Break Pad light problem - 986 Forum - The Community for Porsche Boxster & Cayman Owners

smeech · 08-20-2008, 07:21 AM

Hi folks
First post so be kind.

I have a '98 Boxster and it currently has the break pad warning light coming on and off at will. I took it to a mechanic friend of mine and he said there is actually nothing wrong with the pads so therefore it must be something electrical.

Has anyone else had this problem and if so are there any easy fixes?

Thanks

Lil bastard · 08-20-2008, 09:51 AM

The Brake Pad sensor is essentially a wire that once worn through throws the warning light.

It's possible that the wire broke inside it's insulation, or that the electrical connector is either not tight or corroded and not allowing the circuit to complete. Check these out.

Also, a week ago I helped a friend swap the rotors and pads on his 328i BMW (which only has two wear sensors - 1 on each axle). After completing the job, which included new wear sensors (same concept as the Porsche ones), his warning light did not go off.

We hooked up my generic Actron PocketScan Code Reader CP9125 and the car read 'no codes'. But, when we started the car again, the brake wear warning light was off so I guess the code reader reset it. So you might try that as well.

Jeph · 08-20-2008, 04:35 PM

If you can figure out which sensor is causing the light, you may just replace the sensor. They're only 12 USD or 6.5 pounds.

My brake wear light comes on some times when I clean my wheels. It goes off after I drive a bit.

smeech · 08-21-2008, 01:16 AM

Thanks for replies guys.

That's the thing. It's totally random. In rain, in sun, when I use the brakes, when I don't.

Trouble is i'm more than happy to take the wheels off and have a look but I just don't know what I should be looking for!

Lil bastard · 08-21-2008, 05:44 PM

If you remove the wheel and look at the caliper, you'll see a wire clipped into the retaining clip. Follow this wire back toward the car and see where it connects. Pull and reseat the connector, check for corrosion. If that doesn't work, take a DMM (multimeter) and pull the connector for a sensor and check it for continuity. If you don't have continuity, then you'll need to replace that sensor wire. Because of the randomness you speak of, I think 1 wire may be broken inside it's insulation, probably where it gets pinched by the retainer, sometimes it makes contact and you have no light, other times it breaks the circuit and the light comes on.

smeech · 08-22-2008, 01:02 AM

Thanks guys. Will investigate and report back my findings.

Thanks again.