Hi can anybody tell me what these fault codes mean, 3c gear switch and 22 gearbox oil temp sensor, I have been told there are more than one sensor for the box.

Hi can anyone recommend a company to check my electrics and sensors? I'm having a few problems with a sensor on the gearbox I have been told it's one of two sensors, when the fault kicks in it give a message (failsafe mode)but also knocks out the light on the dash that tells you what driving mode your in. the garage I use checks everything and clears the fault but it comes back after a while. I have a 2003 RR v8 hse,