Monitor Description

The hybrid vehicle control ECU assembly performs many diagnostic tests to verify proper operation of internal ECU systems. In one of these tests, the hybrid vehicle control ECU assembly checks the result of the ECM self-test. If the hybrid vehicle control ECU assembly detects a "Fail" from the ECM self-test, it will conclude that there is an internal malfunction in the ECM. The hybrid vehicle control ECU assembly will illuminate the MIL and store a DTC.