DME 7.8
P0132
02 Sensor Circuit High Voltage
NOTE: The diagnosis for this fault is different for models with turbo engines and models with naturally-aspirated engines.
Diagnosis/troubleshooting - all turbo models
NOTE: The DTC here also covers the possibility of a mechanical malfunction in the valve drive.
Diagnostic conditions
NOTE: It takes a very long time (several driving cycles) to detect a fault.
Possible cause of fault
- Valve lift fault
- False air on the oxygen sensor after catalytic converter
- Oxygen sensor faulty
NOTE:
- As this fault can be caused by a faulty flat-base tappet, a system test for a small lift has to be performed initially. The fault can occur sporadically; the test should therefore be performed at least three times when the engine is at operating temperature.
- First indication of a valve lift fault can be provided by the adaptation values at idle speed (RKAT) and in the lower part load (FRAU) if they differ by more than 10 %.
Perform system test for small lift
WARNING: The test is carried out while driving. Get a second person to operate the Porsche System Tester 2.
During the system test for small lift, the valves remain at small lift, regardless of the type of driving. Faulty switching conditions can be detected by rough running, just like with misfire detection.
Several cylinders may be stored as faulty, although only one valve on one cylinder is faulty.
In order to ensure that the fault is repaired, the flat-base tappets of the inlet valves of the entire cylinder bank should be replaced if a fault occurs.
A faulty flat-base tappet can be detected because the oxygen sensor FR for this cylinder bank enriches the mixture (F(R) > 1) during acceleration with wide-open throttle - see drawing below. Difference from the other oxygen sensor > approx, 15 %. In the case of a fault, the flat-base tappets of the inlet valves for the entire cylinder bank must be replaced.
1 - Select System test.
2 - Select 'Request small lift'.
If "Valve lift diagnosis not ready" appears, a fault may have been stored.
1. Erase the fault memory.
3 - Activate the system test with the [F8] key immediately before acceleration with wide-open throttle.
The message "Drive link active" then appears.
NOTE: If 'Request small lift' appears, the valves remain at small lift, i.e. the performance is reduced dramatically.
4 - Perform acceleration with wide-open throttle in 2nd gear, until "Valve lift diagnosis completed" (max. 4000 rpm) appears.
At speeds above 4000 rpm, misfires may be stored Erase the fault memory and repeat the test.
NOTE:
- If a fault is detected, it is only recorded in the fault memory after 6,000 ignitions (at idling speed approx. 3 minutes waiting time).
- It is important to observe the oxygen sensors during acceleration with wide-open throttle or to record their behaviour with the data logger.
Diagnosis/troubleshooting
NOTE: Do not use contact spray on the oxygen sensor plug connections as this may cause irreparable damage to the wiring (contamination of the oxygen sensor via the reference air channel).
Diagnosis/troubleshooting - all naturally-aspirated models
NOTE: The DTC only covers electrical faults here.
Diagnostic conditions
- Battery positive voltage between 10 V and 16 V
- Exhaust temperature less than 800°C
- Oxygen sensor heating switched on for at least 120 seconds
NOTE: DTC PO132 is stored by the DME control module when the sensor voltage is continuously above 1.5 V for more than 5 seconds.
Possible cause of fault
- Short circuit to B+ in signal wire
- Oxygen sensor faulty
- Control module faulty
Affected pins
DME control module connector II, pin 9 and oxygen sensor jack, bank 1, pin 3
DME control module connector II, pin 15 and oxygen sensor jack, bank 1, pin 4
Diagnosis/troubleshooting
NOTE: Do not use contact spray on the oxygen sensor plug connections as this may cause irreparable damage to the wiring (contamination of the oxygen sensor via the reference air channel).
Part 1:
Part 2:
