Maintenance: Service and Repair

Lamp Reset Switch:

Federal Models
The Check Engine lamp will be illuminated when the ignition switch is in the On position with engine not operating. When engine is started, the Check Engine lamp should go off. If lamp remains on, either a service interval is indicated or a code has been stored by the Electronic Control Module (ECM) memory.

At mileage intervals of 50,000, 80,000 and 100,000 miles, the Check Engine lamp will be illuminated indicating required service and maintenance is to be performed. After performing the required service, the lamp may be turned off by resetting the cancel switch located behind the L.H. side of the instrument panel.

If a service code has been stored in the ECM memory, perform diagnosis and repair, then place ignition switch in Off position and clear codes stored in the ECM memory by disconnecting the battery ground cable for approximately 20 seconds.

California Models
The Check Engine lamp will be illuminated when the ignition switch is in the On position with engine not operating. When engine is started, the Check Engine lamp should go off. If lamp remains on, a code has been stored by the Electronic Control Module (ECM) memory. After diagnosis and repair, place ignition switch in Off position, then clear codes stored in the ECM memory by disconnecting the battery ground cable, for approximately 20 seconds.