Engine Off Timer Monitor
The engine off timer is either implemented in a hardware circuit in the PCM or is obtained via a CAN message from the Body Control Module.
If the timer is implemented in the PCM, the following applies:
There are two parts to the test. The first part determines that the timer is incrementing during engine off. The test compares ECT prior to shutdown to ECT at key-on. The ECT has cooled down more than 30 deg F and the engine had warmed up to at least 160 deg F prior to shutdown, then an engine off soak has occurred. If the engine off timer indicates a value less than 30 sec, then the engine of timer is not functioning and a P2610 DTC is set.
The second part looks at the accuracy of the engine off timer itself. The timer in the satellite chip is allowed to count up for 5 minutes with the engine running and compared to a different clock in the main microprocessor. If the two timers differ by more than 15 sec (5%), a P2610 DTC is set.
If engine off time is obtained from the BCM, the following applies. There are multiple parts to the test:
The PCM expects to get a CAN message with the engine off time from BCM shortly after start. If the engine off time is not available because of a battery disconnect, the CAN message is set to FFFFh and a U0422 is set (Invalid Data Received from BCM).
If the CAN message with engine off time is not available, a P2610 DTC is set and a U0140 is set (Lost Communication with BCM).
As above, the next part determines that the timer is incrementing during engine off. The test compares ECT prior to shutdown to ECT at key-on. The ECT has cooled down more than 30 deg F and the engine had warmed up to at least 160 deg F prior to shutdown, then an engine off soak has occurred. If the engine off timer indicates a value less than 30 sec, then the engine of timer is not functioning and a P2610 DTC is set.
The last part looks at the accuracy of the engine off timer itself. The timer in the BCM (Global Real Time) is sampled for 5 minutes with the engine running and compared to the clock in the main microprocessor. If the two timers differ by more than 15 sec (5%), a P2610 DTC is set.
| DTCs | P2610 |
| Monitor Execution | Continuous within entry conditions |
| Monitor Sequence | None |
| Monitoring Duration | Immediately on startup or after 5 min |
| Engine off time < 30 seconds after inferred soak Engine off timer accuracy off by > 15 sec. Engine off time CAN message missing at startup |
| DTCs | P0642 - Sensor Reference Voltage "A" Circuit Low P0643 - Sensor Reference Voltage "A" Circuit High |
| Monitor Execution | Continuous |
| Monitor Sequence | None |
| Sensors OK | Not Applicable |
| Monitoring Duration | 5 sec to register a malfunction |
| Entry Condition | Minimum | Maximum |
| Ignition "ON" | NA | NA |
| P0642 Short to ground (signal voltage): < 4.75 V P0643 Short to battery plus (signal voltage): > 5.25 V |
| DTCs | P06A6 - Sensor Reference Voltage "A" Circuit Range/Performance P06A7 - Sensor Reference Voltage "B" Circuit Range/Performance P06A8 - Sensor Reference Voltage "C" Circuit Range/Performance |
| Monitor Execution | Continuous |
| Monitor Sequence | None |
| Sensors OK | Not Applicable |
| Monitoring Duration | 0.5 sec to register a malfunction |
| Entry Condition | Minimum | Maximum |
| Ignition "ON" | NA | NA |
| P0646, P0647, P06A8 (used for Bosch Tricore modules) Reference voltage: < 4.7 V or reference voltage: > 5.2 V |