intermittent fault

clarkie46 · 11th May 2018, 20:06

I have an intermittent fault on electronics. My indicators do not flash on dash but work ok, sometimes i get a warning that a door is open, andmy central locking will open the doors but not close them. I have tried a different dash but this makes no difference. Is it possible it could be the BCU and if i bought another unit would it have to be programmed either used or new.
If i disconnect the battery overnight and reconnect everything works for a few minutes and then reverts back to the faults.

David Lawrence · 12th May 2018, 18:02

Quote:

Originally Posted by clarkie46

I have an intermittent fault on electronics. My indicators do not flash on dash but work ok, sometimes i get a warning that a door is open, andmy central locking will open the doors but not close them. I have tried a different dash but this makes no difference. Is it possible it could be the BCU and if i bought another unit would it have to be programmed either used or new.
If i disconnect the battery overnight and reconnect everything works for a few minutes and then reverts back to the faults.

You have a diesel, and one possibility is if you have a FBH fitted and it has had the K-bus wire cut on its connector (something people do to stop the heater acting up ) then that wire needs to be securely insulated and taped up. If it is bare wire and flapping up against something it can cause odd behaviour such as you describe.

It could also be a K-bus short on any other part of the car as well, but worth starting with the fbh.

klarzy · 12th May 2018, 18:30

Check the bonnet open button on the front of the car, these often need a clean and cause the locking issue...
Also disconnect the battery negative for a full 30 mins...

That should reset the busses

RoverDan · 12th May 2018, 20:57

You probably have a wet/corroded module somewhere that is corrupting the K bus signals. I had it in my tourer when the parking sensor ECU got wet and corroded due to a small but ongoing water leak.

I too feared the BCU was at fault but that's in one of the driest locations! A T4 session will help track down the offending article, but it may be a case of unplugging units in turn until the culprit is found. When I unplugged my faulty parking sensor ECU, everything went back to normal.

Long description here.

Maybe start by checking for water ingress in the boot - wheel well and side cubbies - and damp carpets throughout. Check any modules nearby any damp...

clarkie46 · 22nd May 2018, 15:21

Thanks very much to all who replied.
Left the car for a few days under the car port where it was warm and dry, reconnected the battery and all faults are gone. Looks like dampness somewhere so i will investigate further in all areas.

11th May 2018, 20:06	#1
clarkie46 Newbie rover 75 tourer Join Date: May 2013 Location: moodiesburn Posts: 11 Thanks: 0 Thanked 0 Times in 0 Posts	intermittent fault I have an intermittent fault on electronics. My indicators do not flash on dash but work ok, sometimes i get a warning that a door is open, andmy central locking will open the doors but not close them. I have tried a different dash but this makes no difference. Is it possible it could be the BCU and if i bought another unit would it have to be programmed either used or new. If i disconnect the battery overnight and reconnect everything works for a few minutes and then reverts back to the faults.

12th May 2018, 18:30	#3
klarzy This is my second home none but not gone Join Date: Mar 2013 Location: March, Cambs Posts: 16,437 Thanks: 894 Thanked 4,247 Times in 3,025 Posts	Check the bonnet open button on the front of the car, these often need a clean and cause the locking issue... Also disconnect the battery negative for a full 30 mins... That should reset the busses __________________ [SIGPIC][/SIGPIC]….All praise Bananaswan….

12th May 2018, 20:57	#4
RoverDan Avid contributor Rover 75 Saloon, Tourer, Limo Join Date: Feb 2011 Location: Exeter Posts: 233 Thanks: 52 Thanked 82 Times in 51 Posts	You probably have a wet/corroded module somewhere that is corrupting the K bus signals. I had it in my tourer when the parking sensor ECU got wet and corroded due to a small but ongoing water leak. I too feared the BCU was at fault but that's in one of the driest locations! A T4 session will help track down the offending article, but it may be a case of unplugging units in turn until the culprit is found. When I unplugged my faulty parking sensor ECU, everything went back to normal. Long description here. Maybe start by checking for water ingress in the boot - wheel well and side cubbies - and damp carpets throughout. Check any modules nearby any damp... __________________ -- CDT auto Club Saloon CDT auto Connoisseur SE Tourer CDT auto Connoisseur MacNeillie Limousine

22nd May 2018, 15:21	#5
clarkie46 Newbie rover 75 tourer Join Date: May 2013 Location: moodiesburn Posts: 11 Thanks: 0 Thanked 0 Times in 0 Posts	intermittent fault Thanks very much to all who replied. Left the car for a few days under the car port where it was warm and dry, reconnected the battery and all faults are gone. Looks like dampness somewhere so i will investigate further in all areas.