Diagnostic Trouble Code (DTC) Information

DTC information

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 transmission control module (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 transmission control module (TCM) registers an open-circuit or short-circuit to supply voltage in the solenoid S1 circuit when the solenoid should not be activated. Diagnostic trouble code (DTC) AT-122 is also posted if the transmission control module (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 transmission control module (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 transmission control module (TCM).

Fault symptom[s]
- The combined instrument panel warning lamp flashes
- Deterioration in performance because the transmission control module (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 diagnostic trouble code (DTC) when the transmission sends a malfunction indicator lamp (MIL) request. Erase this diagnostic trouble code (DTC) in the Motronic engine control module (ECM) when the transmission fault has been repaired.