Troubleshooting BMW Transmission Problems

Vehicle:   BMW
Difficulty: ⚫⚫⚫⚫⚪
DIY Cost: $50-$2000
Est. Time: 30 min - 2 hr

A common problem many BMW owners face is the automatic transmission not shifting or erratic shifting.

When a transmission related error message displays on the iDrive, the vehicle will go in safe mode, otherwise known as a limp mode where the transmission no longer shifts. 

 

Symptoms

BMW Transmission Fault

Symptoms of BMW transmission problems:

  • Transmission stuck in gear.
  • BMW Transmission slipping
  • Transmission malfunction message
  • Transmission shifts hard, not smoothly.
  • Transmission malfunction drive moderate
  • Erratic shifting or bumping in one or more gears
  • The engine revs up and refuses to shift.
  • Transmission Failsafe Prog. Warning
  • Lag between gears such as 1st to 2nd, 2nd to 3rd
  • Gear ratio fault codes
  • Erratic shifting when changing gear

What to do?

Let's start with the most simple and basic steps.

Restart Engine

Restarting engine can sometime fix your transmission problem

If your BMW displays a transmission error message or is stuck in gear, the first thing you should do is find a safe location, turn off the engine and restart it.

Wait at least one minute before you start the car. This may reset the engine control unit, and the transmission malfunction message may turn off. It doesn't always work, but it is worth a try. 

If your BMW is back to shifting normally, don't assume there is nothing to worry about. There is a high chance that you will experience the same transmission problem again.

Get your BMW diagnosed by a mechanic or, at the minimum, read the codes yourself using a BMW Scanner and check the transmission fluid level.  

Reset Automatic Transmission

reset bmw transmission

If you have noticed that your BMW has erratic shifts or does not respond properly to the gas pedal, the problem may be incorrect shift points. 

Try resetting the adaptive settings. This procedure is straightforward, requires no tools, and only requires a couple of minutes.

It does not damage the transmission; it simply resets shift points to factory settings. 

  1. Turn on the ignition. If your BMW has Start/Stop button, press the Start button but DO NOT press the brake pedal.
  2. All the dash lights will turn on. ENGINE SHOULD BE OFF.
  3. Now, press the gas pedal to the floor and keep it pressed. (Ensure the kick-down switch is pressed )
  4. Keep the gas pedal pressed for 30 seconds. (During this procedure, the engine should be off, ignition still on.)
  5. Release the gas pedal.
  6. Start BMW and drive normally.

This will reset your transmission shifting to original factory settings.

In other words, the BMW will erase the adaptive transmission shift points. Your BMW will monitor your driving patterns for the next few driving cycles; do not drive aggressively.

Read Fault Codes from EGS 

The next step is to read the fault codes from the transmission module or also known as the electronic gearbox (EGS).

You will need a BMW scanner that can retrieve fault codes from BMW modules. With a BMW scanner, you can perform a full system scan.

Don't use a generic OBD-II scanner. If you use a generic OBD2 scanner, you will get generic fault codes such as P0720 or P0732, which don't provide enough details on what could be the cause of the problem.

Sometimes you may find there is DSC or ABS fault code that throws the transmission in limp mode. It is possible that a fault code can put your BMW automatic transmission in Fail-Safe mode even if there is nothing wrong with the transmission.

Check Transmission Fluid Level

bmw transmission fluid

If transmission malfunction, drive moderately error message pops up on your BMW. One thing that you should always check is the automatic transmission fluid level.

If the transmission level is low, even slightly, your BMW can go in limp mode to protect the transmission.

Typical signs that the transmission fluid level is low is that your BMW displays the Transmission Failsafe Prog." Warning under hard acceleration or when accelerating as you make a turn.

This happens because more transmission fluid is required during acceleration, or the fluids get pushed to one side of the trans oil pan when making a turn. As the level is low, there is no transmission fluid for the oil pump, which causes the transmission to go in FailSafe or Limp mode.

How to check BMW transmission oil

  1. Drive your BMW for 15 minutes to warm up the automatic transmission fluid. Make sure to allow the transmission to shift through all the gears. Transition fluid temperature should reach around 100 degrees F. during this driving cycle.
  2. Park your BMW on a level surface or lift it up on a lift.
  3. Let the car in park and at idle.
  4. Raise the vehicle. 
  5. Remove the fill plug from the transmission. In some models, the drain plug can be used to check the level. You will need to find out which transmission you have. 
  6. A minimal amount of transmission fluid should drain from the oil pan if the level is full.
    If the level is low, there will be no oil coming out.

Do not overfill the transmission above the recommended level, as this can cause shifting problems as well.

