DTC P2270, P2272 [MZI-3.7]


id0102d2882400

DTC P2270

DTC P2272

P2270: Rear HO2S (RH) signal stuck lean

P2272: Rear HO2S (LH) signal stuck lean

DETECTION CONDITION
•  The downstream HO2S is forced rich and monitored by the PCM. The test fails if the PCM does not detect the output of the HO2S in a calibrated amount of time
POSSIBLE CAUSE
•  Leakage exhaust gas
•  Rear HO2S malfunction
•  PCM malfunction

Diagnostic procedure

STEP

INSPECTION

ACTION

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
Perform the PCM reprogramming procedure.
Then go to the next step.
3
VERIFY RELATED PENDING CODE OR STORED DTCs
•  Turn the ignition switch off then to the ON position (Engine off).
•  Verify the related PENDING CODE or stored DTCs using the M-MDS.
Yes
Go to the appropriate DTC troubleshooting.
No
Go to the next step.
4
IDENTIFY TRIGGER DTC FOR FREEZE FRAME DATA
•  Is DTC P2270 or P2272 on the FREEZE FRAME DATA?
Yes
Go to the next step.
No
Go to the troubleshooting for the DTC on the FREEZE FRAME DATA.
5
INSPECT FOR EXHAUST GAS LEAKAGE
Visually inspect for exhaust gas leakage between the TWC and the rear HO2S.
•  Is there any malfunction?
Yes
Repair or replace the malfunctioning parts.
Then go to the next step.
No
Go to the next step.
6
INSPECT REAR HO2S
•  For DTC P02270 Inspect the rear HO2S(RH)
•  For DTC P02272 Inspect the rear HO2S(LH)
•  Is there any malfunction?
Yes
Inspect the related wiring harness.
If there is no malfunction, repair or replace the suspect HO2S.
Then go to the next step.
No
Go to the next step.
7
VERIFY TROUBLESHOOTING OF DTC P2270, P2272 HAS BEEN COMPLETED
•  Verify that all disconnected connectors are reconnected.
•  Turn the ignition switch to the ON position (Engine off).
•  Clear the DTC from the PCM memory using the M-MDS.
•  Perform no load racing at the engine speed of 2,500—3,500 rpm for 60s or more, then idle the engine for 60s or more.
•  Perform the KOEO and KOER self-test.
•  Retrieve DTCs using the M-MDS.
•  Is the PENDING CODE for this DTC present?
Yes
Replace the PCM, then go to the next step.
No
Go to the next step.
8
VERIFY AFTER REPAIR PROCEDURE
•  Perform “AFTER REPAIR PROCEDURE”.
•  Are any DTC present?
Yes
Go to the applicable DTC inspection.
No
Troubleshooting completed.