Hi All,

So.. I had this problem a week or so back and after checking the alternator was working fine - it was and is less than 4 years old (genuine part), I changed the Battery for a YBX5019 Yuasa Silver High Performance Car Battery 12V 100Ah HSB019 one, as the one in the SC was around 6 years old, knowing that a failing battery can cause the issue below...

..which was .. driving along, doing a steady 30mph when all of a sudden I lost drive and all the engine would rev freely despite being in drive... I moved it in between gears but now joy and left it in Park with the handbrake on.

Whipped out the IID Tool and these codes popped up -

IPC-Instrument Pack
U0402-68 (2E) Invalid data received from transmission control module - Algorithm based failure - event information
( on 21-05-2025 22:03:54 at 96672 mi )

PCM-Engine Petrol
U0402-81 (36) Invalid data received from transmission control module - Bus signal/message failure - invalid serial data received

U0402-86 (36) Invalid data received from transmission control module - Bus signal/message failure - signal is invalid

VDM-Vehicle Dynamic

U0402-68 (0B) Invalid data received from transmission control module - Algorithm based failure - event information
( on 21-05-2025 22:03:51 at 96672 mi )

I cleared the codes and then proceeded on my way without issue for another 15miles until I got home.

Anyone have any wise words as to what this could be? I'm thinking along the lines of a circuit in the mechatronic unit in the Gearbox ? Gavin

2005 Range Rover Vogue SE 4.2 Supercharged V8

Follow my 4.2 Supercharged antics -
https://www.fullfatrr.com/forum/topic63354.html
https://www.instagram.com/l322_supercharged/
https://www.youtube.com/channel/UC8ChHNSdscnJarKjBLd_IAg
https://www.youtube.com/@ChallengingClassics

Any ideas anyone ? Gavin

2005 Range Rover Vogue SE 4.2 Supercharged V8

Follow my 4.2 Supercharged antics -
https://www.fullfatrr.com/forum/topic63354.html
https://www.instagram.com/l322_supercharged/
https://www.youtube.com/channel/UC8ChHNSdscnJarKjBLd_IAg
https://www.youtube.com/@ChallengingClassics

Had the same after a gearbox oil and filter change. Can’t remember the codes, but it felt like the clutch cable had gone on a conventional clutch car.

Cleared the faults and drive home and all was fine. I did have a dicky suspension issue at the same time, which was a dodgy wire, but 2 months in and I’d forgotten all about it.

Hi Gavin,

My old 4.2 did similar to this and I changed the gearbox when it was the transfer box that had failed.

Have a read of these 2 threads:

https://www.fullfatrr.com/forum/topic59943.html

https://www.fullfatrr.com/forum/topic59970.html

Also page 11 on this thread:

https://www.fullfatrr.com/forum/topic57991-150.html

Do your comms faults clear or do they come back the second you start the car?

If you can clear them, are you able to switch between high and low range?

I'd also drain the oil out of the transfer box if you can as mine was shiny when this happened to mine.

David. 2002 4.6 Vogue SE - Alveston Red with Lightstone Leather
2012 Range Rover 5.0 SC Autobiography in Indus Silver with Jet/Ivory Interior
2012 Range Rover 4.4 TDV8 Autobiography in Baltic Blue with Sand Interior
2013 Range Rover Sport SDV6 HSE Black Edition in Santorini Black with Ebony Interior