Electronic Linear EGR Valve

DTC 32 W/CMFI & Tier 1:

Linear EGR Circuit W/CMFI & Tier 1:

Circuit Description:
The PCM operates the linear EGR valve to control exhaust gas recirculation, by providing a ground control that commands the pintle valve away from it's seat allowing exhaust gas through the valve.
The PCM monitors EGR effectiveness by de-energizing the EGR control, thereby, shutting "OFF" the EGR valve. With the EGR valve closed, and 02S fluctuating normally, fuel integrator counts will be greater than they were during normal EGR operation. If the change is not within the calibrated window, after failing the test twice a DTC 32 will be set.

The PCM will check EGR operation when:

- Throttle position between 10% and 25% angle.

- Steady throttle with no more then 2% change in throttle.

- Above 32 mph "Closed Loop" operation.

- Max short term fuel trim less then 6 counts for 3.2 seconds.

- Desired EGR command greater then then 40%.

- MAP above 47.5 kPa or less then 15 kPa.

Test Description: Number(s) below refer to circled number(s) on the diagnostic chart.

1. This step checks the pintle's ability to be commanded to the desired position.

2. This step checks for voltage to the linear EGR valve to verify if the problem is in the ignition feed circuit.

3. This cheeks the PCM control circuit by jumpering across the CKT 435 and CKT 439 with a test light and grounding the diagnostic connector to command the EGR "ON."

Diagnostic Aids:
Before replacing PCM, use an ohmmeter and check the resistance of each PCM controlled relay and solenoid coil.
With DVOM, check resistance of EGR pins.
A to E 7.8 - 8.6 ohms
B to D Above 3K ohms
D to C From 0.7 to 4.0K ohms when slowly moving pintle valve inward.