Diagnostic Trouble Code (DTC) Information

Diagnostic trouble code (DTC) information
998 8686 Replaced by 9511532 998 8686 Replaced By 9511532
Condition




Shift solenoids S2 and S1 operate in tandem to control gear-shifting. The solenoids are controlled by amplifiers in the transmission control module (TCM). The transmission control module (TCM) opens the amplifiers 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 stored 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 stored 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, N, D, 3 or L. Solenoid S1 cannot then be activated or is activated continuously (depending on the fault cause).

Substitute value

Transmission control module (TCM) "Limp home" program 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 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 and 4th gear (D position), 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 line pressure solenoid STH control, resulting in constant maximum line pressure. This leads to harsher shifting and gear meshing.
- No lock-up function.
- No reverse gear (depending on fault cause).