DTC) option.
5. Move the harness and the related connectors while monitoring the DTC Information.
Did the harness movement cause this DTC to Fail this Ignition? -- Go to Step 22
Go to Step 6
6 1. Continue to monitor DTC Information with the scan tool.
2. Slowly depress the accelerator pedal to WOT and then slowly return it to a closed throttle.
Did this DTC Fail this Ignition? -- Go to Step 31
Go to Diagnostic Aids
7 1. Disconnect the TP sensor harness connector.
2. Measure the voltage at the TP sensor 1 signal circuit using the DMM connected to battery ground.
Is the voltage within the specified range? 3.94-6.06V Go to Step 12
Go to Step 8
8
1. Turn OFF the ignition.
2. Leave the TP sensor disconnected.
3. Disconnect the TAC Module connector containing the TP sensor circuits. Refer to Throttle Actuator Control (TAC) Module Replacement .
4. Turn ON the ignition leaving the engine OFF.
5. Measure the voltage from the TP sensor 1 signal circuit in the TP sensor harness connector to the battery ground using the DMM .
Is any voltage present? -- Go to Step 26
Go to Step 9
9 Test the harness for continuity of the TP sensor 1 signal circuit using the DMM. Refer to Testing for Continuity in Wiring Systems.
Is the resistance within the specified range? 0-2ohms Go to Step 10
Go to Step 27
10 Test the harness for continuity between the TP sensor 1 signal circuit and the battery ground using the DMM .
Does the DMM indicate continuity? -- Go to Step 28
Go to Step 11
11 Test the harness for continuity between the TP sensor 1 signal circuit, at the TAC harness connector, and all other circuits in both TAC module connectors using the DMM .
Does the DMM indicate continuity? -- Go to Step 30
Go to Step 33
12
Measure the voltage at the TP sensor 1 5.0 volt reference circuit to the battery ground using the DMM . Refer to Measuring Voltage in Wiring Systems.
Is the voltage within the specified range? 3.94-6.06V Go to Step 20
Go to Step 13
13
1. Turn OFF the ignition.
2. Leave the TP sensor disconnected.
3. Disconnect the TAC Module connector containing the TP sensor circuits. Refer to Throttle Actuator Control (TAC) Module Replacement .
4. Turn ON the ignition leaving the engine OFF.
5. Measure the voltage from the TP sensor 1 5.0 volt reference circuit in the TP sensor harness connector to the battery ground using the DMM .
Is any voltage present? -- Go to Step 23
Go to Step 14
14
1. Turn OFF the ignition.
2. Disconnect the APP sensor connector. Refer to Accelerator Pedal Position (APP) Sensor Replacement .
3. Disconnect the other TAC Module connector. Refer to Throttle Actuator Control (TAC) Module Replacement .
4. Turn ON the ignition leaving the engine OFF.
5. Measure the voltage from the APP sensor 1 5.0 volt reference circuit in the APP sensor harness connector to the battery ground using the DMM .
Is any voltage present? -- Go to Step 23
Go to Step 15
15 Test the harness for continuity of the TP sensor 1 5.0 volt reference circuit using the DMM . Refer to Testing for Continuity in Wiring Systems.
Is the resistance within the specified range? 0-2ohms Go to Step 16
Go to Step 24
16 Test the harness for continuity between the TP sensor 1 5.0 volt reference circuit and the battery ground using the DMM .
Does the DMM indicate continuity? -- Go to Step 25
Go to Step 17
17 Test the harness for continuity between the APP sensor 1 5 volt reference circuit and the battery ground using the DMM .
Does the DMM indicate continuity? -- Go to Step 25
Go to Step 18
18 Test the harness for continuity between the TP sensor 1 5.0 volt reference circuit, at the TAC harness connector, and all other circuits in both TAC module connectors using the DMM .
Does the DMM indicate continuity? -- Go to Step 30
Go to Step 19
19 Test the harness for continuity between the APP sensor 1 5 volt reference circuit, at the TAC harness connector, and all other circuits in both TAC module connectors using the DMM .
Does the DMM indicate continuity? -- Go to Step 30
Go to Step 33
20 1. Jumper the TP sensor 1 ground circuit to the TP sensor 1 signal circuit.
