4F89 EGS : Ratio Monitoring, Gearshift 3-4

In BMW E-series E70,E80,E90, fault code 4F89 EGS : Ratio Monitoring, Gearshift 3-4 is related to the problem with automatic transmission gear box. BMW use 5speed or 6speed automatic transmission gear to make a comfort driving. whenever problem occurs in gear shifting this kind of fault code store in automatic transmission control module. this type of problem can be caused either by faulty transmission mechatronic solenoids or internal clutch wear. worn out multiclutch can lead to no shift of gear after 3rd gear.

Symptoms of 4F89 EGS : Ratio Monitoring, Gearshift 3-4 ;

Most of the time this kind of problem occurs while driving at high speed. while driving at low speed you feel no problem at all. but after certain kilometer at high high speed you feel jerking in the gear box. there will be no gear shift after 3 gear, but you will notice high rev at cluster. gear will stuck at 3rd gear position, there will be no changes in that either up or down. transmission will be lock at 3rd gear position without going up or down. Then pop up of warning light will appear on cluster or navigation screen. but if you will turn off the car for some time and wait. then again if you will start the vehicle everything will be fine as it was before.

Causes of 4F89 EGS : Ratio Monitoring, Gearshift 3-4 :

  • Faulty mechatronic solenoid valves.
  • Worn out multi clutch.
  • Reprograming of gear box.
  • Low transmission oil level.
  • electrical problem out of the gear box.
  • mechanical problem inside gearbox.

Solution of 4F89 EGS : Ratio Monitoring, Gearshift 3-4 :

  • Replace faulty mechatronic solenoids.
  • Repair mechanical problem in gear box.
  • Replace worn out multiclutch.
  • Change oil of transmission at certain kilometer.
  • Repair electrical fault if any.
  • Reprogram automatic transmission.

How to trouble shoot fault code 4F89 ;

there might be so many different causes behind this problem :

STEP#1: Check the oil level in automatic transmission gear box for its require level and also quality of oil. check the driven kilometer if it is above 60-80K kilometer it is require to change. As most of the automatic transmission making company give advice to change the transmission oil after 60-80K kilometer. check the quality of oil if it is require then change the oil with the manufacturer recommended transmission oil. after changing oil perform adaptation of gear with the help of BMW ISTA software that might be solve the problem.

STEP#2: This can be happen because of some electrical problem in the automatic transmission or out of the automatic transmission at control module or in the wiring harness. check the problem out of the gear box, if found then solve it. which will help you to solve the problem quickly, but if it is inside the gear box. It might let you to do hard wok with gear box to solve the problem.

STEP#3: The problem can be inside the gear box, either faulty mechatronic solenoid, worn out clutch or faulty multiclutch. if anyone of this things are not good it will cost to much to repair as all parts of gear are costly to repair. Replacing of transmission gear box with the use gear box is better than repairing or replacing the mechatronic solenoid, worn out clutch, faulty multiclutch. Change the gear box unit as well as flush the transmission oil, change transmission oil and oil filter. Perform adaptation of gear box after changing the gear, it will calibrate its clutch accordingly.

How risky it is drive with fault code 4F89 :

Driving with the fault code 4F89 is not highly risky as it will only not allow to change the gear after 3rd or 4th. gear will be lock after 3rd or 4th gear it will not move either up or down. at low speed no problem can be found but after a certain kilometer driving at high speed jerking will feel in the gear box. that’s why it will only stop you to drive at high speed.

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