secondary air has nothing to do with injector duration.engines need to run rich cold and lean out as they warm.secondary air runs only while the car is in open loop.on cold start,injector on time is longer but its strategy is figured out by coolant temp,front o2's,etc.
yes,i do agree,secondary air does help fire up the cats,but after that you can unbolt it and throw it on the ground[just like the choke in a carbuerator.once it is open you can toss it on the ground until your next cold start].
secondary air operation is figured by the front o2's[you can see it with a scanner by watching the short term fuel trims],by the time secondary air is clicked off,the cats are fired.
i also do agree,if you get a visual check.you will tank,as long as the person looking knows what to look for.
note;i haven't seen a screwed up motor yet from lack of secondary air.

 

The PCM monitors the following sensors and engine parameters to calculate engine output torque:

Air/Fuel ratio
Mass Air Flow (MAF)
Manifold Absolute Pressure (MAP)
Intake Air Temperature (IAT)
Spark Advance
Engine Speed
Engine Coolant Temperature (ECT)
A/C Clutch Status

P0118
Circuit Description
The engine coolant temperature (ECT) sensor is a variable resistor, that measures the temperature of the engine coolant. The powertrain control module (PCM) supplies 5 volts to the ECT signal circuit and a ground for the ECT low reference circuit. When the ECT is cold, the sensor resistance is high. When the ECT increases, the sensor resistance decreases. With high sensor resistance, the PCM detects a high voltage on the ECT signal circuit. With lower sensor resistance, the PCM detects a lower voltage on the ECT signal circuit. If the PCM detects an excessively low ECT signal voltage, which is a high temperature indication, DTC P0117 sets.

Conditions for Running the DTC
The engine has been running for more than 60 seconds.

Or

The engine run time is less than 60 seconds if the intake air temperature (IAT) is more than 0°C (32°F).

Conditions for Setting the DTC
The ECT sensor temperature is less than -39°C (-38°F) for 20 seconds.

Action Taken When the DTC Sets
The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.
Conditions for Clearing the MIL/DTC
The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
Clear the MIL and the DTC with a scan tool.
Diagnostic Aids
If a short to a separate 5-volt source occurs, this DTC may set. If this condition occurs, perform a continuity test to all other PCM circuits in order to diagnose the specific circuit.

After you start the engine, the engine coolant temperature (ECT) should rise steadily to approximately 90°C (194°F). The ECT should stabilize when the thermostat opens.

In order to evaluate the possibility of a skewed sensor, test the ECT sensor at various temperature levels. Refer to Temperature vs Resistance .

If a malfunction is not present, refer to DTC P1115 .

If you suspect an intermittent condition, refer to Intermittent Conditions .

Step
Action
Value
Yes
No

Schematic Reference: Engine Controls Schematics

1
Did you perform the Diagnostic System Check-Engine Controls?
--
Go to Step 2
Go to Diagnostic System Check - Engine Controls

2
Install a scan tool.
Turn ON the ignition, with the engine OFF.
Use a scan tool in order to observe the ECT sensor temperature.
Does the scan tool indicate that the ECT sensor temperature is less than the specified value?
-38°C (-36°F)
Go to Step 4
Go to Step 3

3
Observe the Freeze Frame/Failure Records for this DTC.
Turn OFF the ignition for 30 seconds.
Start the engine.
In order to operate the vehicle under similar conditions which set the DTC, use the following information:
The parameters listed in the Conditions for Running in the DTC
The data in the Freeze Frame/Failure Records
Does the DTC set?
--
Go to Step 4
Go to Diagnostic Aids

4
Turn OFF the ignition.
Disconnect the ECT sensor. Refer to Engine Coolant Temperature (ECT) Sensor Replacement .
Connect a 3-amp fused jumper wire between the signal circuit of the ECT sensor and of the low reference circuit. Refer to Using Fused Jumper Wires in Wiring Systems.
Turn ON the ignition, with the engine OFF.
With a scan tool, observe the ECT sensor temperature.
Does the scan tool indicate ECT sensor temperature more than the specified value?
138°C (280°F)
Go to Step 8
Go to Step 5

5
Turn OFF the ignition.
Connect a 3-amp fused jumper wire between the signal circuit of the ECT sensor and of a known good ground.
Turn ON the ignition, with the engine OFF.
With a scan tool, observe the ECT sensor temperature.
Does the scan tool indicate ECT sensor temperature greater than the specified value?
138°C (280°F)
Go to Step 7
Go to Step 6

6
Test the signal circuit of the ECT sensor for the following conditions:
A short to voltage
A high resistance
An open circuit
Repair the circuit as necessary. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Did you find and correct the condition?
--
Go to Step 12
Go to Step 7

7
Test the reference low circuit of the ECT sensor for a high resistance or for an open. Refer to Circuit Testing in Wiring Systems.
Repair the circuit as necessary. Refer to Connector Repairs in Wiring Systems.
Did you find and correct the condition?
--
Go to Step 12
Go to Step 9

8

Important
If a short to a separate voltage source occurs, this DTC may set and damage the ECT sensor. If this is found to be the condition, a continuity test to all other PCM circuits will be necessary to diagnose the specific fault.


