Vauxhall Astra - limp mode - fuel issue?

el Fenomeno

Hi, wondering if anyone can shed some light on this as we're stumped.

My brother and mother both get their fuel at the same garage, and both drive diesel cars.

My mum drives a Mercedes, and one day a few weeks back it went into limp mode. We initially thought she had accidentally put Petrol in to it so we had it drained and had the fuel filter replaced and topped it back up with Diesel. The car is now running fine, though we've been able to confirm that she topped it up with Diesel so that wasn't the problem.

The garage where she gets her fuel had allowed Diesel tanks to run empty a few times in the few weeks prior which should not be allowed happen, so we're guessing that perhaps the Diesel was contaminated. Just a guess.

My brother gets his diesel at the same garage, and a couple of days after my mother's car went into limp mode, his did also. He drives a 2012 Vauxhall Astra CDTI, 1.7L Manual.

As I said, car went into limp mode so we had a diagnostic ran on it. I don't have the print out on me, I'll be able to post up the exact error messages later today or tomorrow, but it was in relation to the pressure sensor at the back of the fuel pump, and some other sensor. Not a mechanic so can't say for sure what the problem was, but we were told it was in relation to the fuel line/system anyway.

So we had the diesel drained and replaced, fuel filter replaced, pressure sensor replaced, and this other sensor replaced (can't remember what sensor it was). The diagnostic and the mechanic also confirmed that it was NOT an injector problem.

Now all error messages are cleared, and nothing shows up on a diagnostic. The car starts fine, sounds fine - no funny noises or anything - and drives fine for a couple of minutes until it enters limp mode again. The only message that appears is to service the vehicle soon. Even when you run a diagnostic AFTER it goes into limp mode again, there is nothing showing as an issue - the car looks perfect.

Has anyone any suggestions on what else should be looked? The mechanic is stumped. Still investigating, but just thought I'd reach out here to see if anyone has encountered similar or has any hunches as to what it could be.

Thanks

Lucifer

If the service vehicle soon light comes on it will store a trouble code. You need it checked with a different computer. Have often seen other computers show no faults but Opel computer will show.

el Fenomeno

Thanks for the advice. I'll see if we can get it read by a dedicated Opel/Vauxhall computer.