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Home >> Suzuki >> 2003 >> XL-7 Base, 4WD >> Repair and Diagnosis >> External Pages >> Different car >> Section 18 (Engine Controls - Self-Diagnostics) >> Diagnostic Tests >> DTC P0031 Or DTC P0032 >> Diagnosis & Repair Procedure
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Diagnosis & Repair Procedure

WARNING: This page is about a different car, the 2002 Suzuki XL-7. However, it is still accessible from the selected car via links, so may be relevant.
  1. If engine system check has been performed, go to next step. If engine system check has not been performed, go to A4: ENGINE SYSTEM CHECK  under SYSTEM TESTS.
  2. Turn ignition off. Disconnect Bank 1 HO2S No. 1 4-pin harness connector. Bank 1 HO2S No. 1 is located in left exhaust pipe before catalytic convertor. Measure resistance between Bank 1 HO2S No. 1 pigtail connector terminal No. 3 (Green wire) and No. 4 (Blue wire). See Fig 1. Resistance should be 5.0-6.4 ohms at 68°F (20°C). If resistance is as specified, go to next step. If resistance is not as specified, replace HO2S. After repair, repeat DTC CONFIRMATION TEST .
  3. Disconnect HO2S heater relay. HO2S heater relay is located on left fender well. See Fig 2. Turn ignition on. Measure voltage between ground and HO2S heater relay socket cavity No. 3 (Black/White wire). See Fig 3. Also, measure voltage between ground and HO2S heater relay socket cavity No. 1 (Blue/White wire). If voltage readings at both measurements is 10-14 volts, go to step  5. If voltage readings are not as specified, go to next step.
  4. Check for blown HO2S (15-amp) or IG METER (20-amp) fuses. Fuses are located in underhood fuse and relay box. If fuses are okay, check for open or short to ground in Black/White wire between IG METER fuse and HO2S heater relay. See WIRING DIAGRAMS article. Also, check for open or short to ground in Blue/White wire between HO2S fuse and HO2S heater relay. If problem is found, repair as necessary. After repair, repeat DTC CONFIRMATION TEST .
  5. Turn ignition off. Install HO2S heater relay. Disconnect ECM 30-pin harness connector C51-2. ECM is located under instrument panel, behind glove box. See Figure. Measure voltage between ground and ECM harness connector C51-2 terminal No. 4 (Green wire). See Figure. If voltage reading is 10-14 volts, substitute a known good ECM, and repeat DTC CONFIRMATION TEST . If DTC does not reset, testing is complete. If voltage readings are not as specified, go to next step.
  6. Check for short to ground in Green wire between Bank 1 HO2S No. 1 and ECM. See WIRING DIAGRAMS article. If no problem with wiring is found, replace HO2S heater relay. If problem persists after repairs, substitute a known good ECM, and repeat DTC CONFIRMATION TEST .
Fig 1: Identifying Heated Oxygen Sensor No. 1 Pigtail Connector Terminals
G00163659Courtesy of SUZUKI OF AMERICA CORP.
Fig 2: Locating Heated Oxygen Sensor Heater Relay
G00163687Courtesy of SUZUKI OF AMERICA CORP.
Fig 3: Identifying Heated Oxygen Sensor Heater Socket Cavities
G00163688Courtesy of SUZUKI OF AMERICA CORP.
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