Test the signal circuit of the ECT sensor for the following:
A short to voltage
A poor connection at the harness connector of the ECT sensor
Repair the connections as necessary. Refer to Connector Repairs in Wiring Systems.
Did you find and correct the condition?
--
Go to Step 12
Go to Step 10

9
Disconnect the PCM. Refer to Powertrain Control Module (PCM) Replacement .
Inspect for poor connections at the harness connector of the PCM.
Repair the connections as necessary, Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Did you find and correct the condition?
--
Go to Step 12
Go to Step 11

10
Replace the ECT sensor. Refer to Engine Coolant Temperature (ECT) Sensor Replacement .

Did you complete the replacement?
--
Go to Step 12
--

11
Replace the PCM. Refer to Powertrain Control Module (PCM) Replacement .

Did you complete the replacement?
--
Go to Step 12
--

12
Use a scan tool in order to clear the DTCs.
Turn OFF the ignition for 30 seconds.
Start the engine.
Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text.
Does the DTC run and pass?
--
Go to Step 13
Go to Step 2

13
Use a scan tool in order to observe the stored information in Capture Info.

Does the scan tool display any DTCs that you have not diagnosed?
--
Go to Diagnostic Trouble Code (DTC) List
System OK

 

DTC P1115
Circuit Description
The engine coolant temperature (ECT) sensor is a variable resistor, that measures the temperature of the engine coolant. The powertrain control module (PCM) supplies 5 volts to the ECT signal circuit and a ground for the ECT low reference circuit. When the ECT is cold, the sensor resistance is high. When the ECT increases, the sensor resistance decreases. With high sensor resistance, the PCM detects a high voltage on the ECT signal circuit. With lower sensor resistance, the PCM detects a lower voltage on the ECT signal circuit. If the PCM detects an excessively low ECT signal voltage, which is a high temperature indication, DTC P0117 sets.

Conditions for Running the DTC
Engine run time is more than 60 seconds.

Conditions for Setting the DTC
The PCM detects an ECT sensor temperature that is less than -35°C (-31°F).

The intermittent condition which exists for 1 second during a 20 second time period

Action Taken When the DTC Sets
The control module stores the DTC information into memory when the diagnostic runs and fails.
The malfunction indicator lamp (MIL) will not illuminate.
The control module records the operating conditions at the time the diagnostic fails. The control module stores this information in the Failure Records.
The driver information center, if equipped, may display a message.
Conditions for Clearing the DTC
A current DTC Last Test Failed clears when the diagnostic runs and passes.
A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other non-emission related diagnostic.
Clear the DTC with a scan tool.
Diagnostic Aids
An ECT sensor or a PCM which has any of the following intermittent conditions is unlikely:
A short
An open
A skewed sensor
An intermittent open or a short to voltage in the signal circuit of the ECT sensor, may result in a DTC P1115. If there is a high ECT voltage reading, additional circuit voltage codes of the sensor may be set. Refer to any non-intermittent DTCs that are set.
In order to evaluate the possibility of a skewed sensor, test the coolant sensor at various temperature levels. A skewed sensor may result in driveability concerns. Refer to Temperature vs Resistance .
Test Description
The number below refers to the step number on the diagnostic table.

If the DTC does not set, and there are not any driveability concerns which are associated with this DTC, the system is OK.

Step
Action
Yes
No

Schematic Reference: Engine Controls Schematics

1
Did you perform the Diagnostic System Check-Engine Controls?
Go to Step 2
Go to Diagnostic System Check - Engine Controls

2
Connect a scan tool.
Turn ON the ignition.
Start the engine.
Does the scan tool indicate that DTC P0118 also failed?
Go to DTC P0118
Go to Step 3

3
Turn ON the ignition, with the engine OFF.
With a scan tool observe the ECT, and move the sensor connector, and the PCM connector.
Does the scan tool indicate an abrupt change in value?
Go to Step 6
Go to Step 4

4
Turn ON the ignition, with the engine OFF.
With a scan tool, observe the ECT and move the wiring harness at the sensor, and at the PCM.
Does the scan tool indicate an abrupt change in value?
Go to Step 7
Go to Step 5

