The engine control module (ECM) contains data that is essential to running the engine. The ECM continuously checks the integrity of this data.
During the engine power down phase
The ECM determines that an internal data test did not pass.
• | The ECM illuminates the malfunction indicator lamp (MIL) on the first drive trip that the diagnostic runs and fails. |
• | The ECM attempts to record the operating conditions in the Freeze Frame, however, since this diagnostic trouble code (DTC) indicates that an internal ECM test did not pass, this information may not be useful for this specific DTC. |
• | The ECM turns OFF the MIL after three consecutive drive trips that the diagnostic runs and passes. |
• | A History DTC clears after forty consecutive warm-up cycles in which no failures are reported by this diagnostic or any other emission related diagnostic. |
• | The scan tool clears the MIL/DTC. |
This DTC may set if the battery is disconnected while the ECM is powered-up. This DTC and several others may set if the Switched B+ or the battery supply is removed from the ECM while the ECM is powered up. Test for intermittent or poor connections on the switched B+ and the battery supply circuits at the ECM. Also test the control circuit for the engine controls power relay for in intermittent open or high resistance and inspect the terminal contact at the relay. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.
Step | Action | Values | Yes | No | ||||
---|---|---|---|---|---|---|---|---|
1 | Did you perform the Powertrain On-Board Diagnostic (OBD) System Check? | -- | Go to Step 2 | |||||
2 |
Did this DTC set? | -- | Go to Step 3 | Go to Diagnostic Aids | ||||
3 |
Important:
Replace the ECM. Refer to Engine Control Module Replacement/Programming . Is the action complete? | -- | Go to Step 4 | -- | ||||
4 |
Does the scan tool indicate that the diagnostic Passed? | -- | Go to Step 5 | Go to Step 2 | ||||
5 | Does the scan tool display any additional undiagnosed DTCs? | -- | Go to the applicable DTC table | System OK |