99 x20xev Poltergeist in rev counter - SpamCan61 {P}
afternoon all;

My lovely green Vectra X20XEV simtec 56.5 ECU has decided to devlop a new fault, as follows:-

I'm rattling up the M3 at around 60 all is normal, then the car suddenly judders and the rev counter starts fluctuating rapidly between 0 and 5000 rpm. I dip the clutch and the car stalls, flick ignition off and back on again and the car fires up and all is back to normal.

This has happened twice in a week, so I'm getting rather twitchy. I haven't checked the blink codes yet, but I suspect it will just give cam and crank sensor malfunction, like it always does when the engine isn't turning over - no blink codes with engine running.

My line of thinking is that it is likely that the reference source for the rpm display is likely to be the crank sensor, so if this sensor is going faulty ( hardly an unusual occurence on an X20XEV) this could give the fluctuating display.

Anyone got any other possibilities before I resort to blink codes / proper Tech 2 diagnosis?

Cheers.
99 x20xev Poltergeist in rev counter - Screwloose

I'm not familiar with blink codes, as I've got a few scanners, but can you be sure that the cam and crank codes are spurious? A Bosch system always has P0335 showing engine off - but a Simtec?

Is your cam belt loose? Cam sensors and their wiring are always worth a check too.

TB will be along later.....
99 x20xev Poltergeist in rev counter - SpamCan61 {P}
I'm not familiar with blink codes as I've got a few scanners but can you
be sure that the cam and crank codes are spurious? A Bosch system always has
P0335 showing engine off - but a Simtec?

It struck me as odd, but even when the car is running fine & dandy the cam and crank sensor errors still flag when I insert my paperclip. I must admit I'm assuming it's a Simtec ECU, but I don't think I've physically checked the label on the ECU itself on this Vectra, so I'd better do that. The older Simtec ECUs in my X20XEV Omegas always flagged the cam and crank as well.
Is your cam belt loose? Cam sensors and their wiring are always worth a check
too.


The cam belt , idlers, tensioner and OEM water pump were changed 20K miles ago, I guess I'd better have a look at the weekend though. I'd much rather it was cam than crank sensor as I assume the crank sensor change is just as much of a PITA on the Vectra as it was the Omega :-((

Looking through the service history the crank sensor was changed at 76K, but there is no record of a cam sensor change. I bought the car at 110K just over a year ago, it now has 141K on it.

I'm assuming crank as it would make more sense to me to drive the rev counter form the primary indictaor of rpm, the crankshaft, than the camshaft.


Thanks for the input Scrweloose.
99 x20xev Poltergeist in rev counter - topbloke
cam sensor fault/wireing to sensor new type available with modified connector (tighter fit)
99 x20xev Poltergeist in rev counter - SpamCan61 {P}
Yeah, cheers tb, I had to do the old to new type cam sensor conversion on the first X20XEV Omega I had, from memory there's an extra wire in the cable, which you need to earth. I really want this to be a cam sensor problem, just so much easier to fix than crank. I might swap with the cam sensor off my Omega which is still sitting on the drive, that was runing fine when I pensioned it off, other than the MOT fail on emissions I couldn't fix :-((.