9two8

Can anyone confirm please if the below picture of an S4 Central warning computer is the same setup as that in my 80, 928s., and that pins 19 and 20 once jumpered will cancel the brake pad warning light

Trying to get rid once and for all !!! it,s driving me nuts after trying everything else.!

http://img826.imageshack.us/img826/7...1362centra.jpg

Ken
80 928 S
5 Speed

UK

Mark SF

Has trying everything included installing new wear sensors on all 4 wheels?

AO

I'm quite certain the brain is different and thus the pics are different as well. However, you should be able to look at the wiring diagrams for you year and trace back to what pins trigger the warning.

Personally, I have removed the pad wear sensors and connected the wires at each corner to defeat the system.

9two8

QUOTE-- Personally, I have removed the pad wear sensors and connected the wires at each corner to defeat the system...., I also did this ?

QUOTE-- Has trying everything included installing new wear sensors on all 4 wheels?..., not recently, but certainly in the past 2, 1/2 years.., and less than 1500 miles.
Thank,s

Ken
80 928 S
5 Speed

UK

Mark SF

I think you have a broken wire to one of the wheel sensors, before the connector at the strut. That's why shorting at the connector didn't fix the warning.

the flyin' scotsman

If you executed connecting the wires correctly then theres more issue.

Replacing the sensors then connecting the wires confirms the upstream issue.

I'd be looking for a broken wire/cable between the calipers and main harness connections.

supercedar

I jumped the 19 and 20 on my 1988 S4 for the same reason. Tried everything else except a complete wire harness.
Thomas

9two8

An update, today I removed the right rear wheel with the intention of splicing/soldering the warning wiring and removing the jumper that I put in some time back., but before this I thought I,d re-connect the wiring to the brake pad wiring.., fired up the engine and the brake pad warning light went out ( confused ? )

Having had this bother some time back, I jumpered both rear connectors with only the fronts still connected. So now I have 3 brakes connected to the warning sign, as opposed to 2.
Any thoughts why re-connecting the right rear would accomplish extinguishing the warning light ?

Ken
80 928 S
5 Speed

UK

GlenL

Because the circuit is now complete. It is essentially once long wire that runs from the brain through the four pads in series.

You never know what others have done to the car.

9two8

I guess that,s true, although I,ve owned it for twenty years now,

Ken
80 928 S
5 Speed

UK

GlenL

OK. Let me update that comment. You never know what you did to it in the past. At least that applies to me.

Mrmerlin

Ken its quite possible for the brake pad sensor wires to have a break in them.
if one was caught prying on the wire it can shear the wire while still leaving the insulation intact .

Note the sensor insulation is a different type than the rest of the wires it is a hi temp insulation and rather brittle compared to the rest of the system.
Note the wires used in the sensors are a silver based wire also quite brittle and its possible for it to either corrode ( due to damaged insulation) or to shear easier than the copper wires

As has been previously stated the brake sensors are a long string one break in any part of the string and the light is triggered.

You can test each sensor for continuity , usually a sensor has an internal open , removing the sensor from the string and connecting the car side of the harness at that particular wheel will connect the string together,
you may have more than one sensor damaged so do one wheel at a time to figure out the defect

9two8

.., many thank,s for your advice guy,s.., most appreciated !

Ken
80 928 S
5 Speed

UK

Tom in Austin

My "brake pads" warning goes off at random ... around once every couple of weeks, and always on my way back to work after lunch. No clue.

Would anyone who owns a 928 really not know the condition of their pads? Seems silly to create a warning system for something that has a long replacement interval in normal use.

GlenL

You're expecting a lot from dentist's wives.

These were sold as luxury cars with lots of features for the time. The view from most of the board is of performance cars maintained by the owners. A different model.