Symptoms of a faulty automatic transmission control unit:
General symptoms:
* Strange gear shift behavior (hard shifts, slipping, stuck gears)
*Transmission fault codes read using scan tool
* Gear position indicator failure (does not show current gear or shows incorrect information)
Specific to the Symptome model:
* Inconsistent or inconsistent readings from the input and output shaft sensors
* Faulty gear shift solenoids
* Incorrect transmission fluid pressure management
* Faults in the engine control system (ECU) related to automatic transmission
Additional signs requiring further diagnosis:
*Check Engine light is on or flashing
*Loss of engine power
* Unstable engine speed at idle
*Leaking or contaminated transmission fluid
Methods for checking the serviceability of the automatic transmission control unit:
* Reading Trouble Codes: Use a diagnostic scan tool to read automatic transmission and engine trouble codes. The codes will help determine whether there is a malfunction in the automatic transmission control unit.
* Checking the input and output signals of sensors: Check the correct operation of automatic transmission sensors, such as input and output shaft speed sensors, gear shift position sensors, etc.
*Checking Shift Solenoids: Use an oscilloscope or special testing tool to check the shift solenoids.
*Transmission Fluid Pressure Measurement: Measure the transmission fluid pressure during various driving conditions. Incorrect pressure may indicate a malfunction of the automatic transmission control unit.
* Replacement of the automatic transmission control unit: If other testing methods do not reveal any problems, the automatic transmission control unit may need to be replaced.
Note:
Diagnosing a faulty automatic transmission control unit can be complex and requires special tools and knowledge. It is recommended that you contact a qualified mechanic for proper diagnosis and repair.