check eng lite
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8th Gear
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check eng lite
Ok I have a 98 corvette the check eng light is on the code is 0113 I did replace the air flow censer but still its on.
I cant inspect the car and I'm going crazy dont know what to do next
any answers ?
THANKS
I cant inspect the car and I'm going crazy dont know what to do next
any answers ?
THANKS
Tech Contributor
Joined: Dec 2003
Posts: 19,384
Likes: 87
From: Horncastle Lincolnshire, England
2023 C5 of the Year Finalist - Unmodified
Not much to go on but here's the troubleshhoting guide if it offers any clues.
Document ID# 203496
1998 Chevrolet/Geo Corvette
DTC P0113 Intake Air Temperature (IAT) Sensor Circuit High Voltage
Circuit Description
The Intake Air Temperature (IAT) sensor contains a semiconductor device which changes the resistance based on the temperature (a thermistor). The IAT sensor is located in the air intake passage of the engine air induction system. The IAT sensor has a signal circuit and a ground circuit. The PCM applies 5.0 volts on the signal circuit to the sensor. The PCM monitors the changes in this voltage caused by changes in the resistance of the sensor in order to determine intake air temperature.
When the intake air is cold, the sensor (thermistor) resistance is high. The PCMs signal voltage is only pulled down a small amount through the sensor to a ground; therefore, the PCM senses a high signal voltage (low temperature). When the intake air is warm, the sensor resistance is low. The signal voltage is pulled down a greater amount; therefore, the PCM senses a low signal voltage (high temperature).
When the PCM senses a signal voltage higher than the normal operating range of the sensor, this DTC will set.
Conditions for Running the DTC
DTCs P0101, P0102, P0103, P0117, P0118, P0500, P0502, P0503 not set.
The engine coolant temperature is greater than 0°C (32°F).
The vehicle speed is less than 11.0 km/h (7.0 mph).
The Mass Air Flow is less than 15.0 g/s.
Conditions for Setting the DTC
The Intake Air Temperature is less than -35°C (-31°F).
All conditions met for 4.5 seconds.
Action Taken When the DTC Sets
The PCM illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
The PCM records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the PCM stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the PCM records the operating conditions at the time of the failure. The PCM writes the conditions to the Freeze Frame and updates the Failure Records.
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
The PCM terminals C1-24 and C2-24 are the Sensor Ground Jumper terminals. This DTC sets if the jumper is open or the connection between the jumper and the PCM is faulty. Inspect for proper termnal tension/connections at the PCM harness connector before replacing the PCM.
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 water intrusion into the PCM\TAC modules.
The following may cause an intermittent:
Mis-routed harness
Rubbed through wire insulation
Broken wire inside the insulation
If the engine has sat overnight, the engine coolant temperature and the intake air temperature values should display within a few degrees of each other. If the temperatures are not within 3°C (5°F), refer to Temperature vs Resistance .
If you determine that the DTC occurs intermittently, performing the P1111 diagnostic table may isolate the cause of the fault.
For an intermittent, refer to Symptoms .
Test Description
The numbers below refer to the step numbers on the diagnostic table.
This step determines if the malfunction is present. For any test that requires probing the PCM or component harness connectors, use the Connector Test Adapter Kit J 35616-A . Using this kit will prevent any damage to the harness connector terminals.
Using the Freeze Frame and/or Failure Records data may aid in locating an intermittent condition. If you cannot duplicate the DTC, the information included in the Freeze Frame and/or Failure Records data can help determine how many miles since the DTC set. The Fail Counter and Pass Counter can also help determine how many ignition cycles the diagnostic reported a pass and/or a fail. Operate the vehicle within the same freeze frame conditions (RPM, load, vehicle speed, temperature etc.) that you observed. This will isolate when the DTC failed. For any test that requires probing the PCM or component harness connectors, use the Connector Test Adapter Kit J 35616-A . Using this kit prevents any damage to the harness connector terminals.
An intake air temperature above 139°C (282°F) indicates that the PCM and IAT wiring are OK.
An intake air temperature above 139°C (282°F) indicates that the PCM and IAT signal circuit is OK.
Disconnecting the PCM allows using the DMM J 39200 in order to check continuity of the circuits. This aids in locating an open or a shorted circuit.
Disconnecting the PCM allows using the DMM J 39200 in order to check continuity of the circuits. This aids in locating an open or a shorted circuit.
The PCM terminals C1-24 and C2-24 are the Sensor Ground Jumper terminals. This DTC sets if the jumper is open or the connection between the jumper and the PCM is faulty. Inspect for proper terminal tension/ connections at the PCM harness connector before replacing the PCM.
Step
Action
Value(s)
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
Install a scan tool.
Turn ON the ignition leaving the engine OFF.
Monitor the IAT display on the Engine 1 Data List of the scan tool.
Is the IAT at the specified value?
-39°C (-38°F)
Go to Step 4
Go to Step 3
3
Turn ON the ignition leaving the engine OFF.
Review the Freeze Frame and/or Failure Records data for this DTC and observe the parameters.
Turn OFF the ignition for 15 seconds.
Start the engine.
