hwyrnr

1984 928s auto

when I hit a bump in the road my brake pad sensor light come on. It seems to do it if the rear suspension gets a jolt. I checked the pads and they have plenty of material on them. I checked if the connectors were secured and they appear to be seated well. I pulled the rear wheels off and the wires are secured to the chassis and not hanging and rubbing on the axles. I can’t seem to find any bare wires.

Anyone have any suggestions on what to check next, or where else to look for chafed wires.

Thanks, James

StratfordShark

Follow the rear sensor wiring a bit further to the connectors mounted to front of spare tyre well.

Also check the front sensors too for proper fit in connector barrels.

dr bob

The sensing current in those loops is small enough that a tiny bit of corrosion with affect the reading. Try a little bit of DeOxit in the connectors to clean that. The "happens when I hit a bump" symptom points more to a broken wire where it flexes though. Go into the connectors in the spare wheel area mentioned above, using your DMM set to measure Ohms. Then reach around each wheel and move the sensor cable where it normally flexes to see if it changes the continuity through the loop as you wiggle the wire.

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When I bought my car, it had about 20k on the odometer, and the pads looked very good. I watched them wear over the first miles, but was surprised at how much pad was still left when the first warning came up at about 50k. The sensor function is pretty conservative, it turns out.

kombatrok

I disabled mine. Some people don't like the idea of removing a factory feature, but I would rather not have unnecessary systems like that, particularly if they have a propensity for trouble.

Just check the pads every now and then.

hwyrnr

Thanks guys, When I get time Ill check the connector in the spare tire area. Ill try to see if I can find if a wire is internally broke with the DMM. I didn't check the front, so I probably should check.

James