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

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

Exhaust Gas Recirculation (EGR) Wiring Diagram:

CIRCUIT DESCRIPTION:

The digital (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:

If a code is set, inspect EGR for damage.

Start and idle engine, enter ECM overrides ESO2, ESO3, ESO4. You should be able to discern a change in engine rpm as the ECM turns on the EGR. ESO2 should result in a small change and ESO4 in a large change in rpm. The engine may stall when ESO4 is turned "ON."