A few days ago my XC70's yellow engine warning light started coming on whenever we pull on the handbrake.

If the engine is switched off (car is parked in driveway) just as I pull on the handbrake, the engine warning light comes on, nothing else.

If the engine is on, the engine warning light comes on whenever I lift the handbrake, as does the handbrake light (as you would expect).

I'm suspicious that there is no engine fault, more like a sensor or indicator fault.

Any thoughts?

Thanks,
Paul