P0159

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 0V and 1V. 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 the HO2S's response time is too long, PCM sets P0159. MIL(Malfunction Indication Lamp) turns on when the malfunction lasts till consecutive 2 driving cycle.

DTC DETECTING CONDITION





SIGNAL WAVEFORM AND DATA





SPECIFICATION

(Reference only)






MONITOR DTC STATUS

1. Connect scantool to Data Link Connector(DLC).
2. IG "ON".
3. Select "Diagnostic Trouble Codes(DTCs)" mode, and then Press F4(DTAL) to check DTC's information from the DTCs menu
4. Read "DTC Status" parameter.




5. Is parameter displayed "Present fault"?
YES
> Go to "Component Inspection" procedure.
NO
> Clear DTC and check if this DTC is set after test-driving under enable conditions. If DTC isn't displayed after the test, it was intermittent fault. Go to "Verification of Vehicle Repair" procedure.

COMPONENT INSPECTION

1. Replace the HO2S.
2. Clear DTC with scantool.
3. Start the engine and warm it up until the radiator fan comes on( more than at least 10 minutes).
4. Drive at a steady speed between 45-55 mph(72-88 km/h) for 30 seconds.
5. Stop and then maintain idle state for 30 seconds in D-position.
6. Check if O2 sensor monitoring readiness is complete.
7. Does the scan tool show DTC P0139?
YES
> Substitute with a known - good PCM and check for proper operation.
If the problem is corrected, go to "Verification of Vehicle Repair" procedure.
NO
> Troubleshooting is finished.

NOTE:
There is a memory reset function on scantool that can erase optional parts automatically detected and memorized by PCM. Before or after testing PCM on the vehicle, use this function to reuse the PCM on the others

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 rediness test have been verified as " Complete "
5. Are any DTCs present ?
YES
> Go to the applicable troubleshoooting procedure.
NO
> System is performing to specification at this time.