Clearing Diagnostic Trouble Codes

Trouble Code Memory

When a trouble develops in the feedback system, the CHECK ENGINE light will illuminate and a trouble code will be stored in the ECM memory. If the fault is intermittent, the CHECK ENGINE light will be turned off after 10 seconds when the trouble ceases. However, the trouble code will be retained in the ECM memory until the battery voltage to the ECM is removed. Disconnecting the battery for at least 10 seconds will erase all stored trouble codes.