2. Monitor the TP sensor 1 voltage using a scan tool.
Is the voltage at the specified value? 0.0 Go to Step 31
Go to Step 21
21 1. Turn OFF the ignition.
2. Leave the TP sensor disconnected.
3. Disconnect the TAC Module connector containing the TP sensor circuits. Refer to Throttle Actuator Control (TAC) Module Replacement .
4. Test the harness for continuity of the TP sensor 1 ground circuit using the DMM .
Does the DMM indicate continuity? -- Go to Step 33
Go to Step 29
22 Repair the harness/connections as necessary. Refer to Wiring Repairs in Wiring Systems.
Is the action complete? -- Go to Step 35
--
23 Repair the short to voltage in the 5.0 volt reference circuit. Refer to Wiring Repairs in Wiring Systems.
Is the action complete? -- Go to Step 35
--
24 Repair the open/high resistance in the 5 volt reference circuit. Refer to Wiring Repairs in Wiring Systems.
Is the action complete? -- Go to Step 35
--
25 Repair the short to a ground in the 5.0 volt reference circuit. Refer to Wiring Repairs in Wiring Systems.
Is the action complete? -- Go to Step 35
--
26 Repair the signal circuit for a shorted to voltage. Refer to Wiring Repairs in Wiring Systems.
Is the action complete? -- Go to Step 35
--
27 Repair the open/high resistance in the signal circuit. Refer to Wiring Repairs in Wiring Systems.
Is the action complete? -- Go to Step 35
--
28 Repair the short to a ground in the signal circuit. Refer to Wiring Repairs in Wiring Systems.
Is the action complete? -- Go to Step 35
--
29 Repair the open/high resistance in the ground circuit. Refer to Wiring Repairs in Wiring Systems.
Is the action complete? -- Go to Step 35
--
30 Repair the circuits that are shorted together. Refer to Wiring Repairs in Wiring Systems.
Is the action complete? -- Go to Step 35
--
31 1. Inspect for a poor connection/terminal tension at the TP sensor harness connector. Refer to Testing for Intermittent and Poor Connections in Wiring Systems.
2. If you find a poor connection repair the condition as necessary. Refer to Repairing Connector Terminals in Wiring Systems.
Did you find and correct the condition? -- Go to Step 35
Go to Step 32
32 Replace the TP sensor. Refer to Throttle Position (TP) Sensor Replacement .
Is the action complete? -- Go to Step 35
--
33 1. Inspect for a poor connection/terminal tension at the TAC Module harness connector. Refer to Testing for Intermittent and Poor Connections in Wiring Systems.
2. If you find a poor connection repair the condition as necessary. Refer to Repairing Connector Terminals in Wiring Systems.
Did you find and correct the condition? -- Go to Step 35
Go to Step 34
34 Replace the TAC Module. Refer to Throttle Actuator Control (TAC) Module Replacement .
Is the action complete? -- Go to Step 35
--
35 1. Select the Diagnostic Trouble Code (DTC) option and the Clear DTC Information option using the scan tool.
2. Start the engine and idle at the normal operating temperature.
3. Select the Diagnostic Trouble Code (DTC) option and the Specific DTC option, then enter the DTC number using the scan tool.
4. Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text.
Does the scan tool indicate that this diagnostic ran and passed? -- Go to Step 36
Go to Step 2
36
Select the Capture Info option and the Review Info option using the scan tool.
Does the scan tool display any DTCs that you have not diagnosed? -- Go to the applicable DTC table System OK
DTC P1221 Throttle Position (TP) Sensor 1- 2 Correlation
Refer to Cell 20: TP and APP Sensors for complete circuit details.
Circuit Description
The throttle position (TP) sensor is mounted on the throttle body assembly . The sensor is actually 2 individual TP sensors within one housing. Two separate signal, ground and 5 volt reference circuits are used to connect the TP sensor assembly and the throttle actuator control (TAC) Module. The two sensors have opposite functionality. The TP sensor 1 signal voltage increases as the throttle opens, from below 1.0 volt at 0 percent throttle to above 3.5 volts at 100 percent throttle. The TP sensor 2 signal voltage decreases from around 3.8 volts at 0 percent throttle to below 1.0 volt at 100 percent throttle. Observe also that the signal circuit for TP sensor 1 is pulled up to 5 volts and that the signal circuit for TP Sensor 2 is pulled to ground within the TAC module.
