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Home >> Suzuki >> 2001 >> Vitara JS, 4D Utility, Standard >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - Self-Diagnostics >> Diagnostic Tests >> DTC P0135: Ho2S No. 1 Heater Circuit Malfunction >> Diagnosis & Repair Procedure
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Diagnosis & Repair Procedure

  1. Perform DTC CONFIRMATION TEST . If DTC P0135 is set, go to next step. If DTC P0135 is not set, problem is intermittent. System is okay at this time. See TROUBLE SHOOTING - NO CODES article.
  2. Turn ignition off. Disconnect HO2S No. 1 connector. Measure resistance between HO2S No. 1 connector terminals No. 3 (Gray wire) and 4 (Black/White). On vehicles with warm-up three-way catalytic converters (WU-TWC), resistance should be between 4.5-5.7 ohms at 68°F (20°C). On vehicles without WU-TWCs, resistance should be 11.7-14.3 ohms at 68°F (20°C). If resistance is as specified, go to next step. If resistance is not as specified, replace HO2S No. 1 and retest system.
  3. Reconnect HO2S No. 1 connector. Turn ignition on. Backprobing, measure voltage between ground and PCM 30-pin connector C51-2 terminal No. 4 (Gray wire). If reading is 10-14 volts, go to step  5. If reading is not 10-14 volts, check for open in Black/White wire between HO2S No. 1, IG fuse (20-amp) and PCM 26-pin connector C51-3 terminal No. 20. IG fuse (20-amp) is located in instrument panel fuse/relay block, under left side of instrument panel. Also check for short to ground or open in Gray wire between HO2S No. 1 and PCM 30-pin connector C51-2 terminal No. 4. See WIRING DIAGRAMS article. Go to next step.
  4. If wires are okay, check for poor terminal contact at HO2S No. 1 connector. If poor terminal contact is found, repair as necessary and go to DTC CONFIRMATION TEST . If terminal contact is okay, replace PCM and go to DTC CONFIRMATION TEST .
  5. Start engine and allow it to reach normal operating temperature. Backprobing, measure voltage between ground and PCM 30-pin connector C51-2 terminal No. 4 (Gray wire). If reading is 0-1 volt, problem is intermittent. System is okay at this time. See TROUBLE SHOOTING - NO CODES article. If reading is not 0-1 volt, disconnect PCM 30-pin connector C51-2. Check for poor terminal contact at PCM 30-pin connector C51-2. If poor terminal contact is found, repair as necessary and go to DTC CONFIRMATION TEST . If terminal contact is okay, replace PCM and go to DTC CONFIRMATION TEST .
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