Trouble Code Conditions

SPECIAL TOOLS
Volvo Scan Tool No. 998 8686, or equivalent

CONDITION
- The driving mode selector allows the driver to select from three modes: Winter (W), Economy (E) and Sport (S). The mode selector has two signal cables, MS1 and MS2, and a ground lead. Driving mode is selected by connecting one or the other, or both signal cables to ground (the signal goes low). Note that MS1 and MS2 signal cables are grounded simultaneously only when the W button is depressed.
- B=battery voltage
- G=ground (U low)
- Diagnostic trouble code (DTC) AT-124 is posted if the transmission control module (TCM) registers that the signal is low (low voltage) in both signal cables simultaneously for at least 25 seconds.

NOTE: This diagnostic trouble code (DTC) can be posted if the W button is depressed for more than 25 seconds.

SUBSTITUTE VALUE
The transmission will only operate in driving mode Economy (E).

POSSIBLE SOURCE
- Short-circuit to ground in signal cables
- Defective mode selector.
- The W button has been depressed for more than 25 seconds.

FAULT SYMPTOM(S)
- The transmission operates in driving mode E.

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