P0159

P0159
Aging of Oxygen Sensor After Three Way Catalytic Converter (TWC) (cylinders 4-6)

Function
To diagnose the oxygen sensor signals, the Engine Control Module (ECM) uses the form and frequency of the respective signal as a measuring value. The data to be calculated by the ECM are the time of the sensor voltage between positive and negative limits, the maximum and the minimum recognized sensor voltage values, oxygen sensor value toward rich, oxygen sensor value toward lean, sensing limits of oxygen sensing toward rich, sensing range of oxygen sensing, period duration of sensors ahead of the Three Way Catalytic Converter (TWC) and the sensor voltage ahead of the TWC.

Diagnosis Conditions
Diagnostic Trouble Code (DTC) P0159 is stored in the Engine Control Module (ECM), when the sensor voltage is longer than 9 sec. between 0.0623 V and 0.399V, i.e. that the sensor delivers a signal that is implausible for the ECM.

Conditions for the diagnosis of oxygen sensor signals:
- Sensor heating is active.
- Oxygen sensing is active.
- Sensor voltage ahead and after TWC is active.
- No Secondary Air Injection.
- No faults detected for fuel tank ventilation and Secondary Air Injection.

NOTE: If DTC P0159 is recorded in memory, heat oxygen sensors (road test under load, run engine with no load at high engine speed). Erase DTC memory and road test again during which the engine speed must be for 120 sec. between 950 1/min and 3000 1/min.

- Read DTC again. If DTC P0159 is again in memory, replace the respective oxygen sensor.





Diagnosis procedure
Connect system tester or scan tool and switch to menu point "DTC memory".
1. Connect system tester with adapter cable.
2. Switch ignition on.
3. Initiate diagnosis and advance to menu point "DTC memory"
4. Read DTC memory.

- If other faults found: Read DTC memory and correct faults.
- If DTC P0159 is found: Erase DTC memory, Road test vehicle, then recheck fault memory. See below.

Read DTC memory, correct faults.
1. Read DTC memory.
2. Correct faults according to Repair Manual.
3. Erase DTC memory.
4. Road test car as described under "Note" above.
5. Again read DTC memory.

- If no fault found: End
- If DTC P0159 is found: Erase DTC memory, Road test vehicle, then recheck fault memory. See below.

Road test after erasing DTC memory.
1. Erase DTC memory.
2. Heat oxygen sensors (road test under load, run engine with no load with high engine speed).
3. Road test vehicle. Engine speed at operating temperature must be between 950 1/min and 3000 1/min for 120 sec.
4. Connect system tester or scan tool and switch to menu point "DTC memory".

- No fault found: --> End
- If DTC P0159 is in memory: --> Replace oxygen sensor.