Diagnosis & Repair Procedure
WARNING: This page is about a different car, the 2002 Mazda 626. However, it is still accessible from the selected car via links, so may be relevant.
- Perform DTC confirmation procedure. See DTC CONFIRMATION PROCEDURE under SELF-DIAGNOSTIC SYSTEM. Check for DTCs during KOEO and KOER self-test. See RETRIEVING DIAGNOSTIC TROUBLE CODES under SELF-DIAGNOSTIC SYSTEM. If DTC P0141 is present, go to next step. If DTC P0141 is not present, problem is intermittent. See INTERMITTENTS in TROUBLE SHOOTING - NO CODES article.
- Measure resistance between right rear HO2S connector Brown/Black wire and Red/Black wire terminals. If resistance is about 6 ohms, go to next step. If resistance is not as specified, replace right rear HO2S and go to step 8 .
- Turn ignition on. Measure voltage between ground and right rear HO2S harness connect terminal Red/Black wire. If battery voltage is present, go to next step. If battery voltage is not present, repair open in Red/Black wire. See WIRING DIAGRAMS article. Go to step 8 .
- Measure voltage between ground and right rear HO2S harness connector terminal Brown/Black wire. If battery voltage is not present, go to next step. If battery voltage is present, repair short to power in Brown/Black wire. See WIRING DIAGRAMS article. Go to step 8 .
- Turn ignition off. Check for continuity between ground and right rear HO2S harness connect terminal Brown/Black wire. If continuity is not present, go to next step. If continuity is present, repair short to ground in Brown/Black wire. See WIRING DIAGRAMS article. Go to step 8 .
- Disconnect PCM connector. Check for loose, damaged or corroded connector terminals. Repair as necessary, and go to step 8 . If connector terminals are okay, go to next step.
- Check for continuity of Brown/Black wire between right rear HO2S harness connector terminal "D" and PCM harness connector terminal No. 95. See Figure . If continuity is present, go to next step. If continuity is not present, repair open in Brown/Black wire. See WIRING DIAGRAMS article. Go to next step.
- Reconnect all connections. Clear DTCs. See CLEARING DIAGNOSTIC TROUBLE CODES under SELF-DIAGNOSTIC SYSTEM. Perform KOEO and KOER self-test. Check for DTCs. See RETRIEVING DIAGNOSTIC TROUBLE CODES under SELF-DIAGNOSTIC SYSTEM. If DTC P0141 is present, replace PCM and go to next step. See REMOVAL, OVERHAUL & INSTALLATION article. On vehicles equipped with immobilizer system, reprogram ignition key identification numbers. See COMPUTER RELEARN PROCEDURES - IMPORT article in GENERAL INFORMATION. If DTC P0141 is not present, go to next step.
- Perform DTC confirmation procedure. See DTC CONFIRMATION PROCEDURE under SELF-DIAGNOSTIC SYSTEM. Check for DTCs. See RETRIEVING DIAGNOSTIC TROUBLE CODES under SELF-DIAGNOSTIC SYSTEM. If any other DTC is present, go to appropriate test.