5
Observe the Freeze Frame/Failure Records for this DTC.
Turn OFF the ignition for 30 seconds.
Start the engine.
In order to operate the vehicle under the conditions which set the DTC, use the following information:
The data in the Freeze Frame/Failure Records
The parameters listed in the Conditions for Running in the DTC
Does the DTC set ?
Go to Diagnostic Aids
Go to Step 8

6
Repair the connector or the terminal as necessary. Refer to Circuit Testing and Connector Repairs in Wiring Systems.

Did you complete the repair?
--

7
Repair the harness or the wiring as necessary. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you complete the repair?
Go to Step 8
--

8
Use a scan tool in order to clear the DTCs.
Turn OFF the ignition for 30 seconds.
Start the engine.
Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text.
Does the DTC run, and pass?
Go to Step 9
Go to Step 2

9
With a scan tool, observe the stored information, Capture Info.

Does the scan tool display any DTCs that you have not diagnosed?
Go to Diagnostic Trouble Code (DTC) List
System OK

 

Secondary Air Injection (AIR) System Description


The Air Secondary Injection (AIR) pump on this vehicle is designed to lower the exhaust emission levels after engine start up.

The Powertrain Control Module (PCM) commands the AIR pump relay ON, by supplying a ground to the relay control circuit. This action energizes the AIR pump which forces air (oxygen) into the exhaust stream. The PCM also commands the AIR vacuum solenoid valve ON, by supplying a ground to the control circuit of the AIR solenoid. With the AIR solenoid activated engine vacuum is then applied to the AIR shut-off valve. Freash air from the AIR pump then enters into the exhaust stream. The air that is introduced into the exhaust system accelerates catalysts operation reducing exhaust emission levels. When the AIR system is inactive, the AIR shut-off valve and check valves prevent airflow in either direction.

The system includes the following components:

The AIR pump relay-- The AIR pump relay supplies high current to the AIR pump voltage supply circuit. The PCM commands the AIR relay ON by suppling a ground on the control circuit of the relay. This action closes the internal contacts of the AIR relay, energizing the AIR pump.
The AIR pump--The AIR pump supplies fresh air through the secondary air injection system into the exhaust stream. The PCM supplies a ground for the AIR pump relay. Battery voltage is then applied to the AIR pump. The inlet filter is the only serviceable part of the pump.
The AIR vacuum control solenoid--The AIR vacuum control solenoid controls the AIR shut-off valve. When the AIR system is enabled, the PCM supplies a ground to the solenoid. This enables the solenoid, allowing engine vacuum to be applied to the AIR shut-off valve.
The AIR shut-off valve--The AIR shut-off valve is vacuum operated. When the AIR system is enabled, engine vacuum is applied to the valve. The vacuum opens the valve and allows air from the AIR pump to flow to the check valves. When inactive the shut -off valve prevents airflow in either direction.
The check valves--The check valves prevent back flow of exhaust gases into the AIR system. A shut-off valve that has become inoperative, shows indications of exhaust gases in the outlet port, or heat damaged hoses may indicate a check valve failure.
The Pipes/Hoses--The pipes/hoses carry the air from the AIR pump to the exhaust stream. The pipes/hoses can be tested for leaks using a soapy water solution. With the AIR pump running, bubbles will form if a leak exists.
Results of Incorrect Operation
The PCM detects a system airflow problem by monitoring the heated oxygen senors (HO2S) and Short Term Fuel Trim (FT) values during normal open loop system operation. This is called a passive test. If the passive test indicates a pass, the PCM takes no further action. If the passive test fails or is inconclusive, the PCM diagnostic will proceed with an intrusive or active test. The PCM will command the AIR system ON, during normal closed loop operation and under normal operating conditions. This is called an active test. The active test will pass or fail based on the response from the HO2S. A lean HO2S response indicates that the AIR system is functioning normally. An increasing Short Term Fuel Trim value also indicates a normally functioning system. The AIR diagnostic consists of the combination of the passive and active test. It requires failure of the passive and active tests on two consecutive key cycles to illuminate the malfunction indicator lamp (MIL) and store a DTC. If the PCM detects that the HO2S and Short Term FT did not respond as expected on both of the engine banks DTC P0410 sets. If the PCM detects that the HO2S and Short Term FT did not respond as expected on only one of the engine banks DTC P1415 bank 1 or P1416 bank 2 sets.

If incorrect voltage is present on the vacuum control solenoid or the pump relay control circuits the device will not operate. This will be detected by the control module, and DTC P0412 for the solenoid or P0418 for the relay sets.

The following DTCs can set if a secondary air injection fault is detected:

P0410-- A system flow problem has been detected.
P0412--A vacuum control solenoid control circuit problem has been detected.
P0418-- A pump relay control circuit problem has been detected.
P1415--A Bank 1 flow problem has been detected.
P1416--A Bank 2 flow problem has been detected.

