DN44 - Check EGR Valve Function

- Key "OFF".

- Install a tachometer, rotunda 059-00010 or equivalent.

- Disconnect the Idle Air Control (IAC) solenoid electrical connector.

- Remove and plug the vacuum line to the EGR valve.

- Start engine, idle with transmission in NEUTRAL and observe idle speed. If necessary, adjust idle speed.

- Slowly apply 7-34 kPa (15-10 in-Hg) to the EGR valve with a hand vacuum pump.

- Does the idle speed drop more than 100 rpm with vacuum applied and return to normal (+/- 25 rpm) after the vacuum is removed?

Yes -- The EGR valve is OK. Replace EGR Valve Position (EVP) sensor. Reconnect all components. Rerun quick test. Quick Test Appendix (Detailed Testing Instructions)

No -- Replace the EGR valve if it does not hold vacuum. If the EGR valve does hold vacuum, remove and inspect it for binding or other damage. Service or replace EGR valve as necessary. Rerun quick test. Quick Test Appendix (Detailed Testing Instructions)