Exhaust Gas Recirculation: Testing and Inspection

Fig. 173 E.G.R. VACUUM BOOSTER CONNECTER:

INITIAL TEST
1. Check visually for leaks and good connection on the vacuum system.
2. Open E.G.R. vacuum booster connector. Remove wire opposite red-green wire.
3. Rejoin connector.
4. Start engine and run it until it reaches operating temperature. Allow engine to idle.
5. Ground the loose wire and check whether E.G.R. valve operates. Fig. 173.
6. Proceed in accordance with following three conditions:


E.G.R. vacuum valve operates and engine runs rough:
- Engine should run extremely rough, indicating a maximum amount of exhaust gas recirculation. In this case, the vacuum system is functioning correctly.
- Erase all fault codes as described under "CHECKING FAULT CODES".

Fig. 174 E.G.R. VACUUM CONTROLLER TEST:

E.G.R. vacuum valve does not operate and engine runs normally:
- Disconnect white vacuum hose from the E.G.R. vacuum booster. Check end of hose for vacuum. If vacuum is not present, check hose and rubber end joints. Fig. 174.

Fig. 175 E.G.R. VALVE TEST:

- Disconnect yellow hose from E.G.R. vacuum valve. Check the end of hose for vacuum. If vacuum is present, replace and test using a new E.G.R. vacuum valve. Fig. 175.
- If vacuum is not present, check hose and rubber end joints for leaks. If intact, replace and test with new vacuum booster.
- Erase all fault codes as described under "CHECKING FAULT CODES".


E.G.R. vacuum valve operates but engine runs normally or somewhat unevenly:
- Remove and clean E.G.R. pipes and vacuum valve.
- Erase all fault codes as described under "CHECKING FAULT CODES".