Chart C-7 Exhaust Gas Recirculation (EGR) System Check

Chart C-7 - Exhaust Gas Recirculation (EGR) Flow Check:

EGR Solenoid Wiring Circuit:

Circuit Description:

The digital Exhaust Gas Recirculation (EGR) valve is designed to accurately supply EGR to an engine independent of intake manifold vacuum. The valve controls EGR flow from the exhaust to the intake manifold through three orifices which increment in size to produce seven combinations. When a solenoid is energized, the armature, with attached shaft and swivel pintle is lifted, opening the orifice.

The flow accuracy is dependent on metering orifice size only, which results in improved control.

Test Description: Number(s) below refer to circled number(s) on the diagnostic chart.
1. You should be able to discern a change in engine RPM as each solenoid is cycled 'ON." Solenoid #3 may cause the engine to stall when cycled "ON" at idle.
2. If the test light lights, the PCM and wiring are OK.

NOTICE: If the digital EGR valve shows signs of excessive heat, check the exhaust system for blockage (possibly a plugged converter) using the procedure found on CHART B-1. If the exhaust system is restricted, repair the cause; possibly an ignition misfire or an injector which is open due to one of the following:
A. Stuck.
B. Grounded driver circuit.
C. Possibly defective PCM.

If this condition is found the oil should be checked for possible fuel contamination.