ABS light coming on when stationary

[rossjacko]

So I've had ABS judder at low speed in the 182 pretty much since I've had it. Thought it'd be the usual suspect of dodgy rings - nope all OK. Rears look new too.

Had a fault code of brake switch, so I put a new one in yesterday. However it still exists.

Today after work I started the car and thought I'd try holding my foot on the brake before I even go anywhere - low and behold it comes on.

Is this likely to be the whole ABS module? Or is there a pressure switch somewhere?

Thoughts welcomed. Cheers!

 

[oVerboost.]

Is the judder still there since changing the rings?

If it's only the light that comes on with the brakes, could it be an earthing issue? UCH? Do you have access to a ramp where you can take all the wheels off and then test wiring to each sensor to see if it isolates the fault to one corner?

 

[rossjacko]

Front rings are a bit rusty but I've cleaned them up best I can without getting a grinder in there to do them more. Rears look new, changed before my ownership.

Potential earth problem I guess. Yes have ramp access, I could check continuity across each wheel sensor. Don't they just put out a voltage though?

What's UCH?

I think it's a fault with the pedal end, as I said I hadn't even moved anywhere, pressed the pedal and after a couple of seconds of holding it down the light came on.

 

[rossjacko]

Front rings are a bit rusty but I've cleaned them up best I can without getting a grinder in there to do them more. Rears look new, changed before my ownership.

Potential earth problem I guess. Yes have ramp access, I could check continuity across each wheel sensor. Don't they just put out a voltage though?

What's UCH?

I think it's a fault with the pedal end, as I said I hadn't even moved anywhere, pressed the pedal and after a couple of seconds of holding it down the light came on.

 

[rossjacko]

So I adjusted the brake light switch yesterday and it's sorted this now.

ABS rings will need replacing in the near future though, or a better clean up than what I gave them last time.