Transmission fault / car won't go into gear question.

[ronreece]

We have a 2008 750i with 80K miles.

For the last few months, the car has been shifting strange (especially when starting up or downshifting). It's been somewhat sporadic though.

Yesterday, my wife was driving the car and as she started up from a stop light, she felt a slight stutter while shifting, then the car gave a warning.

As best as she could recall, the yellow cog/gear on the display console came on with an exclamation point, the main display read "transmission fault", that the car would only go into "D" mode (or drive mode?), and the check engine light came on. It also said "the fault may be resolved by restarting".

She drove into a nearby parking lot, parked the car, and shut off the engine. She waited a while and restated the car. At that point, the same faults came back on the displays.

The car will not shift into any gear, and stays in the park mode. The "P" stays illuminated and yellow indicator arrows (to the left of "D", "P", "R") constantly flash.

I had the car towed home and scanned the car for error codes. In the transmission, there was an error code that read "4E23 electronic pressure control valve". From what I understand, this code is for the pressure control 4 solenoid valve - one of the EDS pressure regulating solenoids in the mechatronic unit mounted in the transmission.

Anyone have any similar experiences with this issue, or advice on solving the problem? It seems pretty straight forward to install a new ZF solenoid kit, pan, and fluid. But before dropping over $500 on the parts, I would like to make sure this will solve the problem.

One other thing that is strange, after doing a bit of reading, it would seem that the car should be able to go into "limp mode", but the car won't go into (any) gear?

Any advice would be greatly appreciated!

[bmwdirtracer]

There is a manual release for the shifter, which may allow you to select drive. You tube should have a picture of how to do it. On your car, as I recall, you pry up the shifter panel, turn a small screwdriver slot 1/4 turn at the top left, remove a small plastic cover, then stick a thin screwdriver into a hole, and pull towards you. Your owner's manual may even have the procedure, but you tube will for sure.

The last 3 cars I've had with that code, all said exactly the same thing, when tested with ISTA (BMW's diag computer). That message was "replace Mechatronics". Of course, that's a $3000 unit, plus a bunch of labor, and you can't use a used one in a 2008, because they are part of the anti-theft system.

For one of these 3, we installed a solenoid kit, and it worked. The second, the owner bought a new Mechatronics unit. The third one the owner called his insurance company, reported that this had occurred when he drove into a flooded street, and the car was totaled.

Be aware that your engine is going to have expensive troubles soon anyway; you may want to consider cutting your losses. This car requires ~$4000 a year in maintenance and repairs, even when the expensive stuff isn't dying.

Sorry, it's one of the BMWs which I'd never consider buying, because it's so prone to expensive failures.

[ronreece]

I think you may be thinking of a 740i shifter, that's mounted down in front of/ between front seats. Our 750i has the "paddle" style shifter that's on the steering column.
Any idea how to manually shift this car or get it into limp mode?

[bmwdirtracer]

https://www.youtube.com/watch?v=6hqLxeNEwyU