Operation CHARM: Car repair manuals for everyone.

Powertrain Diagnosis

CIRCUIT DESCRIPTION
The Engine Control Module (ECM) contains data which is essential to running the engine. The ECM continuously checks the integrity of this data.

CONDITIONS FOR RUNNING THE DTC
The ECM is powered up.

CONDITIONS FOR SETTING THE DTC
The ECM is unable to correctly read data from the flash memory.

ACTION TAKEN WHEN THE DTC SETS
^ The control module illuminates the Malfunction Indicator Lamp (MIL) when the diagnostic runs and fails.
^ The control module records the operating conditions at the time the diagnostic fails. The control module stores this information in the Freeze Frame/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.
^ Use a scan tool in order to clear the MIL and the DTC.

DIAGNOSTIC AIDS
Ensure the engine controls power relay was not removed while the ignition was ON. This Diagnostic Trouble Code (DTC) and several others will set if the switched B+ voltage is removed from the ECM while the ECM is powered up. Test for intermittent or poor connections on the switched B+ 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 and Poor Connections in Diagrams.

TEST

Steps 1-5: