Discovery TD5 bcu issues?

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Kyletrek

New Member
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Location
Doncaster
Afternoon all,

I’m new to the forum so please bear with me, I have used the search feature but I’m only getting 2-3 threads with no answers but I’m sure they will be on here somewhere.

I have just bought a discovery 2 TD5 auto I’ve got a number of electrical issues with it at the moment which were not apparent when I bought it. Here’s the list so far
No rear wiper/wash
No heated rear window
Central locking not working from remote or key (alarm works)
M&S lights for gearbox but selects drive (third only) and reverse
No indicators
No interior lights

From a bit of googling I’ve found this is most likely to be a BCU fault or possibly wiring to BCU, could anyone confirm this and help with a solution or link to a thread for help it would be much appreciated
 
Hi and welcome :)

I can't help at all, electrical issues with the D2 was the main reason for not bothering to get one, even when I had the money ;)

But if we as @sierrafery if he can help as he is the wizard on these things.

All the best.
 
There is a possibility that all of your faults are BCU related, but before you go all guns blazing down that route are you sure that you don't have at least some individual faults?
For instance, I believe that all of the circuits in the rear tailgate door utilise a single earth wire, so it might be worth checking that. The wiring to any door does have a weak spot where it's under some mechanical stress, namely in the hinge area.
The first thing to check when the central locking fails to work off the keyfob is the condition of the radio receiver unit which is located in the roofspace, just in front of the rear sun roof.
The M&S lights are often caused by a problem with the XYZ switch on the gearbox.
Your indicator problems could be the stalk, which would be the first check. Do the Hazard flashers work?
The interior lights could be a BCU problem, but I would check all the festoon bulbs first, then check the appropriate fuses.
Do you have the Emergency Key Access (EKA) code for your vehicle?
I would also advise you to download a copy of RAVE, the workshop manual and electrical circuit diagrams from:-
http://www.green-oval.com/data/lr/rave01.iso

And also take a look at @neilly's advice on the vehicle and alarm problems at:-
https://www.landyzone.co.uk/land-rover/handy-buying-alarm-info.311291/#post-4173216
 
Your list of faults do seem to indicate that your bcu is the culprit and unfortunately the bcu is unrepairable except by an expert ( Search CALLROVA).
If you have access to a nanocom, hawkeye to read the fault codes stored (generic codes readers do not work with TD5 as it is not obd compliant) I do not think there is a fault code or diagnostic function to indicate that the bcu itself is the source of the faults.
It is only when you get multiple faults associated with the systems controlled by bcu that you realise that it is causing the problems.
One reason i think it is the bcu is that the gear selector system. Is powered through the bcu with its own dedicated supply unused by anything else and failure of the switch in the bcu will result in the failure you are experiencing with the gear box.
However your problem could be in the wiring if the systems share a comon connector.
If don't already you need to have a copy of rave ( landrovers own workshop manual) and associated electrical library and wiring diagrams for your vehicle which you can probably down load from here or d2boys club to help you understand the problems.
If you decide to replace the bcu it is not plug and play but needs to be synced to the vehicle with dedicated tester like nanocom, hawkeye etc., also be aware that if you buy a used one you cannot reduce the mileage stored on it.
 
brian47 said:
There is a possibility that all of your faults are BCU related, but before you go all guns blazing down that route are you sure that you don't have at least some individual faults?
For instance, I believe that all of the circuits in the rear tailgate door utilise a single earth wire, so it might be worth checking that. The wiring to any door does have a weak spot where it's under some mechanical stress, namely in the hinge area.
The first thing to check when the central locking fails to work off the keyfob is the condition of the radio receiver unit which is located in the roofspace, just in front of the rear sun roof.
The M&S lights are often caused by a problem with the XYZ switch on the gearbox.
Your indicator problems could be the stalk, which would be the first check. Do the Hazard flashers work?
The interior lights could be a BCU problem, but I would check all the festoon bulbs first, then check the appropriate fuses.
Do you have the Emergency Key Access (EKA) code for your vehicle?
I would also advise you to download a copy of RAVE, the workshop manual and electrical circuit diagrams from:-
http://www.green-oval.com/data/lr/rave01.iso

And also take a look at @neilly's advice on the vehicle and alarm problems at:-
https://www.landyzone.co.uk/land-rover/handy-buying-alarm-info.311291/#post-4173216
Click to expand...


