toofer

I have been under the impression that the brakepad sensors are a closed circuit. When the wire in the sensor head gets worn thru the circuit is broken and the sensor light on the dash lights up and its time for new pads and sensor. I`m working on my 1980 928S Euro and this sensor problem has me close to pulling my hair out. The brakepads are almost new, PO replaced them 2000 miles ago. I`m to the point I connected both sensor wires on all 4 wheels together to make the light go out but that didn`t do it either. I need some help.

bd0nalds0n

The circuit has multiple connection points, and therefore multiple potential points of failure. Interruption at any point will cause the light to trip.

Here's a quote from Wally P from an earlier thread that discusses the brake pad warning system circuit. It would probably be helpful to have a schematic...:



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OK, here is the circuit...

Starts at the instrument panel connector On Brake Pad 1, terminal 9 of plug 4 on the instrument panel;
goes to T14, the connector on the inner left fender;
goes to the left front connector, then the sensor, then back to the connector, then back to T14;
Goes to K25 on the Central Electric, then out at M15;
Goes to T15 on the right inner fender;
Goes to the right connector, then the sensor, then back to the connector, then back to T15;
Goes to D15 at the Central Electric, then out at S14;
Goes to T17 in the spare tire compartment, then to the right rear connector, then the sensor, then the connector, then back to T17;
Goes to T16 in the spare tire compartment, then to the left rear connector, then to the sensor, then to the connector, then back to T16;
Goes to terminal 12 in T19, the large harness connector near the Central Electric Panel;
Goes to Brake Pad 2 on terminal 1 of plug 3 on the instrument panel.

That is almost two dozen connections on the circuit!

Have fun...