Diagnosis & Repair Procedure
WARNING: This page is about a different car, the 2002 Suzuki Grand Vitara. However, it is still accessible from the selected car via links, so may be relevant.
- Perform DTC CONFIRMATION TEST . If DTC P0141 is set, go to next step. If DTC P0141 is not set, problem is intermittent. System is okay at this time. See INTERMITTENTS TROUBLE SHOOTING - NO CODES article.
- Turn ignition off. Disconnect ECM (PCM) 26-pin connector C51-3. Disconnect HO2S 4-pin heater relay connector, located underhood on left fenderwell. See Figure . Using an ohmmeter, measure resistance between HO2S 4-pin heater relay harness connector E139 terminal No. 2 (Blue wire) and ECM (PCM) 26-pin harness connector C51-3 terminal No. 17 (White/Black wire). See Figure . If resistance is 5-7 ohms at 68°F (20°C), go to step 4 . If resistance is not 5-7 ohms at 68°F (20°C), go to next step.
- Check for short or open in Blue wire between HO2S heater relay and HO2S Bank 1, Sensor 2. Also check for short or open in White/Black wire between HO2S Bank 1, Sensor 2 and ECM (PCM) 26-pin harness connector C51-3. See ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL. If wires are okay, replace HO2S Bank 1, Sensor 2 and go to DTC CONFIRMATION TEST .
- Turn ignition on. Measure voltage between ground and HO2S 4-pin heater relay harness connector terminal No. 1 (Blue/White wire). Also measure voltage between ground and HO2S 4-pin heater relay harness connector E139 terminal No. 3 (Black/White wire). If 10-14 volts exist at both terminals, go to step 6 . If 10-14 volts do not exist at either terminal, go to next step.
- Check for blown HO2S fuse (15-amp) or IG METER fuse (20-amp) in instrument panel fuse/relay block. Replace blown fuse(s) as necessary. If fuses are okay, check for short or open in Black/White wire between HO2S heater relay and IG METER fuse (20-amp). Also check for short or open in Blue/White wire between HO2S heater relay and HO2S fuse (15-amp). See ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL. Repair as necessary and go to DTC CONFIRMATION TEST .
- Turn ignition off. Connect HO2S heater relay. Turn ignition on. Backprobing, measure voltage between ground and ECM (PCM) 26-pin connector C51-3 terminal No. 17 (White/Black wire). See Figure . If 10-14 volts exist, replace ECM (PCM) and go to DTC CONFIRMATION TEST . If 10-14 volts do not exist, go to next step.
- Check for short to ground in White/Black wire between HO2S Bank 1, Sensor 2 and ECM (PCM) 26-pin connector C51-3. If White/Black wire is okay, check HO2S heater relay operation. See RELAYS & SOLENOIDS in SYSTEM & COMPONENT TESTING. If HO2S heater relay is okay, replace ECM (PCM) and go to DTC CONFIRMATION TEST .