P0130

DIAGNOSTIC TROUBLE CODES P0130, P0131, PO132
Oxygen sensor, malfunctioning or not working at all

Fault Symptom.
CHECK ENGINE lamp (MIL) on.
Any other trouble codes (pressure sensors).
A malfunctioning oxygen sensor will rarely be the cause of poor engine performance. Other faults which lead to the generation of an oxygen sensor trouble code may on the other hand give rise to poor engine performance, depending on their nature.

Conditions.
The oxygen sensor indicates lean mixture/low voltage or rich mixture/high voltage for than 30 seconds.

DIAGNOSTIC PROCEDURE

IMPORTANT: A DTC may be generated if the fuel tank runs dry.

1. Checking Additional Diagnostic Trouble Codes In The Trionic System
Use the Scan Tool to obtain readouts of all the diagnostic trouble codes.

If diagnostic trouble codes P0105, P0106, P0107, P0108, manifold absolute pressure sensor, are present, fault diagnosis should be started there.

2. Checking For Air Leakage
Check that no air leakage occurs at the following places:
- the hose between the pressure sensor and the intake manifold
- the hose between the fuel pressure regulator and the intake manifold.

Important: The oxygen sensor obtains reference oxygen from the ambient air via the connecting cables. Contact cleaner and grease must therefore not be used on the oxygen sensor connectors.





3. Checking The Oxygen Sensor Mounting
A poor ground connection due to corrosion could give rise to malfunctions.

Connect a 12V/60W bulb across the oxygen sensor body and battery positive. The bulb should light up.

- If it does not, unscrew the oxygen sensor and clean the threads.

4. Checking The Operation Of The Pressure Sensor
Turn the ignition switch to the ON position and then back to the OFF position.
Connect the Scan Tool.
Select "READ FUNCTIONS".
Select "INTAKE PRESSURE".

The Scan Tool should show a reading of about 102 kPa.
NOTE: The reading is dependent on barometric pressure.

First build up a positive pressure of 0.6 bar and then a negative pressure of -0.6 bar. Use a pressure gauge and a pressure/vacuum pump.

The Scan Tool should show readings of 160 ±5 kPa and 40 ±5 kPa (slightly lower readings might be obtained at high altitudes).

The readings are designed to reveal any shift in the operating range of the pressure sensor.

If the readings are OK, continue with point 5.

If the readings are no OK, change the pressure sensor.






5. Check
- That the fuel pressure is correct
- That the EVAP canister purge valve closes when energized (it is normally open when no current is applied to it).
- That the fuel tank has not run dry
- That air leakage does not occur in the exhaust system ahead of the oxygen sensor or at its mounting points.
- That the engine oil is not diluted with fuel.







6. Checking The Electrical Interfaces Of The Oxygen Sensor
Unplug the oxygen sensor's 4-pin connector.

Fit a conventional 1.5 V battery in good condition in place of the oxygen sensor.

Connect the battery's positive pole to pin 4 of the connector. Connect the battery's negative pole to a good grounding point on the engine.

Ignition switch in the ON position.
Use the Scan Tool.
Select "READ FUNCTIONS"
Select" OXYGEN SENSOR"

The reading shows whether the control module and wiring as far as the oxygen sensor are in good working order.

The Scan Tool should show a reading of about 1.4 V.

NOTE: In the event of a break in the oxygen sensor's reference ground between grounding point G7S and pin 47 of the control module, the Scan Tool will show a reading of about 0.5 V.

If the reading is between 0.5 V and about 1.2 V, continue with point 7.

If the reading is about 1.4 V, continue with point 8.

If the reading is less than 0.5 V, continue with point 9.

IMPORTANT: The oxygen sensor obtains reference oxygen from the ambient air via the connecting cables. Contact cleaner and grease must therefore not be used on the oxygen sensor connectors.







7. Checking The Oxygen Sensor's Ground Connection
Check the cable between G7S and pin 47 of the control module for continuity and shorting.

8. Checking The Operation Of The Oxygen Sensor
Connect the oxygen sensor. Start the engine and run it until it reaches normal operating temperature.

Select "READ FUNCTIONS".
Select OXYGEN SENSOR".

The Scan Tool reading should swing between about 0.1 V and 0.9 V.

If the reading is OK, continue with point 10.

If the reading is not OK, change the oxygen sensor.







9. Checking The Wiring Harness
Check The Wiring between pin 23 of the control module and pin 4 of the oxygen sensor's 4-pin connector for continuity.

Check The Wiring for continuity and shorting.

If the lead is OK, continue with point 10.

If the lead is not OK, rectify the fault.

10. Final Check
Clear the diagnostic trouble code, drive the car on test and check whether the trouble code is generated afresh.

If the DTC is generated again, refer to Before Replacing A Control Module.

If the DTC is not generated again, the action taken to rectify the fault was correct, otherwise the fault is of intermittent nature.