BMW Drivetrain: Faults and Solutions

BMW vehicles may display a Transmission Fault, Drive Moderately error message on the dashboard if there is a problem with the engine or transmission.

This message usually appears when accelerating hard or trying to overtake a vehicle. It can also appear in cold weather or even under normal conditions. To diagnose the problem, you can use a BMW scanner which will allow you to read the Digital Engine Electronics (DME) module fault codes.

 

What does a transmission failure mean?

The BMW Transmission Malfunction Error message means that the Engine Control Module (DME) has detected a problem with your engine. Maximum torque is no longer available. This issue can be caused by several issues, see the Common Causes section below.

In most cases, your BMW will lose power, the engine will shake or stall, and may even go into emergency mode (the transmission won't shift anymore). This is a common BMW problem that affects many models especially 328i, 335i, 535i, X3, X5.

symptoms

Although the symptoms may vary depending on the problem that caused the error, this is what most BMW owners usually notice.

• Transfer error message on iDrive screen
• The car starts to shake
• Check if the engine is running
• Vehicle stalls/stalls when idling or shifting gears (D)
• exhaust smoke
• car idling
• Gearbox stuck in gear
• Transmission failure when trying to drive on a highway
• Transmission failure and car won't start

What should I do?

Make sure the engine does not overheat. Make sure the oil level gauge is NOT lit. Please continue to drive carefully. Keep driving, but don't drive too hard. Be light on the gas pedal.

If the engine is shaking and engine power is reduced or the vehicle is idling, it is not recommended to drive a shorter distance.

Restart engine

Find a safe place to park your BMW. Switch off the ignition and remove the key. Wait at least 5 minutes, then restart the car. In many cases, this temporarily resets the failed BMW transmission and allows you to continue driving.

Check the engine

• Check engine oil level.
• Monitor engine temperature.
• Do not overheat the engine. In this case, stop and turn off the engine.

Reading codes

Read fault codes as soon as possible with a scanner such as Foxwell for BMW or Carly. The codes stored in the DME will tell you why the transmission failed error occurred. To do this, you will need a special BMW diagnostic scanner. Regular OBD2 scanners are of little help as they cannot read manufacturer error codes.

Follow this guide to learn how to read BMW fault codes yourself.

Do not ignore the BMW transmission malfunction warning. Contact BMW for service as soon as possible. Even if the transmission error goes away, you still need to have your BMW diagnosed as there is a good chance that the problem will return.

Common causes

BMW transmission failure is often caused by engine misfiring. Most likely your issue is related to one of the following issues. We highly recommend having your BMW diagnosed by a mechanic, or at least reading the fault codes yourself, before proceeding to replace any parts.

Spark plug

Worn spark plugs are often the cause of transmission failure in BMW vehicles. When replacing spark plugs, replace them all at the same time.

Ignition coils

A bad ignition coil can cause an engine error and bmw transmission failure error message in iDrive.

If you have a misfire in a particular cylinder, the ignition coil for that cylinder is most likely defective. Let's say the misfire is in cylinder 1. Swap the ignition coils for cylinder 1 and cylinder 2. Clear the codes with an OBD-II scanner. Run the vehicle until the check engine light comes on. If the code reports cylinder 2 misfire (P0302), this indicates a bad ignition coil.

High pressure fuel pump

A BMW transmission failure may be caused by the fuel pump not producing the required fuel pressure. Especially if an error message appears when accelerating. The fuel pump may not be able to build up enough pressure, especially when the engine requires higher pressure.

Catalytic Conversion

A BMW transmission error message can also be caused by a clogged catalytic converter. This most commonly occurs on a high mileage vehicle when the catalytic converter starts to clog and restrict exhaust gases.

low octane

This problem may be related to the fact that you recently filled your car with low-octane gasoline. Be sure to use premium gasoline with an octane rating of 93 or higher in your BMW. If you have accidentally used low octane gasoline, consider adding an octane booster to your fuel tank to increase the octane rating of the gasoline in the tank.

Fuel injectors

One or more damaged fuel injectors can cause a moderate reduction in BMW driving power. If your mechanic determines that the fuel injectors are the problem, it is recommended (but not required) to replace them all at the same time.

Other possible causes of BMW transmission failure are cylinder head gasket, mass air flow sensor, turbo problems, fuel injectors. While it is impossible to know what caused the BMW transmission failure on your vehicle without reading the codes, in most cases this error is caused by a misfire.

Transmission failure in cold weather

If your transmission fails when you start your BMW in the morning, it's very likely that you:

• Have an old battery
• Presence of spark plugs that have not been replaced within the recommended interval
• Too many electronic devices plugged into auxiliary outlet

Transmission malfunction during acceleration

If you're trying to overtake another vehicle on the road and you're getting a transmission fault message while accelerating, you're most likely:

• You have a faulty high pressure fuel pump.
• Clogged fuel filter
• Damaged or dirty fuel injector.

Transmission failure after oil change

If you are experiencing BMW transmission failure after changing your engine oil, chances are high that:

• The sensor was accidentally disabled
• Spilled engine oil on the engine

BMW Drivetrain Error Messages

This is a list of possible error messages you may receive. The exact wording of the message may vary depending on the model.

• Transmission malfunction. drive slowly
• Transmission failure Maximum power not available
• Drive modern. The maximum transmit power is not available. Contact the service center.
• Transmission malfunction
• Full performance not available - Check service issue - Error message