Trouble Code Conditions

SPECIAL TOOLS
Test box tool No. 981 3190, or equivalent
Volvo scan tool No. 998 8686, or equivalent

CONDITION
The Transmission Control Module (TCM) uses the kickdown switch signal to control functions such as downshifting during rapid acceleration. The kick-down switch closes when the outer sleeve of the accelerator cable is pressed against the switch (when the Accelerator Pedal (AP) is fully depressed). Diagnostic Trouble Code (DTC) AT-143 is posted if the TCM registers a short-circuit to ground in the kick-down switch circuit when the throttle opening is less than 85%.

CAUTION: DTC AT-143 is posted when the kick-down switch is closed if the Throttle Position (TP) sensor signal is too low at Wide Open Throttle (WOT) (less than 85%).

SUBSTITUTE VALUE
No substitution value

POSSIBLE SOURCE
- Short-circuit to ground in signal cable
- Defective kick-down switch
- Faulty throttle position (TP) sensor signal
- Transmission control module (TCM) replaced but throttle position (TP) sensor signal not adapted.

FAULT SYMPTOM(S)
- No kick-down function.

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