Circuit Description
The Electronic Vacuum Regulator Valve (EVRV) solenoid which is a normally closed solenoid (allows a vacuum to pass when energized) controls the EGR valve. The ECM pulses the solenoid to turn ON and regulate the EGR. The ECM diagnoses the system using an internal EGR test procedure.
The ECM controls the EGR based on the following inputs:
| • | Engine Coolant Temperature (ECT) -- above 25°C |
| • | TP signal -- OFF idle |
| • | MAP |
If DTC 24 is stored, use that table first.
DTC 32 detects a faulty solenoid, a faulty vacuum supply, a faulty EGR valve, or a plugged passage. This table checks for plugged EGR passages, a sticking EGR valve, or a stuck open or inoperative solenoid.
Diagnostic Aids
Check the vacuum lines thoroughly for the proper routing. The vacuum source goes to the orifice side of the EGR valve. Refer to Vehicle Emission Control Information Label.
The suction from the shop exhaust hoses can alter the exhaust backpressure and may affect the functional check of the EGR system.
Test Description
The numbers below refer to the step numbers on the Diagnostic Table.
-
With the ignition ON and the engine OFF, the solenoid should not energize and the vacuum should not pass to the EGR valve.
-
Grounding the diagnostic terminal will energize and allow the vacuum to pass to the valve.
-
This test checks for plugged EGR passages. If the passages are plugged, the engine may have severe detonation on acceleration.
-
The EGR solenoid will not energize in neutral. This test determines if the ECM receives the neutral switch input.
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
1 | Did you perform the Powertrain On-Board Diagnostic (OBD) System Check? | -- | ||
Does the EGR Valve move? | -- | |||
Does the EGR move? | -- | |||
Does the idle roughen? | -- | Go to Step | ||
Is the EGR vacuum less than the specified value? | 34 kPa (10 in Hg) | |||
6 | No trouble found. The EGR system is OK. | -- | -- | |
7 | Clean or replace the EVRV filter. Is the action complete? | -- | -- | |
8 |
Did you find a problem? | -- | ||
9 |
Does the gauge indicate a vacuum? | -- | ||
10 | Refer to DTC 32 Exhaust Gas Recirculation (EGR) Error . Is the action complete? | -- | -- | |
11 |
Does the EGR Valve move? | -- | Go to Step | |
12 | Replace the EVRV Solenoid. Is the action complete? | -- | -- | |
13 |
Is the orifice plugged? | -- | ||
14 | Replace the EGR Valve. Is the action complete? | -- | -- | |
15 |
Is the EGR control circuit grounded? | -- | ||
16 | Replace the Control Module. Is the action complete? | -- | -- | |
17 | Operate the vehicle within the conditions of the original symptom. Does the system now operate properly? | -- | System OK | Refer to Diagnostic Aids |
