Trouble Code Conditions

SPECIAL TOOLS
Volvo scan tool No. 998 8686, or equivalent

CONDITION
The oil temperature sensor sends a signal to the transmission control module (TCM) which is used for functions such as temperature controlled lock-up and initiating high-temperature programs. The sensor has an NTC (negative temperature coefficient) resistor. The signal decreases in proportion to increasing oil temperature. Diagnostic trouble code (DTC) AT-142 is posted if the TCM receives a signal from the oil temperature sensor corresponding to a temperature below -10°C when the engine is started and that signal has not changed when the engine has been running for 10 minutes.

SUBSTITUTE VALUE
No substitution value

POSSIBLE SOURCE
- Open-circuit in signal cable or ground lead
- Short-circuit to supply voltage in the signal cable.
- Defective oil temperature sensor.
- Contact resistance in terminals

FAULT SYMPTOM(S)
- No fault symptoms.

TESTING PROCEDURE
- Start fault-tracing at Signal Too High. Signal Too High