I have had this RRS 2007 TDV8 for a few months after buying second hand. It started with battery drain issues. If you left it too long (couple of days) witout starting it would not start and the battery would need to be recharged. I had a local garage diagnose alternator problems as the voltage output was spiking. This was changed and I changed the battery myself just incase the cells were damaged from the faulty alternator. All was well for about 100 miles and then came the headache. I was driving it one day around 30 miles from home and i get a fault beep along with the doors locking and unlocking, the hazards flashing (although you cant see in the car) and the interior lught on. If I stop the car it wont start again and just comes up with vehicle lean when cornering. The fault seems to clear itself after a while and the car starts and it t will give you half a mile and come back on again.
It has been to a RR specialist today to go on SDD diagnostics and has came up with ALOT of codes mainly Lost communication codes.
Here are a few:
ARCM Module -
U0126-87 - Lost communication with steering angle sensor module - Missing message lost communication with vehicle dynamics control module
BCM Module -
B1D06-15 - left turn indicator - circuit short to battery or open
B1B70-01 - Interconnection network bus
B1C99 -15 - Right corner lamp circuit - circuit short to battery or open
B1c98-15 - left corner lamp circuit - circuit short to battery or open
IPC Module
U018-87 - Lost communiction with front lighting control module
U0132-87 - Lost communication with suspension control module
PBM Module
C1a00-16 - Control Module
U0122-87 - Lost communication with vehicle dynamics control module
U0101-87 - Lost communication with Transmission control module

Also more errors within steering angle sensor module and transmission control module relating to system voltage low or lost communication

Maybe worth noting that the battery cover is missing and i did notice cables in water behind battery and also this model has a sunroof fitted.

Any help would be very much appreciated as the land rover specialist doesnt know whats wrong and wants to have it in for awhile and check everything over.

There’s a few issues that are similar to this so I’ll list issues I know of

Water in the passenger foot well from perished/blocked sunroof drains. To check this you need to lift the passenger carpet and have a real good feel around. Lots of people have rejected this thinking that the top of the carpet was dry so there was no leak. Wrong.

A faulty gearbox module. Someone else maybe able to help diagnose that one.

Cheap brake light bulbs.

Brake light switch faulty

The cluster has a bad solder joint on the circuit board, commonly diagnosed by smacking the top of the dash and things working again. This is common but less likely as the dash goes off to (which you haven’t mentioned) and doesn’t stop the car starting.

A cheap Alternator, lots of people reporting that fitting a Densi Alternator fixed their cars after fitting cheaper after market parts.

If you have water in the battery area it won’t do any good so dry it out and try and find where it’s coming from. Check the windscreen for bad fitting and behind the black A pillar trim as there a few unused holes that should be taped over but at 10+ years old, the glue is drying out and they can peel off.

There’s a few things to consider. Hopefully some people who have experienced this can chime in and give you alternative ideas or develop on those I’ve mentioned. 2019 5.0 SC SVA (Current)
2012 5.0 SC AB. Sadly written off by a campervan
23 plate Focus ST (Current)
1942 VEP Ford GPW Jeep (Willys) (Current)
1943 Whites M16 Halftrack (Current)
16 plate Eurofighter Typhoon, 2 x Eurojet engines with 20,000lbs thrust each. 1380mph

I believe the Engine and Transfer Box are situated behind the battery, if you have cables floating around in water by the battery I would try drying all that out as can't imagine it will do the ECU's any good as water may have entered them. Only a suggestion

Cheers
Col

Thank you for your replies and suggestions. I will look to see what alternator was fitted but i dont think it was the densi alternator. Ive tried a few brake switches and still the same.
Today i have took up the carpet in the passenger footwell and you guessed it, there is water!
would never of thought to look as the top of the carpet is bone dry. I have opened the sunroof and poured water down the drains and all do seem to flow outside of the car underneath however some water definately is also coming into the car as i see it flow to under the passenger carpet where the cables are.
Could this be the issue here just wet cables?
Any one know how to fix this also?
Thanks
Simon

That’ll do it, it’s probably tracked into the fuse box and other have reported the sill being very wet too. You need to fix the problem and get lots of air circulating to dry it out. 2019 5.0 SC SVA (Current)
2012 5.0 SC AB. Sadly written off by a campervan
23 plate Focus ST (Current)
1942 VEP Ford GPW Jeep (Willys) (Current)
1943 Whites M16 Halftrack (Current)
16 plate Eurofighter Typhoon, 2 x Eurojet engines with 20,000lbs thrust each. 1380mph

Just an update - I havnt got round to fixing the sunroof drain however I sent the instrument cluster off to get repaired. It cost £200 but now the car works perfect. I have a iid tool now too and cleared the codes and nothing is coming back after driving a couple of hundred miles!