Vacuum Switching Valve (VSV)

Chart C-7 EGR VSV Schematic:

1. Disconnect ECM connector (GRN) from ECM with ignition switch turned "OFF."
2. Disconnect electrical connector from VSV.
3. Disconnect vacuum hoses from EGR valve (or EGR modulator) and throttle body.

Inspecting Wire Harness:

4. Turn ignition switch "ON" and check that battery voltage is applied to connector terminal "A." If not check wire harness (LT GRN/RED) or control relay for an open circuit.

Inspecting EGR VSV:

5. Reconnect VSV connector.
6. With ignition switch "ON," blow into hose "A." Air should come out of hose "B" and not out of filter. If otherwise, either VSV is defective or LT GRN/YEL wire harness is shorted to ground.

Grounding G5 Terminal:

Inspecting EGR VSV:

7. Using a fused jumper wire ground terminal "G5" of ECM connector. Turn ignition switch "ON" and blow into hose "A." Air should come out of filter and not out of hose "B." If result is not as described above, either VSV is defective or (LT GRN/YEL) wire harness is open.
8. Install vacuum hoses securely.
9. Connect ECM connector securely.