Tip the rear seats forward and you will see a round flap in the carpet about 170mm diameter. Lift that up and underneath there is a cover over the connectors to the fuel pump/fuel sender unit.

When it said it was empty, did the light come on or was it just the case that the needle was at the bottom of the gauge? If so and it does it again, try pressing the night panel button on/off to see if that cures the problem.

 

Thanks for the reply. The warning light came on too.

Today both gauge and warning light were behaving themselves so maybe I wont have to do anything, but just to keep me on my toes the oil pressure warning light flashed on!

It's going to get a sump off clean out tomorrow, so assuming I get there without mishap I can get it checked properly then.
I'm concerned it seems to have consumed a lot of oil since it was serviced two weeks ago. No sign of a leak, no smell of burning oil, just very low on the dipstick when I checked.

My first saabs (96 v4, 99, 99EMS) were totally trouble free, just hope this one is too after the teething problems!

Thanks again
Mike

 

You didn't follow up on this but I have had a similar experience. Just today got around to looking in the fuel tank and am pretty sure that the problem was the baffle. It could be moved about and got in the way when I tried to remove the fuel pump/gauge. I removed it and filled up with petrol. The gauge went straight to full which it usually doesn't when it gets stuck on zero. I will shortly put the full story on my website Nicks Saab site

 

My 9-5 Aero (M04) would only read 3/4 full when the tank was brimmed. Was like it when I bought it. Specialist replaced the fuel sender.