307 ABS light; again

I had the same problem with the offside rear sensor on my 307 HDi SW. I had it replaced and after 2 months the problem returned.

I looked at the sensor signal with my oscilloscope and found it to be intermittent. The air gap between the sensor and the ring on the hub was too big. I loosened the sensor and put a wooden packing piece behind it to close the air gap a wee bit.

A horrible bodge, I know, but it's worked fine for six months so far.

That's very interesting, because after posting this morning, I did further googling, found the same suggestion (but using a metal shim, more professional :-) ). I reported back to my mechanic and he has just phoned to say that it has resolved the problem and he's on his way back here with the car.

This does raise serious concerns about the degree of electronics being fitted to cars. In our case, all the ABS computer can report is failing sensor whereas the sensor is OK, the fault being in the mechanical mounting.

There's no doubt that the onset of ECUs into cars has been a "good thing" (to quote from "1066 and all that") because no more do we have to fart about with plug and point gaps on wet cold mornings. if the battery is good, then the car will start.

The ABS I'm not so sure about because if you're a decent driver, the sort of braking problem that might need the ABS is only going to happen every couple of years, and then again, if you're trained to handle a skid; still no problem.

The rest of the electronics? Pah!

(Yes, I know that there are 20+ garages in my own home town, but once you've found a good guy 23 miles away, and have used his services for 19 years, you stick with him!)

The ABS light has now been tested on a 69-mile round trip (mechanic returns car, I have to take him back and then come home myself)

The sensor was shimmed to make up for the loss of metal by rust, and it is now solved after a week of head scratching (and probably very colourful language; I dread the bill arriving)

This begs the question as to why the experts at Peugeot do not know the answer to the problem, but just keep insisting that the sensor needs to be changed yet again, because that is what their computer system tells them.

There would seem to be a need to start a web-site to publicise wrinkles of this nature, and once again to give maintainability back to the man-in-the-street.

I'm glad you have got the problem sorted, and thanks for passing on what you've learned to the group.

I have to disagree with you on the value of ABS - regardless of how slow, sorry; 'careful', a driver someone may be, there can always be situations where the friction of the road surface is reduced unexpectedly (black ice/diesel spills) and a system which brakes each wheel according to the grip it has will always offer shorter stopping distances and better stability than a traditional braking system.

For those of us who enjoy driving in a more spirited manner, the triggering of ABS is more of a daily than a sub-annual occurance. It's nice to know that, in an emergency braking situation, the correct action (both for myself and for the majority of other road users) to take is the instinctive 'stamp on the brake as hard as possible', rather than having to rely on overiding ones instincts under difficult circumstances and call on driving skills which, for said careful drivers, are by definition very rarely practiced.

I mean no offence by any of this; I simply think that ABS is one of the few benefits of the increasing complexity of cars. EFI and ABS are pretty much the only gizmos which I think are worthwhile; I would live happily without trip computers, electric windows and mirrors, heated seatbelts and general mother-hen like warning bleeps and bongs, and I would take ABS in preference to airbags as a safety feature.

just my tuppence worth.