Diagnosis & Repair Procedure
WARNING: This page is about a different car, the 2002 Mazda Protege5 and 2002 Mazda Protege. However, it is still accessible from the selected car via links, so may be relevant.
- Ensure FREEZE FRAME DATA has been recorded. Check for related service bulletins. Repair as necessary and go to next step.
- Turn ignition switch off. Disconnect front HO2S 4-pin harness connector. Check for damaged or corroded front HO2S connector terminals. Repair as necessary, and go to step 6. If connector terminals are okay, go to next step.
- Measure resistance between front HO2S 4-pin connector terminals "C" and "D". See Figure. If resistance is about 5.6 ohms, go to next step. If resistance is not as specified, replace front HO2S and go to step 6.
- Turn ignition switch off. Disconnect PCM 104-pin harness connector. See Figure. Check for damaged or corroded PCM connector terminals. Repair as necessary, and go to step 6. If connector terminals are okay, go to next step.
- Turn ignition switch on. Check for voltage between ground and front HO2S 4-pin harness connector terminal "D" (Light Green/Red wire). See Figure. If battery voltage is not present, go to next step. If battery voltage is present, check for short to power in Light Green/Red wire between front HO2S 4-pin harness connector terminal "D" and PCM 104-pin harness connector terminal No. 94. See WIRING DIAGRAMS article. Go to next step.
- Reconnect all connectors. Clear DTCs. See CLEARING DIAGNOSTIC TROUBLE CODES under SELF-DIAGNOSTIC SYSTEM. Start engine and allow it to reach normal operating temperature. Check for DTCs. See RETRIEVING DIAGNOSTIC TROUBLE CODES under SELF-DIAGNOSTIC SYSTEM. If DTC P0032 is present, replace PCM and go to next step. If DTC P0032 is not present, go to next step.
- Cycle ignition switch from off to on. Check for DTCs. See RETRIEVING DIAGNOSTIC TROUBLE CODES under SELF-DIAGNOSTIC SYSTEM. If no other DTCs are present, testing is complete. If any other DTC is present, go to applicable test and repair.