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DTC P0031 [AJ] (VIN: JMZ LW19J7*# 300001-, JM0 LW10J300 300001-301405, JM6 LW10J300 300001-, JM8 LW28J**# 300001-301513)

BME010200001201

DTC P0031 | HO2S heater (Front, RH) circuit low
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DETECTION CONDITION | • The PCM monitors the HO2S heater (Front, RH) control signal at PCM terminal 93. If PCM turns the HO2S heater (Front, RH) off but HO2S heater (Front, RH) circuit has low voltage, the PCM determines that the HO2S heater (Front, RH) circuit has malfunction.

  Note

  • The HO2S heater (Front, RH) is controlled by a duty signal.

Diagnostic support note
• This is a continuous monitor (O2 sensor heater).
• MIL illuminates if PCM detects the above malfunction condition in two consecutive drive cycles.
• PENDING CODE is available if PCM detects the above malfunction condition during first drive cycle.
• FREEZE FRAME DATA is available.
• DTC is stored in PCM memory.
POSSIBLE CAUSE | • HO2S (Front, RH) malfunction • Open circuit between the ignition switch and HO2S (Front, RH) terminal C • Open circuit between the HO2S (Front, RH) terminal D and PCM terminal 93 • Short to ground circuit between HO2S (Front, RH) terminal D and PCM terminal 93
• Poor connection at HO2S (Front, RH) or PCM connector
• PCM malfunction

Diagnostic procedure

STEP | INSPECTION | ACTION
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1 | VERIFY FREEZE FRAME DATA HAS BEEN RECORDED • Has FREEZE FRAME DATA been recorded? | Yes | Go to the next step.
No | Record FREEZE FRAME DATA on repair order, then go to the next step.
2 | VERIFY RELATED SERVICE INFORMATION AVAILABILITY • Check for related Service Information availability. • Is any related Service Information available? | Yes | Perform repair or diagnosis according to available Service Information. • If vehicle is not repaired, go to the next step.
No | Go to the next step.
3 | INSPECT HO2S (FRONT, RH) CONNECTOR FOR POOR CONNECTION • Turn the ignition switch off. • Disconnect the HO2S (Front, RH) connector. • Inspect for poor connection (such as damaged/pulled-out pins, corrosion). • Is there any malfunction? | Yes | Repair or replace terminal, then go to Step 9.
No | Go to the next step.
4 | INSPECT HO2S HEATER (FRONT, RH) • Inspect the HO2S heater (Front, RH). (See HEATED OXYGEN SENSOR (HO2S) INSPECTION [AJ] (VIN: JMZ LW19J7*# 300001-, JM0 LW10J300 300001-301405, JM6 LW10J300 300001-, JM8 LW28J**# 300001-301513).) • Is the HO2S heater (front, RH) normal? | Yes | Go to the next step.
No | Replace the HO2S (Front, RH), then go to Step 9.
5 | INSPECT POWER CIRCUIT OF HO2S HEATER (FRONT, RH) FOR OPEN CIRCUIT • Turn the ignition switch to the ON position (Engine off). • Measure the voltage between HO2S (Front, RH) terminal C (wiring harness-side) and body ground. • Is the voltage B+? | Yes | Go to the next step.
No | Repair or replace the wiring harness for open circuit, then go to Step 9.
6 | INSPECT PCM CONNECTOR FOR POOR CONNECTION • Turn the ignition switch off. • Disconnect the PCM connector. • Inspect for poor connection (such as damaged/pulled-out pins, corrosion). • Is there any malfunction? | Yes | Repair the terminal, then go to Step 9.
No | Go to the next step.
7 | INSPECT CONTROL CIRCUIT OF HO2S HEATER (FRONT, RH) FOR SHORT TO GROUND • Inspect for continuity between HO2S (Front, RH) terminal D (wiring harness-side) and body ground. • Is there continuity? | Yes | Repair or replace the wiring harness for short to ground, then go to Step 9.
No | Go to the next step.
8 | INSPECT CONTROL CIRCUIT OF HO2S HEATER (FRONT, RH) FOR OPEN CIRCUIT • Disconnect the PCM connector. • Inspect for continuity between HO2S (Front, RH) terminal D (wiring harness-side) and PCM terminal 93. • Is there continuity? | Yes | Go to the next step.
No | Repair or replace the wiring harness for open circuit, then go to Step 9.
9 | VERIFY TROUBLESHOOTING OF DTC P0031 COMPLETED • Make sure to reconnect all disconnected connectors. • Clear the DTC from the PCM memory using the WDS or equivalent. • Start the engine and warm it up completely. • Is the same PENDING CODE of DTC present? | Yes | Replace the PCM, then go to the next step.
No | Go to the next step.
10 | VERIFY AFTER REPAIR PROCEDURE • Perform "After Repair Procedure". (See AFTER REPAIR PROCEDURE [AJ].) • Is there any DTC present? | Yes | Go to the applicable DTC inspection. (See DTC TABLE [AJ] (VIN: JMZ LW19J7*# 300001-, JM0 LW10J300 300001-301405, JM6 LW10J300 300001-, JM8 LW28J**# 300001-301513).)
No | Troubleshooting completed.