Trouble Code Conditions

CONDITION
Shift solenoids S2 and S1 operate in tandem to control gear-shifting. The solenoids are controlled by the amplifier in the Transmission Control Module (TCM). The TCM opens the amplifier to activate the solenoids sending a voltage through the circuit. Solenoid S1 is activated on 2nd and 3rd gears. Diagnostic Trouble Code (DTC) AT-122 is posted if the TCM registers an open-circuit or short-circuit to supply voltage in the solenoid S1 circuit when the solenoid should not be activated. DTC AT-122 is also posted if the TCM registers a short circuit in the solenoid S1 amplifier when it should not be activated, and the gear selector is in positions P. R. D, D, 3 or L. Solenoid S1 cannot then be activated or is activated continuously (depending on the fault).

SUBSTITUTE VALUE
- The TCM limp-home program has been initiated.

POSSIBLE SOURCE
- Open-circuit in signal cable
- Short-circuit to supply voltage in the signal cable.
- Open-circuit in power ground
- Defective solenoid
- Contact resistance in terminals
- Fault in TCM.

FAULT SYMPTOM(S)
- The combined instrument panel warning lamp flashes
- Deterioration in performance because the TCM prevents activation of the solenoids, this stops gear-shifting. The transmission operates only in 3rd gear in positions 3 and L, 4th gear in position D and reverse in position R. Shifting can only be carried out manually between 3rd, 4th, and reverse gear. If there is a short-circuit to supply voltage in the solenoid circuit the transmission will probably only operate in 3rd gear.
- No system pressure solenoid STH control resulting in constant maximum system pressure leading to harsher shifting and gear meshing.
- No lock-up function.
- No reverse gear (depending on fault).

NOTE:
- The Motronic 4.4 engine control module (ECM) posts a DTC when the transmission sends a malfunction indicator lamp (MIL) request.
- Erase this DTC in the Motronic ECM when the transmission fault has been repaired.

TESTING PROCEDURE
- Start fault-tracing at Fault In Solenoid Circuit. Fault In Solenoid Circuit