Troubleshooting

Fig. 69 Vacuum & voltage chart.:

VACUUM AVAILABLE FOR CONDITION 1 OR NO VACUUM AVAILABLE FOR CONDITION 2 & 3

1. Check for proper vacuum hose routing. If routing is satisfactory, replace EGR control valves A and B.

VOLTAGE & VACUUM ARE AVAILABLE FOR CONDITION 4

1. Replace EGR control solenoid valve A and repeat test.

NO VOLTAGE AVAILABLE FOR CONDITION 1 OR 4, OR VOLTAGE AVAILABLE FOR CONDITION 2 OR 3

1. Check thermosensor and vacuum switch C for proper operation. Replace as required.
2. Check for voltage at control unit black/yellow wire connector with ignition switch On. If voltage is not present, check wiring for damage and defects.
3. Check for continuity between control unit brown/black wire and suitable ground. Continuity should be present.