DTC P1127:00 [MZI-3.7]

id0102d2316700

DTC P1127:00 | Exhaust temperature out of range, HO2S tests not completed
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DETECTION CONDITION | • The HO2S monitor uses an exhaust temperature model to determine when the HO2S heaters are cycled ON. The test fails when the inferred exhaust temperature is below a minimum calibrated value.
POSSIBLE CAUSE | • Exhaust system too cool • Engine not operating long enough prior to carrying out the KOER self-test • 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 | EXHAUST TEMPERATURE OUT OF RANGE Note • Address all other DTCs before proceeding. • Turn the ignition switch to the ON position (Engine running) • Verify that the engine is at normal operating temperature. • Access the PCM and monitor the HO2S heater PID. • Is the PID state ON? | Yes | Perform the KOER self-test. (See KOEO/KOER SELF TEST [MZI-3.7].) Go to the next step.
No | Run the engine until the PID indicates ON. Perform the KOER self-test. (See KOEO/KOER SELF TEST [MZI-3.7].) Go to the next step.
4 | VERIFY TROUBLESHOOTING OF DTC P1127:00 HAS BEEN COMPLETED • Verify that all disconnected connectors reconnected. • Clear DTC from memory using M-MDS. • Start engine. • Perform the KOEO or KOER self-test. (See KOEO/KOER SELF TEST [MZI-3.7].) • Is same 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.
5 | 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.