Hi all... I have a dilemma. I have a 2014 530 D M Sport Auto with a gearbox that has gone into Park and wont come out.. Garage says its probably going to need a gearbox rebuild at around the £3k mark.. A second hand gearbox costs less than a third of that but is the risk worth it?

Morning Chris

Welcome to the Forum

Oh dear I hope the garage is not a BMW Dealer or Specialist and are just an ill informed Independent. How did the car drive before the issue? If it was OK then you had the "stuck in park" problem

First this is not an uncommon issue and is fairly well covered on the Internet

Task 1. Check all the transmission linked fuses there are several from memory also check the relay.

Task 2. If all fuses and relays are in good order get that Gearbox Control Module checked. A job better done by someone with BMW or ZF capable diagnostics.

A full Diagnostic scan should tell you more, it would be embarrassing to spend a lot of money rebuilding/changing the transmission to discover it was a 20p fuse

Good Luck

Dave

Hi Dave and thank you for the welcome and advice.. It always drove fine before hand.. I came home from work, parked it up, saw I had parked like a fool and restarted it to straighten it up.. It went into D but then slipped back into P by itself and stayed the same way.. The RAC came out, ran their diagnostic on the transmission and it came back with 420641, Parking lock incorrectly applied: plausibility driver command /sensor confirmation. Intermittent. Some research suggested that the common fault is the gear selector unit. I found a replacement, provided it to the garage in Taunton and their response it it isn't that. They said it might be a low battery ( just over 11 volts) and if the car wasn't told the battery was replaced, it can cause problems.. I looked at the fuses under the glove box but the ones I want to look at are buried underneath a relay that I cant get out. I asked if low or dirty transmission fluid might cause it, the garage suggested not, especially if the engine is cold.. I'm still concerned that it might be that as a previous service identified a small oil leak but they weren't sure where from.. I just don't know what to do for the best...

Hi Chris

You need to go online and search the Register of BMW Specialists there should be one close by

The garage your using seem a little lost, the most common problem is Fuses as already said there are several dependent on model, to muddy the water a little more sometimes they are not blown just dirty so need checking carefully (I use a good contact cleaner and a new fuse) They are correct that low battery voltage can cause issues and 11v would indicate a discharged or dying battery, have you tried charging it ? If it won't take a charge then it needs replacing and registering to the chassis (not difficult and can be done after issues are fixed) At the front fuse box check fuses 63 Automatic Transmission Control 10 amp and 64 Gear Selector Switch 7.5 amp How do they know it wasn't the Gear Selector unit ? Did they check fuses?

With a fully charged Battery I would carry out a Diagnostic scan note any codes then clear the fault memory and register the Battery correctly. Then check voltages at the charging points under the bonnet, Engine and Ignition off should be 12.5v minimum Engine running Voltage checked at the same place should be 14.6v. Now hopefully you will have a driving Beemer

Hope this Helps

Dave