Possible reasons for the disappearance of all automatic transmission gears on a Mitsubishi:
Electrical problems:
*Faulty Engine Control Module (ECM) or Transmission Control Module (TCM)
* Damaged or loose wiring connecting the transmission to the ECM/TCM
*Dead battery
* Faulty gear selector
Mechanical problems:
*Low or dirty transmission fluid
* Worn or damaged friction plates
* Stuck shift valve
* Faulty torque converter
* Transmission shaft failure
Software errors:
*Errors in ECM/TCM software
*Incompatible software updates
Other possible reasons:
*Using inappropriate transmission fluid
* Excessive load on the transmission
* Wear or damage to the differential box
What to do if all automatic transmission gears on a Mitsubishi are missing:
1. Check the level and condition of the transmission fluid. The liquid should be at the appropriate level and reddish in color. If it is brown or black, or has a burning smell, it needs to be replaced.
2. Check the battery. Make sure the battery has sufficient voltage and is connected securely.
3. Check electrical connections. Inspect all wiring connecting the transmission to the ECM/TCM for damage or looseness.
4. Perform diagnostics using the scanner. Connect an OBD II scanner to the vehicle to check for transmission-related trouble codes.
5. Seek professional help. If you cannot fix the problem yourself, contact a qualified mechanic for help.
Warning: Do not attempt to repair the transmission yourself unless you have the proper knowledge and experience. A faulty transmission can lead to loss of vehicle control and serious accidents.