P2610

P2610-ECM/PCM INTERNAL ENGINE OFF TIMER PERFORMANCE







Theory of Operation

The PCM compares actual shutdown time to a calculated value, which is based on the amount the ECT should drop after a completely warmed up engine is shut down. If the difference is greater than a maximum value, a pending DTC will set.

- When Monitored:
After a complete engine warm up then ignition off time of greater than 1 hour with a minimum ECT drop of 10 C (50 C), with the engine running, the difference between ECT and AAT above 10 C (50 F) and battery voltage above 10 volts.

- Set Condition:
If the measured shutdown time is significantly greater than an expected shutdown time based on how much the ECT has dropped, a one trip failure sets. If this happens again after another warm up and 1 hour engine off period, the MIL will set.





Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Pre-Diagnostic Troubleshooting Procedure.

1. ENGINE COOLANT INSPECTION

NOTE: This DTC will set if the engine cools quicker than it should compared to engine off times. If a hot engine is washed with the ignition off, a pending DTC may set. If the vehicle is parked in a highly ventilated area or has a large fan blowing on it which might cause the engine to cool quicker than expected, a pending DTC may set.

WARNING: Do not remove or loosen the radiator cap with the system hot and under pressure. Serious burns from coolant can occur.

1. Turn the ignition off.
2. Allow the engine to cool enough to allow the pressure in the coolant system to drop enough to safely remove the radiator cap.
3. Check the coolant level and condition.

Is the engine coolant level filled to the proper level?

Yes

- Go To 2

No

- Add the appropriate type and amount of engine coolant and retest.
- Perform the PCM Verification Test. PCM Verification Test.

2. IGNITION OFF TIMER
1. Turn the ignition on.
2. With the scan tool under PCM/NGC Data Display, locate the Ignition Off Time value.
3. While monitoring a stop watch, turn the Ignition off for 10 minutes, watch the stop watch for those 10 minutes, and then turn the Ignition on.
4. With the scan tool under Data Functions, check the Ignition Off Time value again.

Does the Ignition Time Off value on the scan tool match the actual time you had the Ignition off on the stop watch?

Yes

- Refer to the CHECKING FOR AN INTERMITTENT DTC Diagnostic Procedure. Checking for an Intermittent DTC.

No

- Go To 3

3. CHECKING THE PCM POWER AND GROUND CIRCUITS
1. Perform the diagnostic procedure for CHECKING THE PCM POWER AND GROUND CIRCUITS. Checking the PCM Power and Ground Circuits.

Were any problems found?

Yes

- Repair the PCM power and ground circuit(s) as necessary and retest.
- Perform the PCM Verification Test. PCM Verification Test.

No

- Go To 4

4. POWERTRAIN CONTROL MODULE (PCM)
1. Verify that the PCM is operating at the latest software version available.
2. Search for any Technical Service Bulletins that may apply.

Were any problems found?

Yes

- Repair as necessary and retest.
- Perform the PCM Verification Test. PCM Verification Test.

No

- Replace and program the Powertrain Control Module (PCM).
- Perform the PCM Verification Test. PCM Verification Test.