Pinpoint Test EVP - EGR Valve Position (EVP) Sensor

Fig 1: Identifying EVP Circuit & Connector (EVP)

1)  Inspect hoses and connections between intake manifold and EGR valve. If all appears okay, go to next step. Repair hoses or connections as necessary.

2)  Turn ignition off. Connect vacuum gauge between EGR valve and vacuum hose going to EGR valve. Start engine. Warm engine to normal operating temperature. Observe vacuum gauge while assistant drives vehicle. If gauge indicates about 5 in. Hg at normal cruise, and zero in. Hg at idle, deceleration, and high speed, go to next step. If gauge indicates otherwise, inspect hoses for leaks, damage, or obstructions. If hoses are okay, repair EGR system.

3)  Turn ignition off. Install BOB, leaving PCM connected. Connect vacuum tester to EGR valve vacuum port. Turn ignition on. Measure voltage between BOB test pins EVP and SIGRTN while applying vacuum to EGR valve. If voltage does not increases smoothly from approximately 0.8 volt at zero vacuum to approximately 5.0 volts at 5.9 in. Hg., go to next step. If voltage is as specified, EVP circuit is okay. Return to QUICK TESTS if sent here from there; otherwise temporarily substitute known good PCM and retest.

4)  Turn ignition off. Unplug EVP connector. Turn ignition on. Measure voltage at VREF terminal (Light Green/Red wire) at EVP harness connector. If voltage is 4.5-5.0 volts, go to next step. If voltage is not as specified, go to PINPOINT TEST VREF.

5)  Turn ignition off. Measure resistance between at SIGRTN terminal (Yellow/Green wire) at EVP harness connector and ground. If resistance is less than 5 ohms, go to next step. If resistance is not as specified, repair Yellow/Green wire.

6)  Measure resistance between BOB test pins EVP and VREF. If resistance is not greater than 10,000 ohms, repair short between EVP (Yellow) and VREF (Light Green/Red) wires. If resistance is greater than 10,000 ohms, replace EVP sensor.