Diagnostic Trouble Code (DTC) Information

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




Solenoid S1 operates in tandem with solenoid S2 to control gear-shifting. Solenoid S1 operates when it receives a signal from the transmission control module (TCM) and is activated in 2nd and 3rd gears. Diagnostic trouble code (DTC) AT-121 is stored if the transmission control module (TCM) registers a short-circuit to ground in the solenoid S1 circuit when the solenoid should be activated. Solenoid S1 cannot then be activated.

Substitute value
Transmission control module (TCM) "Limp home" program initiated.

Possible source
- Short-circuit to ground in signal cable.
- Defective solenoid.

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.
- No line pressure solenoid STH control resulting in constant maximum line pressure. This leads to harsher shifting and gear meshing.
- No lock-up function.