Diagnostic Trouble Code (DTC) Information TCM-0023
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 and the vehicle speed. The transmission control module (TCM) uses this comparison to calculate the gear-shift timing.
The information about engine speed (RPM) and road speed is also used when adjusting system pressure (for lock-up function control) and for torque reduction when shifting gear. The result is smooth gear-shifting.
The information is also used to control the lock-up function. The transmission control module (TCM) also calculates and compares the input and output speeds from the transmission and the engine speed (RPM) for diagnostics.
The diagnostic trouble code (DTC) is stored if the transmission control module (TCM) registers that the signal from the engine speed (RPM) sensor is missing.
The diagnostic trouble code (DTC) can be diagnosed at speeds above approximately 70 km/h and when the temperature of the transmission fluid is above 20°C.
Substitute Value
- Emergency program Emergency mode 1 in the transmission control module (TCM) has been initiated.
Possible Source
- Contact resistance in the terminals
- The transmission speed sensor does not function
- Internal fault in the transmission control module (TCM).
Fault symptom[s]
- Malfunction indicator lamp (MIL) lit
- General warning lamp lit
- No lock-up function
- Harsh gear shifting
- No shifting.