Replacing/repairing BCU (Body Control Unit) on 2005 RR HSE

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invisible999

Active Member
Posts
73
Location
US
Recently 2005 RR HSE (140K miles, US version) developed a situation: after locking car with remote or with the key, when unlocking it (either remote or key) rear doors, fuel cap and/or tailgate remain locked.

Based on my research across forums, people point out towards the problem with BCU (Body Control Unit) that is located under the passenger door. The strongest indication that it is BCU is that resetting BCU using central lock/unlock button on the console - pressing it 6-10 times to lock unlock the door - fixes this problem. It also fixes stiff steering that was before. Now, steering will get stiff again, but it is another problem I am going to deal later by replacing power steering pump and the fluid.

I want to focus on resolving situation with BCU. There are number of them available for sale on Ebay but what people are saying that one has to reprogram used BCUs and one must buy the unit that matches the hardware and software versions from the current car, so I have to pull the unit and check these versions.

My questions to the audience:
  • Except buying the same unit from other RR, can the existing one be repaired/fixed? - What kind of question should I ask to sellers on Ebay to make sure that I am getting functional/working unit?
  • What could be other reliable sources/shops to buy used unit (in the US)?
  • Finally, if I get unit from another RR, what need to be done (reprogramming, etc) to make sure it will work with my vehicle?

Thanks
 
Last edited:
I had random issues with mine, including the fob not working at all, unable to lock, unlock or start the car. Host of other issues to eg heater not working properly..
So far the fix appears to have been disconnecting the battery a couple of times and leaving it overnight.. worth a go and it's free and easy to try in case it fixes your problem.

I don't know anything about repairing it replacing the bcu though
 
Its a programable feature that can be changed, M changed ours to drivers door only on first press, 2 presses opens the rest.

J
Hi

Funny enough mine is the same as standard on my D3 of just the drivers door and then the rest

Must confess didn’t realise it was able to be changed until I looked on my gap iid

Also noted with regards to the doors being locked and then deadbolted, one press deadbolts all doors but believe the D4 are different in having to do 2 x clicks to be deadbolted

Plus really like the auto lock feature after setting off
 
Hi

Funny enough mine is the same as standard on my D3 of just the drivers door and then the rest

Must confess didn’t realise it was able to be changed until I looked on my gap iid

Also noted with regards to the doors being locked and then deadbolted, one press deadbolts all doors but believe the D4 are different in having to do 2 x clicks to be deadbolted

Plus really like the auto lock feature after setting off
I'm sure the one vs two presses is switahable in the config
 
BTW, I bought BCU off ebay, swapped with the existing one and my problems are gone. I also don't see the same error codes I saw with the previous BCU.
 
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