00524 - Knock Sensor 1 (G61) 31-00 - Open or Short to Ground

[Gordon Sage]

This is regarding a 99 1.0 Lupo with the AER engine. After months of trying to fix the '00561 -  Mixture Adaptation' error, i.e. the vacuum leak, I finally got it running in an acceptable manner, albeit without a steady idle. To celebrate I went for an enjoyable run up into the Highlands, returning via a 70 mph cruise down the M9. Stopped for supermarket beer and set off home. However the car didn't feel right - hesitation on acceleration. Hooked up to VAGCOM and got the 00524 error. So I changed the knock sensor, checked its terminals for shorting. There's only 2 terminals, whereas Haynes Polo wiring diagram shows 3. Anyway one terminal clearly goes to earth and the other was fine with no evidence of a short.

But the problem remains and I'm reaching the end of the road with this car unless someone can point me to the source of this error and keep this Lupo on the road.

[Sausage]

http://wiki.ross-tech.com/wiki/index.php/16712/P0328/000808

Needs to be correctly torqued up, there's also ways to test them on or off the car with a meter.

[Gordon Sage]

Thanks for this. I did test the original (Bosch) sensor off the car and it appeared to be working ok but I decided to replace it as the easiest option. The original sensor must have been torqued up ok as the fault code had not appeared previously. The replacement might be just off as my torque wrench wouldn't read as low as required. I reckon now it must be a wiring problem triggered by my motorway thrash but where to look - that is the problem.