Skip the auto shop - Our mechanics make house calls

Q: Transmission intermittently won't shift to next gear

asked by on

My car has a SMG transmission. The problem began around 1 month ago and it is intermittent. Sometimes the transmission won’t shift at all, no matter which gear the car is in. Sometimes the gear that it is in won’t change. I have to take my foot off the gas pedal so that it will shift. When on the highway, if I go from first-second-third- then it won’t shift into fourth and I have to take my foot off the gas to get it to shift into fifth. One time, while changing gear with the paddle shift, it stopped at 2nd and a SMG light came on telling me to check the dealership. So I took the car to the BMW dealer and they ran a diagnostic on the transmission. They said that the transmission stopped at third gear and it didn’t shift any more. Then, they told me that I needed a new transmission. That doesn’t make sense to me since I can still shift the gear. The SMG doesn’t shift some times, even when on 5th and driving on the highway, it won’t shift into 6th until I take my foot off the gas. I’ve heard different analysis of the problem - computer - reset battery, etc. Do you think my car needs a new SMG transmission, and if not, what do you suggest?

It is very possible that the transmission may require a full rebuild or a replacement in order for it to perform properly. Although you are able to shift into other gears, if certain gears are not working correctly, transmission damage may be the cause.

If the transmission has already been diagnosed by the dealer that it needs replacement and the transmission is still not shifting properly, it is unlikely that the transmission will get any better without replacement.

It does not hurt to attempt any reset procedure that may be available, but it is also unlikely that a reset of any kind will resolve transmission issues. Small things to check before replacing the transmission if possible would be the fluid level and any trouble codes that may have been stored due to the issue your transmission is causing.

If any codes exist, this may lead you to other possible parts inside the transmission that may be able to be replaced and have your transmission working again as it should. You can get a second opinion from an local expert, such as one from YourMechanic, in order to diagnose your shifting problem and advise you on the next steps.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: 2003 Honda Civic not moving in reverse

Unfortunately there could be several reasons as to why your Honda Civic is unable to engage reverse gear when you shift the transmission into reverse. Knowing if your Civic is equipped with a manual or automatic transmission can greatly assist...

Q: Car has P0420 code and idles around 1500-2000

There are a number of things that code P0420 relates to, most of which will directly or indirectly affect the performance of the catalytic converter. This may be caused by a faulty oxygen sensor, fuel injector leaks, faulty spark plugs,...

Q: Problems shifting gears

It sounds like your 2002 Honda Passport may have an issue with its gear selection sensor. This sensor provides information to the powertrain control module as to which gear the vehicle is in. If this sensor is giving false...

Related articles

How Do Power Car Windows Increase Passenger Safety?
Power windows are responsible for approximately 2,000 emergency room visits every year. When a power window closes, it exerts enough force to bruise or break bones, crush fingers, or restrict an airway. Though...
How Long Does a Heater Control Valve Last?
Keeping the right amount of coolant in a car is essential in keeping the engine at the right temperature. Failing to have the right amount of coolant or even bad elements...
P2428 OBD-II Trouble Code: Exhaust Gas Temperature Too High Bank 1
P2428 code definition A P2428 trouble code signifies that the PCM has detected a problem in the exhaust gas temperature sensor circuit in bank 1, which subsequently contains the number one...