RED light district = Yaw sensor?

[LVR]

Hi all

Can anyone provide some thoughts?

My wife has handed the 4.8is over to me to drive for a while as she's gotten fed up.

It has a red TPMS light on all of the time and no other lights or codes.

Air suspension works fine and is levelling straight away at start up EXCEPT if it's parked on a side slope ie one side of the car is lower than the other. Then the system stays asleep. If I raise the car with the switch it immediately goes up and after driving off settles back to the correct level.

I've got no codes other than the EBV brake force distribution listed.

I also have some drive train 'grinding' noise coming at 55km from the front end and which is particularly loud at all speeds after going around a right hand corner and accelerating ie under load. I'm thinking this is the guibo but not sure why it would throw a light.

I've done a search and read lots of older threads but can't find a definitive answer..

Any thoughts?