Thanks for the great advice I will look into what you have suggested and investigate, I was looking to find some wiring diagrams so much appreciated for the link, also the hazard lights do not work either but the indicators show on the dashboard
 
Last edited:
ROY SIMPSON said:
Your list of faults do seem to indicate that your bcu is the culprit and unfortunately the bcu is unrepairable except by an expert ( Search CALLROVA).
If you have access to a nanocom, hawkeye to read the fault codes stored (generic codes readers do not work with TD5 as it is not obd compliant) I do not think there is a fault code or diagnostic function to indicate that the bcu itself is the source of the faults.
It is only when you get multiple faults associated with the systems controlled by bcu that you realise that it is causing the problems.
One reason i think it is the bcu is that the gear selector system. Is powered through the bcu with its own dedicated supply unused by anything else and failure of the switch in the bcu will result in the failure you are experiencing with the gear box.
However your problem could be in the wiring if the systems share a comon connector.
If don't already you need to have a copy of rave ( landrovers own workshop manual) and associated electrical library and wiring diagrams for your vehicle which you can probably down load from here or d2boys club to help you understand the problems.
If you decide to replace the bcu it is not plug and play but needs to be synced to the vehicle with dedicated tester like nanocom, hawkeye etc., also be aware that if you buy a used one you cannot reduce the mileage stored on it.
Click to expand...


As above thanks for the great advice, I have been looking at the nanocom tool and will look to purchase one soon, mileage is not an issue as I’ve got 208000 miles on the clock.
 
Well jumped in the disco today and the gearbox has gone back to normal, I started to check all the fuses and there all fine but I had no time for checking wiring.

Still no indicators or hazards but still need to chase the wiring.

I’ve sussed out the interior lights there was no bulbs in them and the middle one is missing

I’ll carry on with my fault finding and get the old bus sorted out
 
Kyletrek said:
Afternoon all,

I’m new to the forum so please bear with me, I have used the search feature but I’m only getting 2-3 threads with no answers but I’m sure they will be on here somewhere.

I have just bought a discovery 2 TD5 auto I’ve got a number of electrical issues with it at the moment which were not apparent when I bought it. Here’s the list so far
No rear wiper/wash
No heated rear window
Central locking not working from remote or key (alarm works)
M&S lights for gearbox but selects drive (third only) and reverse
No indicators
No interior lights

From a bit of googling I’ve found this is most likely to be a BCU fault or possibly wiring to BCU, could anyone confirm this and help with a solution or link to a thread for help it would be much appreciated
Click to expand...
. hi i have a simular issue if anyone can help, if you press the horn it brings on 3 amigos but no horn, sometimes makes abs pump vibrate, central locking not working, and button on dash does same as horn, turn lights on and that also brings on 3 amigos, was told it was a bcu problem so changed that had it reprogrammed with a nancom and still have same isues, if any one can help please
 
It's good that you ruled out the BCU cos it was very suspect for such symtoms. Replace the interior fusebox to be ruled out as well
 
If the BCU is not programmed well it will not work at all, the engine immobilised or some warning lamps will not work but would not give such symptoms, if you are 100% certain that the interior fusebox is OK(eyeballing it is irrelevant) rule out the engine bay fusebox too
 
He got it to fire up but that's all. Just dont think he knows how to use nanocom and dont think he matched it up properly. It's a night mare.
 
Well no 1 actually bothered to try and help out in any way but I sorted it myself. Wont bother to come to this site again. For advice.useless
 
Yep, almost as useless as the guy who reprogrammed the bcu - from what you say. Not sure just how that becomes our fault...but hey...you won't see this anyway. Bye!!!
 
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