Diagnostic Trouble Code (DTC) Information

Condition







The transmission speed signal is transmitted by a sensor on the transmission. The transmission control module (TCM) uses the signal to determine the input shaft speed after the torque converter. This signal is used to compare the transmission speed with vehicle speed. The transmission control module (TCM) uses this comparison to calculate the gear-shift timing. Engine speed (RPM) and vehicle speed data affects the adjustment of the system pressure, lock-up function control and engine torque reduction. The result is smooth gear-shifting. Diagnostic trouble code (DTC) TCM-0089 is stored if the control module registers that the signal is too low when vehicle speed is above approximately 25 km/h.

Substitute value
- The transmission control module (TCM) "Emergency mode I" program has been initiated.

Possible source
- Contact resistance in the terminals.
- Short-circuit to ground in the signal cable.
- Defective speed sensor.

Fault symptom[s]
- The warning lamp for the automatic transmission flashes.
- No lock-up function.
- Harsh gear shifting.

HINT: Harsh gear shifting can be caused by:
- No reduction of the line pressure when shifting.
- No reduction of line pressure when moving the gear selector between positions P-R, N-R and N-D.
- No request for torque limiting to the engine control module (ECM) when shifting.