 

Holy smokes there 69 Whole lota reading there.

 

Engine Surges/Chuggles
Checks
Action

DEFINITION: Engine power variation during steady throttle or cruise. The vehicle appears to speed up and slow down, with no change in the accelerator pedal position.

Preliminary
Refer to Important Preliminary Checks Before Starting in Symptoms - Engine Controls .
Search for bulletins.
Inspect the PCM grounds for being clean, tight, and in the proper locations. Refer to Engine Controls Schematics .
Be sure the driver understands the operation of the transmission torque converter clutch (TCC) and A/C compressor operation as explained in the owner's manual. Inform the customer how the TCC and the A/C clutch operate.

Sensor/System
Test the heated oxygen sensors (HO2S). The HO2S should quickly respond to the different throttle positions. If the sensors are unresponsive, inspect the sensors for silicon or for other contaminates from the fuel or from the use of an improper room temperature vulcanizing (RTV) sealant. The sensors may have a white powdery coating which will cause a high but false signal voltage, indicating a rich exhaust indication. The powertrain control module (PCM) will then reduce the amount of fuel that is delivered to the engine, causing a severe driveability problem.
Inspect the mass air flow (MAF) sensor connections. Repair or replace the terminals. Refer to Repairing Connector Terminals in Wiring Systems.

Fuel System
Test for incorrect fuel pressure. Refer to Fuel System Diagnosis .
Test for a restricted fuel filter. Refer to Fuel System Diagnosis .
Test for a contaminated fuel condition. Refer to Alcohol/Contaminants-in-Fuel Diagnosis .
Ensure that each injector harness is connected to the correct injector and cylinder according to the firing order. The firing order is 1-8-7-2-6-5-4-3. Relocate the injector harnesses as necessary.
Test the fuel injectors. Refer to Fuel Injector Coil Test .
Test the items which can cause an engine to run rich, where the long term fuel trim is near -13 percent. For a rich condition, refer to DTC P0131 or P0151 and DTC P0132 or P0152 .
Test the items that can cause an engine to run lean, where the long term fuel trim is near 23 percent. For a lean condition, refer to DTC P0131 or P0151 and DTC P0132 or P0152 .

Ignition System
Wet down the secondary ignition system with water from a spray bottle. Wetting down the secondary ignition system may help locate damaged or deteriorated components. Look and listen for arcing or misfiring as you apply the water.
Test for proper ignition voltage output with spark tester J 26792 . Refer to Electronic Ignition (EI) System Diagnosis .
Remove the spark plugs and inspect for the following conditions:
Correct heat range
Wet plugs
Cracks
Wear
Improper gap
Burned electrodes
Heavy deposits
To properly inspect the spark plugs or to correct a problem, refer to the following procedures:
Ignition System Specifications
Spark Plug Inspection
Spark Plug Replacement
An improper spark plug gap causes a driveability condition. Gap the spark plugs using a wire gauge gap tool. Refer to Spark Plug Replacement .
Determine the cause of the fouling before replacing the spark plugs if the spark plugs are gas, coolant or oil fouled. Refer to DTC P0172 or P0175 for diagnosis of the rich condition. Refer to Spark Plug Inspection for diagnosis of coolant or oil fouled spark plugs.
Inspect for loose ignition coil grounds. Refer to Electronic Ignition (EI) System Diagnosis .

Engine Mechanical
Ensure that the engine coolant temperature is not above 130°C (266°F). This condition causes the PCM to operate in Engine Coolant Over Temperature-Fuel Disabled Mode. While in Engine Coolant Over Temperature-Fuel Disabled Mode, the PCM turns fuel OFF to 4 cylinders at a time in order to keep engine temperatures from reaching damaging levels. The system perceives Engine Coolant Over Temperature-Fuel Disabled Mode as a lack of power, a miss, or a rough idle. If the vehicle operates in Engine Coolant Over Temperature-Fuel Disabled Mode, refer to Engine Overheating in Engine Cooling for diagnosis.

Additional Checks
Inspect vacuum hoses for splits, for kinks, and for proper connections and routing as shown on Vehicle Emission Control Information label. Refer to Emission Hose Routing Diagram .
Test the transmission torque converter clutch (TCC) operation. A TCC applying too soon can cause the engine to spark knock. Refer to Torque Converter Diagnosis Procedure in Automatic Transmission - 4L60 E.
Test the A/C clutch for proper operation. Refer to Symptoms - HVAC Systems - Manual in HVAC Systems Manual, or Symptoms - HVAC Systems - Automatic in HVAC Systems Automatic