172 ABS - self error checking, or can it store faults and fail to self check?

[alistairolsen]

I know the 172 does a self-check on the ABS system when you start it. Does it have any capacity to store long term faults and disable this?

I.e. if you have fixed the fault will the light definitely go out? Or can it become stuck and need reset with CLIP?

Thanks

 

[Louis]

Itll go out.

 

[JamesBryan]

If it's a sensor fault that's been fixed it'll go out on it's own.

It may still show up in a scan as a historic fault but the light won't be on.

 

[alistairolsen]

Okay, so I can chase the fault with faith then when I've fixed it, it will go away. That's a good start.

After being stood for some time, when I started the car the ABS and serv lights were on. During the front end refresh I cleaned and inspected the front rings and fitted two new sensors. I've since cleaned the rear rings.

The lights come on with the ignition and fail to go out, which suggests to me it's a sensor or wiring fault rather than rings because it's not occuring with wheel speed.

I've checked the brake switch and the brake lights operate as expected.

So I guess resistance checks of all the sensors next....

 

[JamesBryan]

Okay, so I can chase the fault with faith then when I've fixed it, it will go away. That's a good start.

After being stood for some time, when I started the car the ABS and serv lights were on. During the front end refresh I cleaned and inspected the front rings and fitted two new sensors. I've since cleaned the rear rings.

The lights come on with the ignition and fail to go out, which suggests to me it's a sensor or wiring fault rather than rings because it's not occuring with wheel speed.

I've checked the brake switch and the brake lights operate as expected.

So I guess resistance checks of all the sensors next....

Have you tried driving it first?

That might clear it, but not if a sensor is dead.

 

[alistairolsen]

I've driven it a few hundred yards on a private road, but can't do more without an MOT.

Odds are one of the new, non gen front sensors is faulty out of the packet...

 

[JamesBryan]

I've driven it a few hundred yards on a private road, but can't do more without an MOT.

Odds are one of the new, non gen front sensors is faulty out of the packet...

Either that or a rear one.

 

[alistairolsen]

Possible, but they were working when parked and look fine and haven't been disturbed. Fronts were cracked and I suspect water ingress whilst sitting so I replaced them. Will check out the plugs and check resistance on all four and see.