DTC 32: EGR Function
NOTE:
DO NOT
perform this test if DTC 12 is present.
- Check Vacuum Source To EGR Valve - Start engine and warm to operating temperature. Disconnect hose from EGR valve and check vacuum. Vacuum should not be present. Raise engine speed to about 2000 RPM and check vacuum. Vacuum should be present. If vacuum is not as specified, go to next step. If vacuum is as specified, inspect EGR system. See I SYS/COMP TESTS article in the ENGINE PERFORMANCE section. Repair or replace as necessary and perform FINAL CHECK in this article.
- Check Control Function - If vacuum is not present at about 2000 RPM, measure voltage between ECM terminal No. 102 (Gray wire) and ground. See Figure and Fig 1 . At idle, voltage should be about zero volts. At 2000 RPM, voltage should be battery voltage. If voltage is not as specified, go to next step. If voltage is as specified, inspect vacuum hose for clogging, cracks or proper connection. Repair vacuum hose as necessary.
- Check Power Supply - Turn ignition off. Disconnect EGR control solenoid valve wiring harness connector. Turn ignition on. Measure voltage between harness connector terminal "a" (White/Red wire) and ground. See Fig 2. If battery voltage is present, go to next step. If battery voltage is not present, check wiring harness and harness connectors between EGR control solenoid and ignition switch. Repair or replace as necessary.
- Check Output Signal Circuit - Turn engine off. Leave ECM disconnected. Check continuity between ECM terminal No. 102 and EGR control solenoid valve wiring harness connector terminal "b" (Gray wire) See Figure and Fig 3 . If continuity is present, go to next step. If continuity is not present, repair harness or connectors EGR control solenoid valve and ignition switch.
- Check Component - Inspect EGR control solenoid valve. See I SYS/COMP TESTS article in the ENGINE PERFORMANCE section. On California models, measure resistance of EGR temperature sensor. See I - SYS/COMP TESTS article in the ENGINE PERFORMANCE section. Repair or replace components as necessary and perform FINAL CHECK in this article. If components are okay, repair ECM pin terminals and/or wiring harness connector.