Trouble Code Conditions

Special Tools
- 981 3190
- 998 8686

Trouble Code Conditions
- 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 transmission control module opens the amplifier to activate the solenoids sending a voltage through the circuit. Solenoid S1 is activated on reverse, 1st and 2nd gears. Diagnostic trouble code (DTC) AT-122 is stored if the transmission control module 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 stored if the transmission control module registers a short-circuit in the solenoid S1 amplifier when it should not be activated, vehicle speed is over 25 km/h (16 mph) and the gear selector is in D, or 3 in 3rd and 4th gears. Solenoid S1 cannot then be activated or is activated continuously (depending on the fault).

Substitute value(s)
- The transmission control module limp-home program has been initiated.

Possible source(s)
- 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 transmission control module.

Fault symptom(s)
- The combined instrument panel warning lamp flashes.
- Deterioration in performance because the transmission control module prevents activation of the solenoids, this stops gear-shifting. The transmission only operates 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 1st gear.
- No system pressure solenoid STH control resulting in constant maximum system pressure leading to harsher shifting and gear meshing.
- No lock-up function.

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

- Start fault-tracing. Fault In Solenoid Circuit