Yes, after replacing an automatic transmission, it is usually necessary to reprogram the vehicle’s ECU (electronic control unit).
The reason for this is that the ECU controls the interaction between the automatic transmission and other vehicle systems such as the engine, sensors and brakes. When replacing an automatic transmission, the new control unit must be programmed with the appropriate parameters and calibrations to ensure proper operation of the entire system.
ECU firmware after replacing an automatic transmission may include:
* Uploading updated software to the ECU
* Calibration of gear shift parameters
* Adjustment of torque converter locking points
* Connecting new sensors or components installed with a new automatic transmission