EGR System Test

The electronic EGR control is incorporated into the Spark Control Computer. Check to ensure that engine temperature switches are operating properly before proceeding with test.
1. With engine cold and ignition Off, connect one lead of suitable voltmeter to gray wire terminal on EGR solenoid. Connect second voltmeter lead to ground.
2. Start engine and check voltmeter reading. Reading should be less than one volt. Reading will remain at this value until engine reaches normal operating temperature and electronic EGR schedule has timed out (refer to ``Electronic Spark Control Specifications''). EGR Solenoid will then de-energize and voltmeter will indicate charging system voltage.
3. If system does not de-energize in specified amount of time, replace solenoid.
4. If voltmeter indicates charging system voltage before EGR schedule is complete, replace Spark Control Computer. If vehicle is started with engine at operating temperature, EGR solenoid will be energized for length of time delay schedule only and will then de-energize.