System G100, G101, G102, G110

Fault Code 20

20, Transmission oil temperature sensor/starter interlock contact
The ATF transmission oil temperature sensor and the starter interlock contact are switched in series.

NOTE:
- The ATF transmission oil temperature sensor and the starter interlock contact are housed in the electrical part of the hydraulic control unit.
- If the ATF transmission oil temperature sensor or the starter interlock contact is faulty, the complete electrical part of the hydraulic control unit must be replaced.
- The fault can only be deleted in selector lever position 'D' or 'R'.
- The ATF temperature is accepted at the last measured value as a substitute value and correspondingly displayed as such in the actual values.

Diagnostic conditions
- Ignition on

Possible cause of fault
- ATF temperature [<] -49 °C or [>] 175 °C
- Short circuit to B+/ground/between wires or open circuit
- ATF transmission oil temperature sensor faulty
- Starter interlock faulty
- Tiptronic control unit faulty

Affected pins
Plug A: pin 33 and pin 34

Diagnosis/troubleshooting

Part 1:

Part 2: