Electronic EGR System Test

Incorporated within the Spark Control Computer is the EGR control.
1. With all engine temperature sensors operating properly, engine cold and ignition switch Off, connect a voltmeter to the gray wire on EGR solenoid and ground.
2. Start engine. Voltage reading obtained should be 1 volt. Voltage should remain constant at 1 volt until engine has reached operating temperature and EGR schedule has stopped. After engine has reached normal operating temperature and EGR schedule has stopped, solenoid will de-energize and voltmeter should indicate charging system voltage. If not, replace solenoid and repeat test.
3. If voltmeter indicates charging system voltage before the EGR schedule is complete, replace computer. If the engine is Hot started, EGR solenoid will be energized for the length of the time delay schedule only, and then de-energize.