DTC P0138:00, P0158:00 [MZI-3.7]

id0102d2500000

DTC P0138:00 DTC P0158:00 | P0138:00: HO2S (RH) circuit high voltage P0158:00: HO2S (LH) circuit high voltage
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DETECTION CONDITION | • P0138:00 indicates that HO2S (RH) circuit high voltage • P0158:00 indicates that HO2S (LH) circuit high voltage • The HO2S signals are monitored for an over voltage condition. The code is set when the HO2S signal voltage is 1.5 V or more.
POSSIBLE CAUSE | • Short to power supply in the wiring harness or HO2S • 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 the repair order, then go to the next step.
2 | VERIFY RELATED SERVICE INFORMATION AVAILABILITY • Verify related Service Information availability. • Is any related Service Information available? | Yes | Perform repair or diagnosis according to the available Service Information. • If the vehicle is not repaired, go to the next step.
No | Go to the next step.
3 | VISUALLY INSPECT HO2S WIRING HARNESS Note • Disconnect the HO2S wiring harness connector. Only the suspect HO2S needs to be diagnosed. • Turn the ignition switch off. • Disconnect the suspect HO2S connector. • Visually inspect the HO2S wiring harness. ― Check the connector (both halves) for contamination ― Make sure the connector pins are fully seated • Is a concern present? | Yes | Repair if necessary. Go to Step 8.
No | Go to the next step.
4 | INSPECT WHETHER HO2S SIGNAL LEVEL IS TOO HIGH • Connect the suspect HO2S connector. • Turn the ignition switch to the ON position (engine running). • Access and monitor the following HO2S signal PID. ― P0138:00: O2S12 ― P0158:00: O2S22 • Is the voltage less than 1.1 V? | Yes | Go to the next step.
No | Go to Step 6.
5 | PERFORM THOROUGH WIGGLE TEST ON HO2S WIRING HARNESS • Turn the ignition switch off. • Turn the ignition switch to the ON position (engine off). • Access and monitor the suspect HO2S signal PID on Step 4. • Perform a thorough wiggle test on the suspect HO2S wiring harness. • Does the voltage change during the wiggle test? | Yes | Repair if necessary. Go to Step 8.
No | Perform the “INTERMITTENT CONCERN TROUBLESHOOTING”. Then go to the next step.
6 | INSPECT HO2S SIGNAL FOR SHORT TO POWER SUPPLY INSIDE SENSOR • Turn the ignition switch off. • Disconnect the suspect HO2S connector. • Start the engine and run it at idle. • Access and monitor the HO2S signal PID at Step 4. • Is the voltage less than 1.1 V? | Yes | Replace the suspect HO2S. (See HEATED OXYGEN SENSOR (HO2S) REMOVAL/INSTALLATION [MZI-3.7].) Then go to Step 8.
No | Go to the next step.
7 | INSPECT HO2S CIRCUIT FOR SHORT TO POWER SUPPLY IN WIRING HARNESS • Suspect HO2S connector is disconnected. • Turn the ignition switch off. • Disconnect the PCM connector. • Turn the ignition switch to the ON position (engine off). • Measure the voltage between suspect HO2S terminal B and body ground. • Is any voltage present? | Yes | Repair or replace suspected part, then go to the next step.
No | Go to the next step. (The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector.)
8 | VERIFY TROUBLESHOOTING OF DTC P0138:00, P0158:00 HAS BEEN COMPLETED • Verify that all disconnected connectors are reconnected. • Clear the DTC from the PCM memory using the M-MDS. • Perform the KOEO or KOER self-test. (See KOEO/KOER SELF TEST [MZI-3.7].) • Is the PENDING CODE for this DTC present? | Yes | Repeat the inspection from Step 1. • If the malfunction recurs, replace the PCM. (See PCM REMOVAL/INSTALLATION [MZI-3.7].) Go to the next step.
No | Go to the next step.
9 | VERIFY AFTER REPAIR PROCEDURE • Perform the “AFTER REPAIR PROCEDURE”. (See AFTER REPAIR PROCEDURE [MZI-3.7].) • Are any DTCs present? | Yes | Go to the applicable DTC inspection. (See DTC TABLE [MZI-3.7].)
No | Troubleshooting completed.