Diagnosis & Repair
- Access ECM behind glove box. Turn ignition on. Using DVOM, backprobe connector and measure voltage between ground and terminals No. 27 (Gray/Blue wire), No. 28 (Gray/Green wire), No. 29 (Gray/Red wire) and No. 30 (Gray/Black wire) at ECM E14 connector. See Figure. If all readings are 9-14 volts, go to step 3). If any reading is not 9-14 volts, go to next step.
- Disconnect EGR valve connector. Turn ignition on. Measure voltage between ground and terminals No. 2 (Black/Red wire) and No. 5 (Black/Red wire) at EGR valve harness connector. If both readings are 9-14 volts, go to next step. If any reading is not 9-14 volts, check for open or short circuit in wiring harness between battery and EGR valve. Repair as necessary.
- Measure resistance between terminals No. 4 and 5, No. 5 and 6, No. 1 and 2 and between terminals No. 2 and 3 at EGR valve. See Fig 1. If each reading is 10-30 ohms, go to next step. If any reading is not 10-30 ohms, replace EGR valve.
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- Check for open or short circuit in wiring harness between EGR valve and ECM. See appropriate wiring diagram in appropriate WIRING DIAGRAMS
article. Repair as necessary. If wiring is okay, replace ECM and retest.