Test EVP - EGR Valve Position Sensor

Fig 1: Identifying EVP Connector Terminals

1) Checking System Integrity  Visually check all wiring, connectors and components for evidence of damage, shorting or looseness. If a fault is found, repair as necessary. If no fault is found, go to step 2).

2) Checking EGR Voltage  Ensure engine is at operating temperature. Turn ignition off. Install breakout box, leaving ECA disconnected. Install vacuum pump to EGR vacuum port. Attach voltmeter to EVP and SIGRTN test pins. Turn ignition on.

3)  Slowly apply vacuum to EGR valve. Compare voltmeter readings to specifications shown in EVP 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 4).

4) Checking EGR Signal Return  Remove EVP sensor connector. Using jumper wire, attach connector VREF (Green/Red wire) and SIGRTN (Green/Yellow wire) back to matching terminal on EVP sensor. Install vacuum pump to EGR vacuum port.

5)  Attach voltmeter to EVP and SIGRTN terminal on EVP sensor. Turn ignition on. Slowly apply vacuum to EGR VALVE. Compare voltage to specifications shown in VOLTAGE SPECIFICATIONS (EVP SENSOR)  . If voltage is within specification, repair EVP circuit between sensor and ECA.

6) Checking SIGRTN/VREF At EGR  If voltage is not to specification, turn ignition on. Measure voltage, at wiring harness connector, between VREF terminal (Green/Red wire) and SIGRTN terminal (Green/Yellow wire) of connector. If voltage is 4.5-5.5 volts, replace EVP sensor. If voltage is not as specified, go to CIRCUIT TEST VREF.