Exhaust Gas Recirculation: Testing and Inspection

Chart C-7:

EGR VSV Wiring Diagram:

CIRCUIT DESCRIPTION:

The EGR Vacuum Switching Valve (VSV) solenoid is controlled by the ECM. The VSV solenoid is supplied with battery voltage. The ECM will switch to ground to turn the solenoid "ON" for EGR operation.

TEST DESCRIPTION: The numbers below refer to circled numbers on the diagnostic chart.

1. This test checks that the EGR valve is mechanically functional.

2. This test checks that vacuum is available to operate the EGR valve.

3. This test checks that the EGR (VSV) solenoid is operating properly.

DIAGNOSTIC AIDS:

Be sure to check hoses for proper vacuum supply. Check hoses for being plugged, kinked, or deteriorated.