Change Automatic Transmission Fluid

 

A dirty transmission filter or fluid can cause shifting issues, especially on high mileage vehicles. 

If you are experiencing random shifting issues, consider changing the automatic transmission fluid and filter. It is important to point out that there are many discussions and often disagreements whether you should or should not change the automatic fluid in a BMW, especially on a transmission that is sealed for life.

In our experience, fresh fluid and a new transmission filter will only extend the transmission's life. 

Only use the recommended transmission fluid for your BMW.

  1. BMW Transmission Filter and Gasket Kit
  2. ZF Lifeguard fluid - Or as recommended in the owner's manual
    • 4.5 qt if only draining oil pan
    • 9.5 qt for full system flush
  3. Fluid Transfer Pump
  4. Torx Socket
  5. Drain Pan

A BMW automatic transmission holds about 9.5 qt of ATF fluid.

That is full system capacity, including all the oil in the transmission, oil pan, and torque converter. If you are not going to flush the whole system but only drain the oil pan, you need about 4.5 qt of oil.

Common BMW Transmission Problems

Transmission Mechatronic Sleeve

bmw mechatronic sleeve

BMW mechatronic sleeve is located on the passenger's side of the transmission near the automatic transmission.

This is where the wire harness from the Transmission Control Unit (TCU) connects the transmission.

Unplug the wire harness and inspect for oil contamination. If there is any oil, the communication between the transmission control unit and the mechatronic valve body is interrupted.

To replace or check for leaks, you will need to get your BMW up on-ramps. Remove the splash shield from under the transmission and unplug the wire harness.

Mechatronic Bridge Seal adapter

BMW Mechatronic bridge seal adapter

A BMW may display a Transmission Fault warning message on the iDrive screen due to a cracked adapter BMW Mechatronic adapter (Part #: 0501 215 783 01), also known as trans seal grommet, for the mechatronic valve body.

Under normal conditions, the grommet allows the fluid to flow from the transmission to the mechatronic valve body without any fluid loss.

This allows transmission fluid to make it to the mechatronic without any pressure loss, allowing normal gear shifting.

The grommet or the plastic adapter can crack over time, which allows the fluid to leak at this port. When this happens, the fluid pressure at the mechatronic valve body is reduced.

Because the fluid pressure is reduced, the valve body's solenoids cannot open and close properly, which triggers the transmission fault or erratic shifting.

This part is easy to replace and comes in plastic or aluminum.

The OEM part sold at BMW is usually plastic, but upgraded aluminum adapters can be purchased online and last longer than the plastic version.

This problem is common on these BMW transmissions: 6HP26, 6HP28, and 6HP32. Aluminum Part Number SFC-MA-001 is available.

Another indicator that this part is broken is that you will typically get the Transmission Fault popup as you move the shifter from drive to reverse. 

Most affected by this problem:

  • 2001 2008 BMW E65/E66 7 Series
  • 2004 2006 BMW E53 X5 V8
  • 2003 2010 BMW E60 5 Series
  • 2005 2011 BMW E90 3 Series
  • 2003 2010 BMW E63/E64 6 Series
  • 2007 2013 BMW E70 X5 Except 4.0d
  • 2008 2012 BMW F01/02 7 Series (except 760i/Li and Hybrid 7)

Mechatronic - Valve Body

BMW Mechatronic

If you read the codes, you may get fault codes related to the valve body, also known as the BMW mechatronic.

BMW ZF mechatronics is notorious for problems with 2nd to 1st gear downshifts or shift flares during the upshift. These harsh upshifts and downshifts are often due to a TTC clutch failure, overheating, damaged solenoid, worn selenoid springs, and other problems with the mechatronic unit.

If you checked everything above but are still having problems with your BMW transmission, the cause most likely is the mechatronic unit. If you are looking to save money, you can consider replacing only the solenoids in the mechatronics unit/valve body.

If you decide to replace the solenoids yourself, remember to change the foam strip between the solenoid terminals and connectors.

If you want a unit that has already been remanufactured and tested, you can buy a remanufactured BMW Mechatronic unit online. If you have some basic DIY skills, you can replace the mechatronic unit on a BMW.

Keep in mind that the unit may need to be codded to match your VIN. Before you purchase a replacement mechatronic unit, check with the seller or BMW dealer if programming or coding is required for your model.

As seen in the following video, it is possible to replace BMW mechatronic yourself.

If you would rather let a mechanic do the work, this repair can cost anywhere from $1500 to $3500.

If you decide to have the dealer replace the mechatronic on your BMW, it will usually cost anywhere between $2100 and $3500.

