Top 7 BMW Transmission Problems
The most common problems that cause a BMW transmission to malfunction include:
Low transmission fluid level - The vehicle will drive OK at first and then go into limp mode. Fluid leaking around the oil pan gasket or wire harness plug to the transmission is common on high mileage BMW vehicles.
Defective mechatronic unit - A prevalent issue is a faulty valve body also known as mechatronic units in BMW terms. The vehicle will no longer change gears and will throw warning messages on the dashbaord.
Battery too weak- low voltage is a common reason a BMW gets stuck in gear.
Faulty alternator regulator - Transmission problems are sometimes caused due to a bad voltage regulator mounted on the alternator.
Faulty MAF sensor - You may experience transmission issues such as erratic shifting between gear changes.
As you can see in this list, BMW transmission problems such as no shifting or erratic shitting are not always caused by the failure of a transmission component.
To diagnose a BMW transmission, you will need to use a BMW scan tool and read the codes from the transmission control unit.
When the engine control unit (ECU) detects a problem that can lead to transmission damage, the vehicle forces the transmission to go into limp mode to minimize further damage to the transmission.
In safe home or fail-safe mode, otherwise known as limp mode, the transmission stays in second gear and no longer shifts.
Common BMW Transmission Warnings & Symptoms
Common BMW transmission error messages and malfunctions:
Transmission Failsafe Prog. Warning signs
Transmission stuck in gear.
BMW Transmission slipping
Transmission shifts hard, not smoothly.
Transmission malfunction drive moderately message
The engine revs up, but the transmission refuses to shift.
The lag between gears such as 1st to 2nd, 2nd to 3rd
Gear ratio fault codes
Fluid leak on the ground
Shifting gears is delayed
Rough shifting between gears primarily 2nd to 3rd
Transmission service due now message on dashboard
Burning smell from under the car
If your BMW transmission is stuck in limp mode or won't shift, first check that the battery is fully charged.
Next, start with the most simple and basic steps.
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 can reset the engine control unit, and the transmission message may turn off. It doesn't always work, but it is worth a try.
If your BMW is back to shifting normal, don't assume there is nothing to worry about. There is a high chance you will experience the same transmission problem again.
To find out what is causing transmission trouble, we recommend following this guide on reading BMW fault codes. In this case, you want to read the codes from the transmission control module.
Reset BMW Transmission Adaptive Settings
If you have noticed that your BMW has erratic shifts or does not respond appropriately to the gas pedal, the problem may be incorrect shift points.
Try resetting the adaptive transmission settings. This procedure is straightforward, requires no tools, and only requires a couple of minutes.
It does not damage the transmission; it simply resets gear shift points to factory settings.
Turn on the ignition. If BMW has the Start/Stop button, press the Start button but NOT press the brake pedal.
All the dash lights will turn on. THE ENGINE SHOULD BE OFF.
Now, press the gas pedal to the floor and keep it pressed. (Ensure the kick-down switch is pressed )
Keep the gas pedal pressed for thirty seconds. (During this procedure, the engine should be off, ignition still on.)
Release the gas pedal.
Start engine and drive.
This will reset your transmission, shifting to original factory settings.
In other words, the BMW will erase the adaptive transmission shift points. BMW will monitor your driving patterns for the subsequent few driving cycles; do not drive aggressively.
This procedure does not clear any codes or reset the check engine light, but it can fix your transmission problem in some cases.
What Causes a BMW Transmission Malfunction
1. Transmission 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.
2. 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), 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, triggering 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 to 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)
3. Mechatronic - Valve Body
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 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 want 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.
Remember 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 instead 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 the gears several times to recalibrate the shift points.
4. EGS Transmission Computer Software
BMW often comes up with software updates for the automatic transmission. These updates change the shift points, which improves the shifting.
It has been reported to fix intermittent shifting problems or SAFE MODE issues in some cases.
You will need to call your BMW dealer and ask them if a software update for your particular car's transmission.
5. 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 11 volt.
If a fault code is stored in the EGS module, you will need a BMW Specific Scanner to clear the fault codes from the EGS module. First, carry diagnostic procedure to repair the problem then you will be able to remove the codes.
Low battery voltage can also cause the transmission to not go into Drive or Reverse.
6. First Gear Issues
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 the 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.
7. 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.
8. Transmission Shudders
BMW equipped with a 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.
9. Torque Converter
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.
How to Read BMW Transmission Fault Codes
The next step is to read the fault codes from the transmission module, also known as the electronic gearbox (EGS).
You will need a BMW scanner to 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 the cause of the problem.
Sometimes, you may find DSC or ABS fault code throwing 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.
This procedure will also work on BMWs that have a manual transmission.
Check Transmission Fluid Level
If a drive moderately error message pops up on your BMW, one of the first steps is to check the trans. fluid level.
If the transmission level is low, even slightly, your BMW transmission can go in limp mode to protect the transmission.
Drive your BMW for fifteen minutes to warm up the automatic transmission oil. 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.
Park the BMW on a level surface or lift it on a lift.
Let the car in park and at idle.
Raise the vehicle.
Remove the fill plug from the transmission. In some models, the drain plug can check the level. You will need to find out which transmission you have.
A minimal amount of 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 also cause shifting problems.
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 problems such as going in FailSafe or Limp mode.
A dirty transmission filter or fluid can cause shifting issues, especially in high mileage vehicles.
If you are experiencing shifting issues, consider changing the automatic transmission fluid and filter. It is essential to point out that there are many discussions and often disagreements about whether you should change the automatic fluid, especially on a sealed transmission for life.
In our experience, fresh fluid and a new transmission filter will only extend the transmission's life.
Only use the recommended fluid as noted in the owner's manual of your BMW. In most cases, you will need:
BMW Transmission Filter and Gasket Kit
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
Fluid Transfer Pump
A BMW automatic transmission holds about 9.5 qt of ATF fluid. Total system capacity includes all the oil in the transmission, oil pan, and torque converter. If you will not flush the whole system but only drain the oil pan, you need about 4.5 qt of oil.
iDrive Transmission Trouble 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 is 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
These are some of the most common error messages that come up when transmission problems are present.
Transmission Fault Codes
This is a list of common BMW transmission fault codes.
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 the power module
27EB No message (EGS 2) from the electronic transfer mission control (EGS) unit
27EC No message (EGS 1) from the 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 plausibility
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.
The problems outlined in this guide cover only BMWs with automatic transmission and do not apply to vehicles with a manual transmission.
Frequently Asked Questions
How long do BMW transmissions last?
BMW transmissions can last anywhere from 120,000 up to 200,000. This range can be affected by maintenance and also driving habits. The transmission may fail as early as 60,000 miles on an abused vehicle.
What are the signs that the transmission is going out?
Symptoms that your BMW transmission may be failing include no response when pressing the gas pedal, hesitation during accelerating, noise from under the car, or transmission refusing to change gears. In some cases, a service engine immediately or check engine light may come on.
How much does it cost to replace a BMW transmission?