Conditions for Running the DTC
• DTCs P0606, P1517, P1518 not set.
• Ignition switch in the crank or run position.
• Ignition voltage greater than 5.23 volts.
Conditions for Setting the DTC
• TP sensor 2 disagrees with TP sensor 1 by more than 7.5 percent.
• All above conditions met for less than 1 second.
Action Taken When the DTC Sets
• The PCM stores the DTC information into memory when the diagnostic runs and fails.
• The PCM illuminates the malfunction indicator lamp (MIL) when the diagnostic runs and fails.
• The PCM records the operating conditions at the time the diagnostic fails. The PCM stores this information in the Freeze Frame and/or Failure Records.
• If no other TAC System DTCs are set, the TAC System operates in Reduced Engine Power mode. If certain TAC System DTCs are set at the same time, the TAC System either defaults to a more tightly restricted mode of operation if the TAC determines that limited safe operation is possible, or the TAC commands the engine to shut down.
• The Driver Information Center displays a message.
Conditions for Clearing the MIL/DTC
• The PCM turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
• A last test failed, or current DTC, clears when the diagnostic runs and does not fail.
• A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
• Use a scan tool in order to clear the MIL and the DTC.
Diagnostic Aids
Important
• Remove any debris from the PCM\TAC module connector surfaces before servicing the PCM\TAC module. Inspect the PCM\TAC module connector gaskets when diagnosing/replacing the modules. Ensure that the gaskets are installed correctly. The gaskets prevent contaminate intrusion into the PCM\TAC modules.
• For any test that requires probing the PCM or a component harness connector, use the Connector Test Adapter Kit J 35616-A . Using this kit prevents damage to the harness/component terminals. Refer to Using Connector Test Adapters in Wiring Systems.
• Inspect the TAC module connectors for signs of water intrusion. When this occurs, multiple DTCs should be set and no circuit or component conditions can be located.
• The APP sensor 1 and the TP sensor 1 5.0 volt reference circuits are internally connected within the TAC module.
• The APP sensor 2 and the TP sensor 2 5.0 volt reference circuits are internally connected within the TAC module.
• When the TAC module detects a condition within the TAC System, more than one TAC System related DTC may set. This is due to the many redundant tests run continuously on this system. Locating and repairing one individual condition may correct more than one DTC. Keep this in mind when reviewing captured DTC info.
• For an intermittent, refer to Symptoms .
Test Description
The numbers below refer to the step numbers on the diagnostic table.
3. Disconnect the Throttle Actuator connector before inserting fingers into the throttle bore. Re-install the air inlet duct after repairs are completed.
5. This step determines what TP sensor circuit caused the DTC.
6. This step tests the TP sensor 1 5.0 volt reference circuit for high resistance. The TP sensor 2 voltage should display 5.0 volts when you jumper the two circuits together. Observe, the use of TP sensor 2 signal is only for diagnosing the TP sensor 1 5.0 volt reference circuit.
7. This step tests the TP sensor 1 signal and ground circuit.
8. This step verifies the TP sensor 1 signal circuit. The voltage should go to 0 volts when grounded. Inspect the signal circuit for high resistance if the voltage does not go to 0 volts.
9. This step tests the TP sensor 2 5.0 volt reference circuit for high resistance. The TP sensor 2 voltage should display 5.0 volts when you jumper the two circuits together.
10. This step tests for the TP sensor signal circuit. The TP sensor 2 voltage should display 5.0 volts.
31. When the TAC module detects a problem within the TAC System, more than one TAC System related DTC may set. This is due to the many redundant tests run continuously on this system. Locating and repairing one individual problem may correct more than one DTC. Keep this in mind when reviewing captured DTC info.
DTC P1221 - Throttle Position (TP) Sensors 1, 2 Performance
Step
Action Values Yes No
1 Did you perform the Powertrain On-Board Diagnostic (OBD) System Check? -- Go to Step 2
Go to Powertrain On Board Diagnostic (OBD) System Check
2 Important
If DTC P1120, P1220, P1515, P1516, and P1518 is also set, refer to applicable DTC for further diagnosis.
1. Turn ON the ignition leaving the engine OFF.
2. Monitor the TP sensors Disagree parameter using the scan tool.
Does the scan tool indicate NO? -- Go to Step 3
Go to Step 5
3
1. Remove the air inlet duct from the Throttle Body Assembly.
Important
Disconnecting the throttle actuator motor connector will cause additional DTCs to set.
2. Disconnect the Throttle Actuator harness connector.
3. Open the throttle blade to wide open throttle (WOT) by hand and then return it to closed throttle. Stop briefly at approximately 25, 50, 75 and 100 percent in each direction. Monitor the Throttle Sensors Disagree parameter at each stop.
Does the scan tool change from NO to YES while rotating the throttle blade? -- Go to Step 25
Go to Step 4
4 1. Reconnect the Throttle Actuator harness connector.
2. Turn OFF the ignition for 15 seconds.
3. Turn ON the ignition leaving the engine OFF.
4. Select the Diagnostic Trouble Code (DTC) option using the scan tool.
5. Move the harness and the related connectors while monitoring the DTC status.
Does the harness movement cause this DTC to set? -- Go to Step 14
Go to Diagnostic Aids
5
1. Turn OFF the ignition.
2. Remove the air inlet duct from the Throttle Body Assembly.
Important
Disconnecting the throttle actuator motor connector causes additional DTCs to set.
3. Disconnect the Throttle Actuator harness connector.
4. Turn ON the ignition leaving the engine OFF.
5. Close the throttle blade completely by hand while observing the TP sensor 1 voltage on the scan tool.
Is the voltage within the specified range? 0.13-0.67V Go to Step 9
Go to Step 6
6
1. Disconnect the TP sensor electrical connector.
2. Jumper the TP sensor 1 5 volt reference circuit to the TP sensor 2 signal circuit.
3. Monitor the TP sensor 2 voltage using a scan tool.
Is the TP sensor 2 voltage at the specified value? 5.0V Go to Step 7
Go to Step 12
7
1. Jumper the TP sensor 1 signal circuit to the TP sensor 1 ground circuit.
2. Monitor the TP sensor 1 voltage using a scan tool.
Is the TP sensor 1 voltage at the specified value? 0V Go to Step 24
Go to Step 8
8
1. Jumper the TP sensor 1 signal circuit to the battery ground circuit.
2. Monitor the TP sensor 1 voltage using a scan tool.
Is the TP sensor 1 voltage at the specified value? 0V Go to Step 16
Go to Step 14
9
1. Disconnect the TP sensor electrical connector.
2. Jumper the TP sensor 2 5 volt reference circuit to the TP sensor 2 signal circuit.
3. Monitor the TP sensor 2 voltage using a scan tool.
Is the TP sensor 2 voltage at the specified value? 5V Go to Step 11
Go to Step 10
10
1. Jumper the TP sensor 2 signal circuit to the TP sensor 1 5 volt reference circuit.
2. Monitor the TP sensor 2 voltage using a scan tool.
Is the TP sensor 2 voltage at the specified value? 5V Go to Step 18
Go to Step 20
11 1. Jumper the TP sensor 1 signal circuit to the TP sensor 2 ground circuit.
2. Monitor the TP sensor 1 voltage using a scan tool.
Is the TP sensor 1 voltage at the specified value? 0V Go to Step 24
Go to Step 22
12 1. Disconnect the TAC module harness connectors. Refer to Throttle Actuator Control (TAC) Module Replacement .
2. Test for continuity of the TP sensor 5 volt reference circuit between the TP sensor and the TAC module using the DMM .
Does the DMM indicate a continuity within the specified range? 0-2ohms Go to Step 13
Go to Step 27
13 Test for continuity at the TAC module harness between the TP sensor 1 5 volt reference circuit and all other circuits in both TAC module connectors using the DMM .
Does the DMM indicate continuity between any other circuit? -- Go to Step 26
Go to Step 28
14 1. Disconnect the TAC module harness connectors. Refer to Throttle Actuator Control (TAC) Module Replacement .
2. Test for continuity of the TP sensor 1 signal circuit between the TP sensor and the TAC module using the DMM .
Does the DMM indicate a continuity within the specified range? 0-2ohms Go to Step 15
Go to Step 27
15 Test for continuity at the TAC module harness between the TP sensor 1 signal circuit and all other circuits in both TAC module connectors using the DMM .
