Car engine light on day one

Aj_newbie

Hello everyone

Hope you had a good start to 2025.

I purchased a used car from a bmw approved dealer. I drove the car back home yesterday. During the drive, on the motorway, there was a slightly stronger jerk on auto gear change around 50-60mph. Then my dashboard shows "Drivetrain malfunction. Full performance not available. Take the car to service centre" The car sopped changing gears, I could feel from the engine revs and noise. I stopped the car, stopped the engine, waited a couple of mins, restarted and it behaved as if nothing happened. I was able to drive at 65-70 smoothly.
Same issue after about 30 miles. Same resolution by restarting. But this time I noticed the engine light is 'on', on the dashboard.
This morning, the engine light is gone.

Given that the problem occurred on the first drive back home, do I stand a chance to return the car? (having no symptoms now is not going to help )

Suggestions please. Thanks in advance
Aj

ButterCheese

Yes take it back - the codes will still be stored when they come to scan it, and even if not then they should take it for a drive and wait until the code comes back on again.  But the dealer will have BMW-specialist code readers so shouldn't be a problem

force_ten1

Under the Consumer Rights Act 2015, you have a short term right to reject your car if it is of unsatisfactory quality, unfit for purpose or not as described. You can get a full refund. However, you should remember that this right is short-term and is only limited to 30 days from the date you bought your car.

https://www.themotorombudsman.org/knowledge-base/what-are-a-consumers-legal-rights-when-buying-a-car#:~:text=Under%20the%20Consumer%20Rights%20Act,date%20you%20bought%20your%20car.

that is a cut and paste from the motor ombudsman

the fact that it happened twice on the drive home i would be looking to reject the car rather than allow them the chance to repair it as a gear box fault that is restricting performance i would say makes the car unsatisfactory quality or unfit for purpose   

ButterCheese

Just be careful how and when you go about rejecting it though (if that's what you are going to do).  There have been many threads on here about taking the car back but then not receiving the money back.  It might not necessarily be a big job, could just be some sort of sensor issue and not a new gearbox, but it's up to you whether you giv them a chance to repair or whether you want to reject it.  It also depends very much on the dealer - they might be happy to give a refund, take the car back and sell it to someone else and hope the light doesn't come on again, or hope that the next owner lives too far away to bring it back

chrisw

If you're happy with the car otherwise, let them diagnose it first. As said, it might just be a sensor playing up which could happen on any car. Once you know what the issue is, then you can decide whether to have it repaired or reject the car completely.

Aj_newbie

Thanks everyone for your inputs.

I just took a drive to check whether the problem was one off. The message did pop up again, twice in 20 mile drive. Each time the message pops, the car stops changing the gears, I can see it from the engine noise and the revs. So it may be beyond some sensor malfunction, but I am no expert.

force_ten1

Aj_newbie said:

Thanks everyone for your inputs.

I just took a drive to check whether the problem was one off. The message did pop up again, twice in 20 mile drive. Each time the message pops, the car stops changing the gears, I can see it from the engine noise and the revs. So it may be beyond some sensor malfunction, but I am no expert.

you need to decide what you want to do moving forward i would say that you have grounds to reject on short term right to reject but don't be fooled into believing you have to give them a chance to repair. within 30 days they don't after 30days they do 

the fact that the fault clears when you power the car down and back on would suggest to me that it is a gearbox control module fault rather than a hard mechanical fault. but that is just a guess