T_RET_MALFUNCT_ADC_ABOVE; Retarder oil temperature sensor; Voltage above upper limit
â–¶ How to fix
Switch off ignition; Disconnect electronics; Connect transmission test cable; Measure resistance of the temperature sensor (pin18) against the sensor ground terminal (pin 17); Nominal value: 20°C ->approx. 120 kohm, 80°C ->approx. 12 kohm, 140°C ->approx. 2 kohm; For additional values, see temperature sensor data sheet. Check cable TCU -> transmission If you find deviations from nominal value, check wiring and component.
What you'll see
No driver-visible symptom recorded.
System reaction
Reduced retarder torque;
Diagnostic depth
Detection
ADC value cold > 1000, corresponds to < 23°C and T_Sump > 50°C; Normal mode
Possible cause
Reduced retarder braking performance;