Does the DMM indicate continuity between any other circuit? -- Go to Step 26
Go to Step 28
16 1. Disconnect the TAC module harness connectors. Refer to Throttle Actuator Control (TAC) Module Replacement .
2. Test for continuity of the TP sensor 1 ground circuit between the TP sensor and the TAC module using the DMM .
Does the DMM indicate a continuity within the specified range? 0-2ohms Go to Step 17
Go to Step 27
17 Test for continuity at the TAC module harness between the TP sensor 1 ground circuit and all other circuits in both TAC module connectors using the DMM .
Does the DMM indicate continuity between any other circuit? -- Go to Step 26
Go to Step 28
18 1. Disconnect the TAC module harness connectors. Refer to Throttle Actuator Control (TAC) Module Replacement .
2. Test for continuity of the TP sensor 5 volt reference circuit between the TP sensor and the TAC module using the DMM .
Does the DMM indicate a continuity within the specified range? 0-2ohms Go to Step 19
Go to Step 27
19 Test for continuity at the TAC module harness between the TP sensor 2 5 volt reference circuit and all other circuits in both TAC module connectors using the DMM .
Does the DMM indicate continuity between any other circuit? 0-2ohms Go to Step 26
Go to Step 28
20 1. Disconnect the TAC module harness connectors. Refer to Throttle Actuator Control (TAC) Module Replacement .
2. Test for continuity of the TP sensor 2 signal circuit between the TP sensor and the TAC module using the DMM .
Does the DMM indicate a continuity within the specified range? 0-2ohms Go to Step 21
Go to Step 27
21 Test for continuity at the TAC module harness between the TP sensor 1 signal circuit and all other circuits in both TAC module connectors using the DMM .
Does the DMM indicate continuity between any other circuit? -- Go to Step 26
Go to Step 28
22 1. Disconnect the TAC module harness connectors. Refer to Throttle Actuator Control (TAC) Module Replacement .
2. Test for continuity of the TP sensor 2 ground circuit between the TP sensor and the TAC module using the DMM .
Does the DMM indicate a continuity within the specified range? 0-2ohms Go to Step 23
Go to Step 27
23 Test for continuity at the TAC module harness connector between the TP sensor 2 ground circuit and all other circuits in both TAC module connectors using the DMM .
Does the DMM indicate continuity between any other circuit? -- Go to Step 26
Go to Step 28
24 1. Inspect for poor connections/terminal tension at the TP sensor connector. Refer to Testing for Intermittent and Poor Connections in Wiring Systems.
2. If you find a poor connection, repair the condition as necessary. Refer to Repairing Connector Terminals in Wiring Systems.
Did you find and correct the condition? -- Go to Step 30
Go to Step 25
25 Replace the TP sensor. Refer to Throttle Position (TP) Sensor Replacement .
Is the action complete? -- Go to Step 30
--
26 Repair the circuits that are shorted together. Refer to Wiring Repairs in Wiring Systems.
Is the action complete? -- Go to Step 30
--
27 Repair the circuit with the high resistance. Refer to Wiring Repairs in Wiring Systems.
Is the action complete? -- Go to Step 30
--
28 1. Inspect for poor connections/terminal tension at the TAC module connectors. Refer to Testing for Intermittent and Poor Connections in Wiring Systems.
2. If you find a poor connection, repair the condition as necessary. Refer to Repairing Connector Terminals in Wiring Systems.
Did you find and correct the condition? -- Go to Step 30
Go to Step 29
29 Replace the TAC Module. Refer to Throttle Actuator Control (TAC) Module Replacement .
Is the action complete? -- Go to Step 30
--
30 1. Select the Diagnostic Trouble Code (DTC) option and the Clear DTC Information option using the scan tool.
2. Start the engine and idle at the normal operating temperature.
3. Select the Diagnostic Trouble Code (DTC) option and the Specific DTC option, then enter the DTC number using the scan tool.
4. Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text, if applicable.
Does the scan tool indicate that this diagnostic ran and passed? -- Go to Step 31
Go to Step 2
31
Select the Capture Info option and the Review Info option using the scan tool.
Does the scan tool display any DTCs that you have not diagnosed? -- Go to the applicable DTC table System OK
Bill
