Diagnostic trouble code (DTC) information
Condition
The automatic transmission control module (TCM) receives speed signals from the ABS control module and from the speed sensor on the transmission. The transmission control module (TCM) uses the signals to select the correct gear. The control module derives and compares the speed signal from the ABS system with the transmission speed and the engine speed (RPM) at the transmission. Diagnostic trouble code (DTC) TCM-0020 is stored if the control module registers that the speed signal from the ABS system does not correspond with the transmission speed or the engine speed (RPM).
Substitute Value
- None.
Possible Source
- Contact resistance in the terminals.
- Open-circuit, short-circuit to ground or short-circuit to supply voltage in the power supply.
- Open-circuit, short-circuit to ground or short-circuit to supply voltage in the signal cable.
- Defective speed sensor.
Fault symptom[s]
- General orange warning lamp lit.
- Malfunction indicator lamp (MIL) lit.
- 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 the 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.