Hi All,
The rotary gear selector in my 2011 tdv8 decided to stay in reverse this weekend.

I was actually in low box reversing my trailer when it happened.
Went to put it into drive and nothing, locked in reverse.
IID indicated a gear selector solenoid lock failure.
Eventually I had to switch the car off.
Then I couldn't start it because it was in gear.
Had to leave the car stranded overnight.
I got the module out and stripped it down.
Solenoid works fine powered off a 9v supply so must be on the board or other fault.
Rebuilt unit back into park, and managed to start the car but no gear selection.

At least I got the car home via a tow and the transmission release lever.

Every day is a school day owning a RR!

I see a number of evoke and velar owners have had the same issue.

Anyone had similar with this box set up! Is it just a case of replacing the unit or does it have to go into the dealers?

I'd rather do it myself as not got a lot of positive things to say about my local main dealers unfortunately.

Cheers, TF

Are you accustomed to holding the foot-brake applied with the gearbox in any position where the brake pedal must be pressed to change in 1 direction or the other, eg reverse to park, for more than just the short time to rotate the selector, thus keeping the lock motor powered for more than a couple of seconds?

The selector module uses a 1 ohm resistor to monitor the lock motor and if the motor is powered for more than a short period then the resistor will get very hot and melt the solder causing the resistor to no longer be attached at both ends or 1 or both joints becoming high resistance, thus cutting power to the lock motor. A fault code will occur for a short circuit on the lock motor but the fault is actually open circuit. The resistor can be re-soldered with a fine point soldering iron that is set to get hot enough to melt the lead-free solder.

Edit: Reversing with the brake pedal even lightly pressed will cause the lock motor to be powered so if done for more than a short time will cause the problem. The circuit board would do well to have a remotely mounted much higher wattage resistor.
Sometimes a burn mark can be seen around this resistor.

thanks for that info,

I have had the board out, but no obvious signs of burning around any component.

However I will check the resistors out again. Any idea of where the offending resistor sits on the board?

Cheers. TF

Here's a pdf prepared by a member on AULRO (I'll add his name if I can track it down). The last picture has the 1 ohm resistor marked. Sometimes the resistor isn't burnt but re-soldering its ends fixes the problem presumably due to a high resistance joint having developed when the solder melted.

https://www.fullfatrr.com/gallery/albums/u...oblems.pdf