Operate the vehicle within the conditions required for this diagnostic to run, and as close to the conditions recorded in the Freeze Frame/Failure Records as possible. Special operating conditions that you need to meet before the PCM will run this diagnostic, where applicable, are listed in Conditions for Running the DTC.
Select the Diagnostic Trouble Code (DTC) option, the Specific DTC option, then enter the DTC number using the scan tool.
Does the scan tool indicate that this diagnostic failed this ignition?
--
Go to Step 4
Go to Diagnostic Aids
4
Disconnect the IAT sensor electrical connector.
Jumper the IAT harness terminals together.
Observe the IAT parameter on the scan tool.
Is the IAT at the specified value?
140°C (284°F)
Go to Step 9
Go to Step 5
5
Jumper the IAT signal circuit to a known good ground.
Is the IAT at the specified value?
140°C (284°F)
Go to Step 8
Go to Step 6
6
Turn OFF the ignition.
Disconnect the PCM connector located on the same side as the manufacturer's logo. Refer to PCM/TAC Module Replacement .
Check the IAT sensor signal circuit for an open.
Is the IAT sensor signal circuit open?
--
Go to Step 7
Go to Step 12
7
Repair the IAT sensor signal circuit. Refer to Body and Accessories/Wiring Systems.
Is the action complete?
--
Go to Step 15
--
8
Turn OFF the ignition.
Disconnect both PCM connectors. Refer to PCM/TAC Module Replacement .
Check the IAT sensor ground circuit for an open between the IAT sensor and the PCM.
Did you find and correct the condition?
--
Go to Step 10
Go to Step 11
9
Replace the IAT sensor. Refer to Intake Air Temperature (IAT) Sensor Replacement .
Is the action complete?
--
Go to Step 15
--
10
Check the resistance between PCM connector terminals C1-24 and C2-24.
Is the resistance within the specified range?
0-5ohms
Go to Step 12
Go to Step 11
11
Repair the circuit with the high resistance. Refer to Body and Accessories/Wiring Systems.
Is the action complete?
--
Go to Step 15
--
12
Check for a short to voltage on the signal circuit.
Did you find and correct the condition?
--
Go to Step 15
Go to Step 13
13
Check for faulty connections at the PCM.
Did find and correct the condition?
--
Go to Step 15
Go to Step 14
14
Important:
Program the replacement PCM. Refer to PCM/TAC Module Replacement .
Replace the PCM.
Is the action complete?
--
Go to Step 15
--
15
Select the Diagnostic Trouble Code (DTC) option and the Clear DTC Information option using the scan tool.
Idle the engine at the normal operating temperature.
Select the Diagnostic Trouble Code (DTC) option and the Specific DTC option, then enter the DTC number using the scan tool.
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 test ran and passed?
--
Go to Step 16
Go to Step 2
16
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
Document ID# 203496
1998 Chevrolet/Geo Corvette
Document ID# 203496
1998 Chevrolet/Geo Corvette
DTC P0113 Intake Air Temperature (IAT) Sensor Circuit High Voltage
Circuit Description
The Intake Air Temperature (IAT) sensor contains a semiconductor device which changes the resistance based on the temperature (a thermistor). The IAT sensor is located in the air intake passage of the engine air induction system. The IAT sensor has a signal circuit and a ground circuit. The PCM applies 5.0 volts on the signal circuit to the sensor. The PCM monitors the changes in this voltage caused by changes in the resistance of the sensor in order to determine intake air temperature.
When the intake air is cold, the sensor (thermistor) resistance is high. The PCMs signal voltage is only pulled down a small amount through the sensor to a ground; therefore, the PCM senses a high signal voltage (low temperature). When the intake air is warm, the sensor resistance is low. The signal voltage is pulled down a greater amount; therefore, the PCM senses a low signal voltage (high temperature).
When the PCM senses a signal voltage higher than the normal operating range of the sensor, this DTC will set.
Conditions for Running the DTC
DTCs P0101, P0102, P0103, P0117, P0118, P0500, P0502, P0503 not set.
The engine coolant temperature is greater than 0°C (32°F).
The vehicle speed is less than 11.0 km/h (7.0 mph).
The Mass Air Flow is less than 15.0 g/s.
Conditions for Setting the DTC
The Intake Air Temperature is less than -35°C (-31°F).
All conditions met for 4.5 seconds.
Action Taken When the DTC Sets
The PCM illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
The PCM records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the PCM stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the PCM records the operating conditions at the time of the failure. The PCM writes the conditions to the Freeze Frame and updates the Failure Records.
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
The PCM terminals C1-24 and C2-24 are the Sensor Ground Jumper terminals. This DTC sets if the jumper is open or the connection between the jumper and the PCM is faulty. Inspect for proper termnal tension/connections at the PCM harness connector before replacing the PCM.
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 water intrusion into the PCM\TAC modules.
The following may cause an intermittent:
Mis-routed harness
Rubbed through wire insulation
Broken wire inside the insulation
If the engine has sat overnight, the engine coolant temperature and the intake air temperature values should display within a few degrees of each other. If the temperatures are not within 3°C (5°F), refer to Temperature vs Resistance .
