bigs

So...

I was having my wheels balanced today. And the very nice young technician guy invited me out to the shop to see an electrical-appearing wire with a small black "plug" on the end... hanging loose from the right rear brake caliper and rubbing on the inside of the rim as the wheel rotates.

This is apparently the ABS sensor wire, no?

There is a first little plug that appears to plug into the body of the inboard side of the brake caliper, then the wire runs upward through another little retaining clip, and a second small plug (the one that was dangling in my car) on the end of the wire plugs into the outboard portion of the brake caliper.

How does it work?

Randy Carter

Bigs, it's all controlled by the PFM board.

James-man

There should be two different sets of wires in that region. Brake pad wear sensor and ABS hookups. They all have plug-ins in similar locations. My first guess would be the brake pad wear sensor. I think it has just enough length to posibly reach the rim. The system should check both ABS and brake wear for errors. A danging wear sensor that remains intact will retain continuity and not trigger an error, and not flash an idiot light on the dash. ABS that comes detached should trigger an error, shouldn't it?

Like Bigs, I too am interested in how the ABS system works. I am aware of a magnet in the area of the ABS sensor. Is the ABS sensor a reed switch? What makes the ABS kick in - when one wheel stops when others are still rotating or is it deceleration based, detecting an impossibly fast cessation of rotation? I was going to google search it this week.

bigs

PFM board...

What's the steenkin' PFM board?

Randy Carter

PFM board. Acronym for Pure ****in' Magic. I dunno how it works beyond that.
Got Ya!

bigs

OUCH!!!

Steve Cattaneo

Good bath Room ABS reading.ABS

BC

I think this could get technical, so follow with me here Bigs.

You are gonna want to get prepared, get the car up, take off the wheel, maybe take a break before the real work begins, and start:

1) Plug the damn thing back in.

bigs

I did! I don't think it's gonna stay in.

1. From rubbing on the inside of the rim, the plug has been worn down a little. And,

2. There seems to be a small metal clip that holds it into its receptacle. The clip is missing.

But that's not my point anyway. I'm just curious as to what exactly this wire does and how the system works.

Mrmerlin

Bigs it sounds like the brake par wear sensor has fallen out of the pad we can get a new set of them for you just stop by the shop, we will fix your car, the ABS sensor is actually screwed into the hub of the suspension, it will also connect to the round junction block that the brake pad sensors connect to . If your ABS sensors is dangling then it will be making a lot of noise and psooibly damage the wheel, if its the brake pad sensor then it might just rub on the inside of the wheel and not make any noise........ ABS sensor is about the size of a spark plug the brake pad sensor is about the size of your pinky fingernail both are connected to wires , Stan

bigs

Steve -

Thanks. I'm a little bit smarter. But I also have a headache now!

bigs

Aha!

It must be the pad sensor. Little black plastic thingy, indeed about the size of my pinky fingernail. Shouldn't I have gotten some sort of dashboad warning message if it came loose and was just hanging?

I've already talked to Dave earlier today - I'm bringing the car up on Wed.

I assumed it was the ABS sensor, and I just got to wondering exactly what the sensor did and how it works.

Now... I'm wondering how the little brake pad sensor works? Heh, heh.

(You know, every classroom needs a dumb student lke me who isn't bashful about asking stupid questions... Maybe others will learn something from the responses too.)

BC

I was joshin.

Steve Cattaneo

That is the brake pad wear sensor, ABS is round.

Steve Cattaneo

[QUOTE=bigs]So...

Stop drinking cheap wine