I am back in Range Rover ownership with a 2005 RRS 4.2sc.
It has quite a few faults that I am working through but would value your opinions/help with a few things?
The main issue is the car has the Transmission Error come up when you engage Drive.
I have scanned it with my icarsoft and I have the following errors.

p0056..oxygen sensor heater circuit bank 2 sensor 2 ( unrelated to transmission error I believe)
P0579..speed control multifunction imput A ?
B1c57…ignition relay circuit
Bib02..low frequency coil

I believe the transmission has two faults, one electrical and one gearbox related.
The error code that comes up when drive engaged stoping manual and sport mode.
However if you switch the lights on and then engage drive you have no errors and sport and manual mode work.
Assuming that when the lights are engaged the selector sources power from an alternative source?

The second issue I believe is mechanical and transmission related is I get a whiplash thud as it changes from 1st to 2nd gear, I have tried manual gear changes from 1 to 2 to 3 and it works so believe the transmission may need a fluid change or the megatronic needs servicing?
I have removed the passenger seat to access the wiring loom running the length of the passenger sil , this does not look to bad with no real bad water ingress however I managed to fix the central locking straight away rejoining two of the wires.

Sorry for the long post , hope someone with a similar experience can point me in the right direction

Regards Mark

Forgot to add these additional errors come up on scan when you switch on lights and engage gear.
U0155..lost comms with cluster.
P081c..Park imput circuit
U0182…lost comms with front lighting module
U0159…lost comms with parking assist module
So no transmission error comes up when the lights are on and drives engaged plus the sport and manual mode work.

from the codes you may have more than issue... however, below are what i've seen....
tcm water ingress
mech'solenoids, sleeve etc
torque converter
coolant contamination

or a filter & fluid change might solve it, which works 90% of the time

Thanks…

Assume you mean the megatronic solenoids ?
And a gearbox fluid change.
My next job was to remove the battery and access the TCM and ECM/ECU that are situated there ?

It would be worth going around the car ensuring the various earthing points are tight/connected/not corroded. Bad earths can cause a number of error issues.

Also, check the alternator and battery health (assuming not already done).

The ECU and TCM are behind the battery box and it's not unknown for issues to occur if someone has been hamfisted when throwing water around washing the engine bay (why they wash an engine bay is beyond me but some people do it). 2012 SDV6 - it's missing a couple of cylinders
2008 TDV8 - it was a labour of love and is much missed

Thanks 👍

The previous owner replaced the battery and I measure it at 13.94v at idle.
Plan to whip out the TCM and check for corrosion at the unit and the plug/wiring.

Read on one of the forums about the earth points in the front nearside wheel arch and they serve the TCM as well as others I think.
It’s not my everyday car so can take my time and work through the faults.

No point measuring the voltage at idle, measure the battery after its been standing at least overnight.
You are looking for 12.6 volts or better. 2026 P460e Autobiography on order

2022 HSE Dynamic P400e

2017 Discovery 3.0 HSE Silicon Silver Nimbus interior and a few extra toys SOLD

2013 HSE Black, Orkney Grey, Ebony Seats and Ivory Interior SOLD

2006 HSE

Plus a few other cars inbetween!

In the wiring loom are splices. This is where 3 or more wires join (crimped) together and get blue tape wrapped around them.

They are usually long the sills.

I suspect your fault is caused by a red wire splice (that needs redoing). I can't tell you where it is, but here is an example post.

https://www.disco3.co.uk/forum/splice-f-tr...red+splice

P.S The way the green wire slice stops the remote key working. Search for that may show you pictures of the splice

jimbg wrote:

No point measuring the voltage at idle, measure the battery after its been standing at least overnight.
You are looking for 12.6 volts or better.

Andy K wrote:

In the wiring loom are splices. This is where 3 or more wires join (crimped) together and get blue tape wrapped around them.

They are usually long the sills.

I suspect your fault is caused by a red wire splice (that needs redoing). I can't tell you where it is, but here is an example post.

https://www.disco3.co.uk/forum/splice-f-tr...red+splice

P.S The way the green wire slice stops the remote key working. Search for that may show you pictures of the splice

Respliced and soldered the red wires found in the passenger sill loom unfortunately still have the same error.
Will check all the other crimped joints however it looks like it has not suffered with any major water ingress.
Will move on to the TCM and ECU behind the battery next to see if I have any corrosion there

Hi All,

Still have the transmission error coming up when drive engaged….

So far I have eliminated any broken wires or corrosion in the passenger sill wiring loom.


The previous owner replaced the stick selector.

Removed the TCM which had only minor corrosion on the pins and plug, which I have now cleaned.
Inside the TCM there was no sign of water ingress.

While I was removing the TCM I checked the two connectors at the ECM/ECU showed no corrosion but cleaned them anyway.

Put it back together and checked again, however same transmission error code when drive engaged.
Shows error code P081C
The lights on first then engage Drive shows no error of dashboard and I can engage sport mode and manual gears 123.
This then shows error U0155 when this method tried.

Can anyone help out with either previous experience or knowledge of the LR3/Sport ??

Search for the fault code on here or disco3

Here is one example

https://www.rrsport.co.uk/forum/topic55539.html?highlight=p081c

Thanks Andy

Will do

Reading up on a few forums …i believe it’s a voltage supply issue to the gear shifter if the headlight trick works, so will be looking at the fuses on the BCM fusebox.

The other thing I am unsure of is the lamps/leds on the gear selector are they supposed illuminated on the sport like the L322 ?
I know the dashboard shows you what gear you have selected but I have no illumination on the shifter PRND ?
Can anyone confirm this please