Electrical diagram of the automatic transmission control unit
Designations:
*ECM: Engine Control Module
*TCM: Transmission Control Module
* VSS: Vehicle Speed Sensor
*TRS: Throttle Position Sensor
*NS: Neutral Position Sensor
*TSS: Shift Position Sensor
* ISP: Parking status switch
*FL: Reversing lamp
* TR: Reverse switch
*IGN: Ignition switch
* PWR: Power supply
Electrical diagram:
“`
+——————————–+
| |
| |
| |
| |
|——–ECM——–TCM———-|
| | |
| TSS/NS/VSS | TR/FL/ISP |
| | |
+————————+———-+
| |
| |
| |
| |
+————-+ +———+
| ECM Power | | TCM Power |
+————-+ +———+
“`
Functions:
* The TCM receives signals from various sensors including VSS, NS, TSS, ISP, FL and TR.
* The TCM uses these signals to control automatic transmission operation, including gear shifting, torque converter lock-up, and hydraulic pressure control.
* The TCM communicates with the ECM to exchange information about engine and transmission performance.
* The ECM provides power and other necessary signals to the TCM.
Troubleshooting:
* This electrical diagram can help in diagnosing automatic transmission faults.
* Check all connections and signals to ensure the transmission control module is receiving the necessary data to operate properly.
* If problems occur with shifting, torque converter lock-up, or other aspects of the automatic transmission, the diagram can help determine the possible source of the problem.