Diagnosis & Repair Procedure
WARNING: This page is about a different car, the 1997 Mazda Millenia. However, it is still accessible from the selected car via links, so may be relevant.
- Inspect all applicable harness connectors. Repair as needed. If all connectors are okay, go to next step.
- Turn ignition on. Access ECM harness connector. ECM is mounted in front of center console, below radio. Using voltmeter, backprobe applicable PCM harness connector. Measure voltage between ground and terminal No. 3R. If voltage is about .8 volt, go to step 8). If voltage is not about .8 volt, go to next step.
- Disconnect EGR valve position sensor harness connector. Measure voltage between ground and terminal "B". If 5 volts is present, go to next step. If 5 volts is not present, check for open or short in Light Green/Red wire.
- Turn ignition off. Disconnect PCM harness connector. Check continuity between terminal "A" on EGR valve position sensor harness connector and terminal No. 3AB on PCM harness connector. If continuity exists, go to next step. If continuity does not exist, repair Black/Yellow wire.
- Check continuity between terminal "C" on EGR boost sensor harness connector and terminal No. 3R on PCM harness connector. If continuity exists, go to next step. If continuity does not exist, repair Red/Black wire.
- Inspect EGR valve position sensor. See appropriate SYSTEM/COMPONENT TESTS - 2.3L article. Replace as needed. If EGR valve position sensor is okay, go to next step.
- Erase DTCs. See CLEARING CODES in SELF-DIAGNOSTIC SYSTEM section. If DTC resets, replace PCM. If DTC is not present, intermittent poor harness connection may have caused DTC to originally set.