Test C2 - EGR Valve Position Sensor (EVP)

Fig 1: EVP Sensor Circuit

1) Checking System Integrity  Visually check all wiring, harnesses, connectors and components for evidence of damage, overheating, shorting or looseness. If a fault is found, repair as necessary. If no faults are found, go to next step.

2) Checking EGR Voltage  Ensure engine is at operating emperature. With key off, install breakout box. Attach voltmeter to EVP and SIGRTN test pins. Turn ignition on. Install vacuum pump to EGR vacuum port. Slowly apply vacuum to EGR VALVE. Compare voltage to specifications shown in EGR SENSOR SPECIFICATIONS  . If voltage is within specification, EVP circuit is okay. Fault is in another circuit or ECA. If voltage is not within specification, go to step 3.

3) Checking EGR Signal Return  Remove EVP sensor connector. Using jumper wire, attach connector VREF (Green/Red) and SIGRTN (Green/Yellow) wire back to EVP sensor. Install vacuum pump to EGR vacuum port. Attach voltmeter to EVP and SIGRTN terminal on EVP sensor. Turn ignition on. Slowly apply vacuum to EGR VALVE.

4) Checking SIGRTN/VREF At EGR  Compare voltage to specifications shown in EGR SENSOR SPECIFICATIONS  . If voltage is within specification, repair EVP circuit between sensor and ECA. If voltage is not to specification, measure voltage between connector VREF wire and SIGRTN wire. Turn ignition on. If voltage is 4.5-5.5 volts replace EVP sensor. If not, go to TEST A7.