Hi, I'm getting a bit desperate as I cannot find out what the hell is going on. I start the car and drive away and if I brake there is a horrible crunching sound, when I get to about 30mph the ABS warning light comes on and there is a non function message on the dash, then the brakes are fine and work normally with no crunching. I've had it looked at by the garage and they say there is nothing wrong with anything mechanical, all pads, discs and bearings are fine, and they cannot find anything else, even with the computer. The only thing I've noticed is at about the speed this happens the digits giving the speed flicker. probably nothing to do with it but I don't know. Anyone got any clues? Thanks, J.
Posted 06 July 2018 - 10:43 AM
You mention ABS in your title- could the problem lie in the ABS sensor ring area? The speedo flicker would also seem to point that way.
C4 Grand Picasso 1.6 HDi 16V FAP/DPFS 110, -Auto (DV6 - 80kW) (C4) (DT) (2008)
Posted 06 July 2018 - 11:44 AM
The initial crunching sounds like ABS kicking in - does the brake pedal vibrate too ?
Afterwards the ABS is probably disabled - hence the warning lights.
It sounds like a sensor, or ring.
The speedo is fed from the gearbox, so shouldn't be affected, but the electronics might be picking up the ABS glitch, as the ABS doesn't know what speed the car is doing, because of the fault (if that makes sense.. )
Posted 08 July 2018 - 09:26 AM
Posted 08 July 2018 - 09:36 AM
Posted 08 July 2018 - 09:17 PM
The ABS rings are on the driveshafts they are slightly magnetized, so the ABS sensor picks this up,
If the ring is broken, or rusty,then it loses sync and can't work.
Depends on what car you have as to which kind it is.....petrol, diesel, esp, etc.....
Get it plugged into a diagnostic machine, and they can tell you more as to which wheel, and what sensor/ring
Posted 09 July 2018 - 02:25 PM
OK, thanks for the info, I will investigate and report back, J.