If you determine that the DTC occurs intermittently, performing the P1111 diagnostic table may isolate the cause of the fault.
For an intermittent, refer to Symptoms .
Test Description
The numbers below refer to the step numbers on the diagnostic table.
This step determines if the malfunction is present. For any test that requires probing the PCM or component harness connectors, use the Connector Test Adapter Kit J 35616-A . Using this kit will prevent any damage to the harness connector terminals.
Using the Freeze Frame and/or Failure Records data may aid in locating an intermittent condition. If you cannot duplicate the DTC, the information included in the Freeze Frame and/or Failure Records data can help determine how many miles since the DTC set. The Fail Counter and Pass Counter can also help determine how many ignition cycles the diagnostic reported a pass and/or a fail. Operate the vehicle within the same freeze frame conditions (RPM, load, vehicle speed, temperature etc.) that you observed. This will isolate when the DTC failed. For any test that requires probing the PCM or component harness connectors, use the Connector Test Adapter Kit J 35616-A . Using this kit prevents any damage to the harness connector terminals.
An intake air temperature above 139°C (282°F) indicates that the PCM and IAT wiring are OK.
An intake air temperature above 139°C (282°F) indicates that the PCM and IAT signal circuit is OK.
Disconnecting the PCM allows using the DMM J 39200 in order to check continuity of the circuits. This aids in locating an open or a shorted circuit.
Disconnecting the PCM allows using the DMM J 39200 in order to check continuity of the circuits. This aids in locating an open or a shorted circuit.
The PCM terminals C1-24 and C2-24 are the Sensor Ground Jumper terminals. This DTC sets if the jumper is open or the connection between the jumper and the PCM is faulty. Inspect for proper terminal tension/ connections at the PCM harness connector before replacing the PCM.
Step
Action
Value(s)
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
Install a scan tool.
Turn ON the ignition leaving the engine OFF.
Monitor the IAT display on the Engine 1 Data List of the scan tool.
Is the IAT at the specified value?
-39°C (-38°F)
Go to Step 4
Go to Step 3
3
Turn ON the ignition leaving the engine OFF.
Review the Freeze Frame and/or Failure Records data for this DTC and observe the parameters.
Turn OFF the ignition for 15 seconds.
Start the engine.
Operate the vehicle within the conditions required for this diagnostic to run, and as close to the conditions recorded in the Freeze Frame/Failure Records as possible. Special operating conditions that you need to meet before the PCM will run this diagnostic, where applicable, are listed in Conditions for Running the DTC.
Select the Diagnostic Trouble Code (DTC) option, the Specific DTC option, then enter the DTC number using the scan tool.
Does the scan tool indicate that this diagnostic failed this ignition?
--
Go to Step 4
Go to Diagnostic Aids
4
Disconnect the IAT sensor electrical connector.
Jumper the IAT harness terminals together.
Observe the IAT parameter on the scan tool.
Is the IAT at the specified value?
140°C (284°F)
Go to Step 9
Go to Step 5
5
Jumper the IAT signal circuit to a known good ground.
Is the IAT at the specified value?
140°C (284°F)
Go to Step 8
Go to Step 6
6
Turn OFF the ignition.
Disconnect the PCM connector located on the same side as the manufacturer's logo. Refer to PCM/TAC Module Replacement .
Check the IAT sensor signal circuit for an open.
Is the IAT sensor signal circuit open?
--
Go to Step 7
Go to Step 12
7
Repair the IAT sensor signal circuit. Refer to Body and Accessories/Wiring Systems.
Is the action complete?
--
Go to Step 15
--
8
Turn OFF the ignition.
Disconnect both PCM connectors. Refer to PCM/TAC Module Replacement .
Check the IAT sensor ground circuit for an open between the IAT sensor and the PCM.
Did you find and correct the condition?
--
Go to Step 10
Go to Step 11
9
Replace the IAT sensor. Refer to Intake Air Temperature (IAT) Sensor Replacement .
Is the action complete?
--
Go to Step 15
--
10
Check the resistance between PCM connector terminals C1-24 and C2-24.
Is the resistance within the specified range?
0-5ohms
Go to Step 12
Go to Step 11
11
Repair the circuit with the high resistance. Refer to Body and Accessories/Wiring Systems.
Is the action complete?
--
Go to Step 15
--
12
Check for a short to voltage on the signal circuit.
Did you find and correct the condition?
--
Go to Step 15
Go to Step 13
13
Check for faulty connections at the PCM.
Did find and correct the condition?
--
Go to Step 15
Go to Step 14
14
Important:
Program the replacement PCM. Refer to PCM/TAC Module Replacement .
Replace the PCM.
Is the action complete?
--
Go to Step 15
--
15
Select the Diagnostic Trouble Code (DTC) option and the Clear DTC Information option using the scan tool.
Idle the engine at the normal operating temperature.
Select the Diagnostic Trouble Code (DTC) option and the Specific DTC option, then enter the DTC number using the scan tool.
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 test ran and passed?
--
Go to Step 16
Go to Step 2
16
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
Document ID# 203496
1998 Chevrolet/Geo Corvette
