TDV8 2009 43000 miles,
I took car to an indie to resolve my problem where the car would not turn over, the key-fobs did not work and the stop lights were on until a hard reset.
The indie resolved the problem, but when I came to leave I found that the low speed enhanced PAS was not working.
The indi investigated and found that there was no voltage at the servotronic valve according to his diagnostic tool.
I also noted that the key fob now needed 2 clicks to open all doors where previously only one had been required.
I understand that this is a programable option so clearly something has changed.

He double checked the equipment on another RR and this showed voltage at the servotronic valve.

My question is can the servotronic valve be inadvertently switched off using diagnostic equipment and if so how can it be reinstated?

Before going to the garage there were no PAS issues so I am convinced that this is a software rather than hardware issue.

I would like to return to the indie with suggestions to resolve the problem so you help would be appreciated.

I have had some help with wiring diagrams form Graeme which is appreciated.

I also noted that the indie had put a fuse in position 54 which according to my hanbook and lid diagram should be spare.

Removal of this fuse has no discernable effect that I have noticed,

I am very pleased that the indie fixed the starting issue but would very much like to get this issue fixed too.

Your suggestions would be greatly appreciated.

AFAIK, It's not possible to turn off the Servotronic anywhere in the system - inadvertently or not.

If there's no voltage at the valve, it's possibly a connector fault at the BCM or Servotronic, a wiring fault or the BCM has become faulty.
The variable assistance from the Servotronic is created by varying the voltage to the valve by the BCM (Strictly speaking it's not a varying voltage, but a Pulse Width Modulation (PWM) signal).
If measured via a digital voltmeter, you should see upto approx. 7.5V at zero speed, reducing to 2.5V or so at 50 mph plus.

I've not heard of wiring or connector problems (yet) via the forums, but Servotronic valves & BCMs are known to become faulty.
The faulty BCMs usually give other symptoms such as locking issues & I think window operation faults.

To test / eliminate the Servotronic valve you can feed it 12V via a separate feed while disconnected from the BCM / standard wiring loom (being very careful not to damage the valve connector pins !). You should get full assistance permanently to confirm the valve is working OK (I ran for a couple of months like that while waiting to fix other problems on our 3.6 TDV8)
Do you know the Indie did to resolve your original problem ?
What was done / changed ? Paul,
2001 Discovery 2 TD5, 211,000 miles & climbing
2006 FFRR TDV8 Vogue 145,000 miles & climbing
Member of Midland (Land) Rover Owners Club, www.mroc.co.uk

Thank you for replying to my post, your information is going to be very useful.
I was obviously hoping that it would be a problem which could be fixed with key strokes as the problem was not there before the indi fixed the other issues.
I've read elsewhere that connecting a 12v feed directly to the servotronic valve is best done with a spare connector rather than cutting into the existing wire.

Thanks again, as my wife commented it is amazing how helpful people are on this forum.