Disco 2 bcu repair/replacement info please ?

Hi folks just bought a 2000 discovery 2 td5 auto project been after another discofor a while and found this one with a solid chassis only ever had minor welding. Needs a few things doing and been off the road for 10 months.

Main problem I was told is bcu got damp and is knackered hence key fobs don't work, flashing m and s lights on dash ect and also doesn't change gears properly.

Is the gear changing affected by bcu?

Also he gave me a spare matched ecu and bcu but said it was from a manual td5 disco and wouldn't work due to that fact it coming from a manual. Can they not be altered/reprogrammed to work on auto?


Thanks for any help or info in advance.

Hi, you can forget about the manual engine ECU which is not compatible but the BCU will work cos it's completely programmable. All you need is a dedicated diagnostic tool to set it for your vehicle, pair it with the ECU and synk the fobs. If you find somebody with nanocom it's a max 10 minutes job

The flashing m&s light indicate that the vehicle is in limp mode, 3rd gear forward and reverse due to a fault in the auto transmission, mechanical or electrical, there are 20 plus faults that all cause this.
The bcu supplies power to the xyz switch which tells the auto transmission which position the gear selector lever is in failure of which causes the flashing m&s lights so yes bcu can affect gear changes.

Excellent thanks both very helpful replys.

I will have to find someone local to me(Aberdeenshire Scotland ) with nanocom and get it sorted.

Thanks again

A problem would arise if the bcu were in a locked state as it is near impossible to unlock it.
I have edited this post to remove incorrect information.

ROY SIMPSON said:

A problem would arise if the bcu were in a locked state as it is near impossible to unlock it unless paired with its corresponding ECU which is why you were given a matched pair.

Click to expand...

Sorry but i must contradict you. If the BCU was removed in locked/immobilised state it's irrelevant if it's paired with an ECU or not cos the diagnostics won't work with that particular BCU and the ECU doesnt help at all. In that case without EKA or a sync'd fob it's useless anyway. The fact that it's paired with an ECU would help just to fit them both to a vehicle and be able to start it(provided the BCU is not locked) as the paired ECU knows the security code that's all

For information about bcu look a callrova web site .