P2850 Shift Fork 4 Uncommanded Movement

This fault can be found in skoda, vw or audi like vehicle which are with automatic transmission gear box. Fault code P2850 Shift Fork 4 will store in the controller of transmission control module .When the transmission control module detect the problem in the TCM to shift the fork 4 which is Reverse gear in automatic transmission gear. this fault code can be store because of the hard shift or no sift of fork 4. In this situation the car will not move in reverse gear as the shift fork or reverse gear in not working.

This can be happen because of a faulty mechatronic or it can be cause because of bad quality of oil in transmission. oil of transmission should change at the interval of time according to the manufacturer. bad quality of oil also effects in the shifting of fork or gear in automatic transmission.Basic setting of transmission control module can solve this problem.

How Risky It Is :

Driving vehicle with this fault code store in the engine control module or transmission control module is not possible. As this fault code store in engine control module when there is a problem is monitor in the automatic transmission gear box. when TCM detect problem in shifting of gear, it store fault code in the system. this can be happen because of several reason just like low pressure of gear oil, faulty oil line in mechatronic, faulty mechatronic or there is possibility of electrical problem out side the gear box. sometime break wire of mechatronic send wrong signal to the transmission control module.

But in the most of the cases it has been seen that when this problem occurs in the vehicle, there is always a problem with the quality of gear oil. changing transmission oil at the appropriate time is require as it quality can not be bad after certain kilometer. a bad quality oil in transmission can lead to problem in changing gears.

Cause of P2850 :

  • Faulty mechatronic.
  • low level of oil or bad quality of oil in transmission.
  • faulty shift fork.
  • broken shift fork.
  • stuck shift fork.

Symptoms of P2850 :

  • Car will not shift in reverse gear or and other gear.
  • shifting of the transmission will become so hard.
  • gears will make noise.
  • transmission light will illuminate on cluster meter.
  • fault code will store in the transmission control module.

Solution of P2850 :

  • Change the oil in transmission gear and flush it if require.
  • check the mechatronic for any damage or worn out at plate.
  • Perform basic setting of transmission gear.
  • replace transmission control module.

Special note :

Before replacing any part like mechatronic, shift fork or any think in the transmission gear box. check all other thing which are related to this problem and can lead this type of problem in the vehicle. check all the wiring harness, fuses, and can wiring connected to the mechatronic of the gear box. if all the power supply, ground, fuses and can wiring harness is good.

then go to check the oil of the transmission gear if the quality of the oil is not meat the condition than first of all change the gear oil. at the time of checking the gear oil check the oil for any fine metal particles present in that or not. if fine metal particle are found in the gear oil it may be possible that the shift fork may be broke. if metal particles are not present in the gear oil than change the gear oil .

After changing the oil perform basic setting of gear by its scanner. it will take some time but will be ok after performing basic setting. After performing basic setting if it does not work. then go for further procedure to program the transmission control module. and if require then only change the mechatronic of transmission.

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