P2272

P2272

Component Location:

General Description
The rear heated oxygen sensor is mounted on the rear side of the Catalytic Converter (warm-up catalytic converter) or in the rear exhaust pipe, which is able to detect catalyst efficiency. The rear heated oxygen sensor (HO2S) produces a voltage between 0 V and 1 V. This rear heated oxygen sensor is used to estimate the oxygen storage capability. If a catalyst has good conversion properties, the oxygen fluctuations are smoothed by the oxygen storage capacity of the catalyst. If the conversion provided by the catalyst is low due to aging, poisoning or misfiring, then the oxygen fluctuations are similar to signals from the front oxygen sensor.

DTC Description
Checking output signals from HO2S under detecting condition, if an output signal within the detecting condition lasts continuously, PCM sets P2272. MIL (Malfunction Indication Lamp) turns on when the malfunction lasts till consecutive 2 driving cycle.

DTC Detecting Condition:

Specification:

Schematic Diagram (Part 1):

Schematic Diagram (Part 2):

Signal Waveform:

Monitor Scantool Data
1. Connect scantool to DLC (Data Link Connector)
2. Warm up the engine to normal operating temperature.
3. Monitor "HO2S (B2S2)" parameter on scantool

Specification: 0.1 - 0.9 V






4. Does the "HO2S (B2S2)" parameter operates correctly?

YES - Fault is intermittent caused by poor contact in sensor's and/or PCM's connector or was repaired and PCM memory was not cleared. Thoroughly check connectors for looseness, poor connection, bending, corrosion, contamination, deterioration, or damage. Repair or replaces necessary and go to "Verification of Vehicle Repair" procedure

NO - Go to "Component Inspection" procedure.

Component Inspection
1. Visual Inspection
1. Visually check HO2S as follow.
- Contamination, deformation or age of HO2S (B2/S2)

2. Is the HO2S (B2/S2) normal?

YES - Go to "Check performance of HO2S" as follows.

NO - Substitute with a known-good HO2S (B2S2) and check for proper operation. If the problem is corrected, replace HO2S (B2S2) and then go to "Verification of Vehicle Repair" procedure.

2. Check performance of HO2S
1. Connect scantool to DLC (Data Link Connector)
2. Warm up the engine to normal operating temperature.
3. Monitor signal waveform of HO2S with scantool.

Specification: 0.1 - 0.9 V.






4. Is the HO2S (B2S2) working properly?

YES - Substitute with a known-good PCM and check for proper operation. If the problem is corrected, replace PCM and then go to "Verification of Vehicle Repair" procedure.

CAUTION: There is a memory reset function on scantool that can erase optional parts automatically detected and memorized by PCM.

NO - Substitute with a known-good HO2S (B2S2) and check for proper operation. If the problem is corrected, replace HO2S (B2S2) and then go to "Verification of Vehicle Repair" procedure.

Verification of Vehicle Repair
After a repair, it is essential to verify that the fault has been corrected.
1. Monitor and record the Freeze Frame Data for the Diagnostic Trouble Code (DTC) which has been diagnosed.
2. Using a Scantool, Clear the DTCs
3. Operate the vehicle within conditions noted in the freeze frame data or enable conditions
4. Monitor that all readiness test have been verified as "Complete"
5. Are any DTCs present?

YES - Go to the applicable troubleshooting procedure.

NO - System is performing to specification at this time.