These are usually software glitch faults.
There is a level sensor going into the sump at the rear as far as I remember.

 

When I interrogated the fault with PP it could not communicate with the ECU but was ok when I went into parameters, my guess was the software was made for various models perhaps some have Oil temp sensors?

Thanks for your input.

 

Its a common "false positive". Most pre facelift 307s (or at least the couple of dozen I've diagnosticed) don't have an oil temperature gauge.

 

Thanks for all your input into this issue, I think we can safely assume it's down to software.

 

I always wondered if it did indeed have the sender unit and wiring, it just didn't connect to anywhere on the dash.

The 306 was like that - you'd find the wiring loom was already there for things like rear electric windows when it had manual and so on.

 

i have the same oil temp inop signal on my 53 plate rhs, it dont have a oil temp sensor on mine so i wouldn't worry about it.