It is recommended to reset the transmission module after the Mechatronic replacement. Drive the vehicle around for about 15-20 minutes, making sure transmission cycles through all the gears several times to recalibrate the shift points.

EGS Transmission Software 

BMW often comes up with software updates for the automatic transmission. These updates change the shift points, which improves the shifting.

In some cases, it has been reported to fix erratic shifting problems or SAFE MODE issues.

You will need to call your BMW dealer and ask them if there is a software update for your particular car's transmission. 

Transmission Stuck FailSafe Mode due to Weak Battery

We have seen cases where the BMW transmission will get stuck in second or third gear and will not come out of failsafe mode even if you restart the car.

In one case, this problem was caused by a dead battery that stored hard codes.

Even though the BMW battery was replaced, the car remained in Failsafe mode. Typically a BMW will go into failsafe mode if the voltage is under 9 volt.

If a hard code is stored in the EGS module, you will need a BMW Specific Scanner to clear the fault codes from the EGS module.

Low battery voltage can also cause the transmission to not go into Drive or Reverse.

1st Gear Issue

Often the transmission issue may be due to a problem with the first gear only. To verify that the problem is with the first gear, set your BMW transmission in Winter mode, which forces the transmission to start in second gear.

If your BMW shifts normally when in winter mode, that means there is an issue with the first gear. Keep the transmission in winter mode until you get your BMW transmission repaired.

Stuck In Park

If your BMW is stuck in the park and the shifter won't come out, the problem could also be the brake light switch or park solenoid.

Transmission Shudders

BMW that are equipped with twin-turbo may experience shuddering symptoms, especially during a long trip. To verify that this is the issue, it is recommended that you stop your car and let it cool down.

If transmission shuddering symptoms go away when the engine cools down, the problem may be caused by the twin turbos. A check engine light may also come on. Symptoms often happened between 50-70 mph.

Another reason why you may experience transmission shudder is due to issues with the torque converter. This is often because the torque converter locks up, is wearing out, and not locking the torque converters.

BMW transmission shudder may also be caused due to spark plug or fuel injector problems. If the check engine light is on, make sure to scan the ECU codes so that you can get a better idea of why the transmission shuddering is happening.

iDrive Transmission Messages

This is a list of common BMW transmission messages. These messages vary between models, but they all point to problems with BMW transmission.

  • Transmission Malfunction - Functionality or display of the gear selector position may malfunction. Gearbox position P may not be available. Set parking brake when completely stopped. Engine start may be possible with a delay.
  • Trans. Malfunction - Drive moderately. Continued driving possible. Reduced acceleration. Have the system checked by the nearest BMW center
  • Transmission Malfunction. Limited gear selections are possible. COntinued driving is possible./ Drive moderately. Have the system checked by your nearest BMW center.
  • Transmission Faulty - Transmission position P possibly not available. Operate parking brake when car stationery. Please contact the BMW service department.
  • Trans. Failsafe Programming

BMW Transmission Fault Codes

This is a list of common BMW transmission fault codes.

 Show   the  
  • 578E - EGS Gearbox oil wear
  • CF17 No message from JBBF. Vehicle mode receiver DKG/EGS transmitter DSC/DME
  • 5140 is No CAN message from DME
  • 4F8F - EGS: Ratio monitoring, gearshift 3-2
  • 5149 is No CAN message from power module
  • 27EB No message (EGS 2) from electronic transfer mission control (EGS) unit
  • 27EC No message (EGS 1) from electronic transmission control (EGS) unit
  • 299A CAN fault management, electronic transmission control (EGS)
  • 4f81 - Gear ratio monitoring, Clutch A
  • cf17 - Calibration between ISTA/D and ISTA/P missing
  • 507B or 507C - Parking gear sensor implausible signal
  • 507D - Parking gear incorrectly disengaged
  • 4f89 - ratio monitoring gearshift incorrect
  • 4f92 - EGS ratio monitoring,clutch A-C
  • 4f8d - Ratio monitoring, gearshift 5-4 – plau sibility
  • 37 - Voltage Low
  • 4f85 - 4F85 RATIO MONITORING CLUTCH E
  • 4f8a - RATIO MONITORING.GEAR SHIFT 4-5 GEAR
  • 5088 - Sensors, transmission switch L1-L4
  • 507C - Parking gear sensors implausible
  • 507B PARKING GEAR SENSOR IMPLAUSIBLE
  • 4F84 RATIO MONITORING CLUTCH D
  • 4F97 RATIO MONITORING CLUTCH "B"-D
  • 4F83 RATIO MONITORING CLUTCH C

This list does not include all BMW EGS fault codes. A BMW scanner is required to read and clear these BMW codes.

By YOUCANIC Automotive Experts
Nov 2020

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