polo 9n - brake wear indicator fault (not usual issue)

[DavidBlack]

I've got a 2004 polo 1.4 which shows a brake wear indicator on the dash combined with a beep at startup.

I've checked all 4 brakes, inner and outer pads, and all are like new.

The wear indicator is only on the rear (passenger/right side). The sensor, wire and connection is tightly fitted with no visible damage.

I've measured the sensor and it shows 1.7 ohm and continuity.
I've measured at the connection (car side not sensor side) and it shows +12V (pink) on one pin and nothing on the other (yellow).

I tried shorting the two pins with no effect (wear indicator still shown). Trying shorting the wires further up (under dashboard) thinking maybe the connection is duff, with no effect.
Checked all the fuses (although there shouldn't be any fuse for the brake wear indicator) and all are fine.

So now i'm thinking that I have to check the other end, however it seems very unlikely that the connection is loose there.

So two questions:
1. Where is the other end connected ? To the ECU ? and where is the location of it (engine compartment or under dash)?
2. Any other ideas to what to check ?

[Crasher]

If it has the system on the right rear it should also be present on the left front. The system works on a closed earth circuit principle from pin 32 of the main dash plug out to the left front sensor and back in trough to the right rear and then back to the dash at pin 1 of the 8 pin plug.



A new left front cable is 6Q0 927 903 S and costs £46.07 from VW.

[DavidBlack]

crasher, thanks for your reply.

I also wondered why there was only a brake wear sensor at the rear and none at the front. Now if the front has been "fixed" by the previous owner and has now become disconnected, that might explain it.

However, that would mean that the signal goes to rear first ( i could measure it) and then continues to front and then back to dash. So I need to check the front left side again.