Look around the starter motor and oil cooler,you should see 2 pressure switches and the oil flow control solenoid

 

Thanks Valer - would you say this would be an easy job for an enthusiastic diy’er ? Or is there other components that would need removing to get at these sensors

 

There's very little that's easy to get at on these modern cars,it needs to be got at from underneath so a ramp would make life a lot easier

 

 

Thanks again Valer I’ll have a look after work tomorrow

 

Grab a photo if you can, it will help anyone else finding this thread.

 

Valer - oil pressure sensor on a 1.6cdti J Astra exactly where you said it would be Jacked car up lying on your back feet sticking out the front if the car !! at the back of the engine the oil pressure sensor is located just above the oil cooler - photo below - however the oil pressure switch is another 8” up towards the top of the engine and no idea how you or a garage would get to this to change it .