Brake lining warning

[Rufrob]

I have a 92-M5 and at my wits end.
I’ve searched high and low all over the Google-verse
I can’t get the brake lining warning turned off.
I got new sensors. Lots of meat on the pads. I traced the front and rear sensor wires into the main harness, no breaks. The brake fluid is topped up. All the fuses in the engine room and under the rear seat fuse box are good.
What am I missing?
Is there another fuse somewhere as some wiring diagram suggest?
Any advice would be greatly appreciated.


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[Old525i]

Have you looked for a short to ground?

[shogun]

The sensors are on the top of the pads on the driver LHD front AND passenger rear brakes. Did you change both?
Had your light come on before you changed the pads?
When there is no continuity through the sensors the brake warning comes on. You either have bad sensor/not correct installed or a break in the wiring.
Pull the plugs apart from brake pad sensor to engine bay close to the pads, make a wire bridge into the plug going to the engine bay, if the warning light disappears, then the fault is on the side towards the pads, if not, wire problem towards the engine bay. In case light goes out, check the sensor again, remove and insert the wear sensor on the new pad once more.

or do you have a Brake Light Circuit warning? http://www.nmia.com/~dgnrg/page_25.htm

[Rufrob]

Have you looked for a short to ground?

Yes. I traced the wires from the sensors to the main harness. I come not find any brakes. There is continuity on the pad side none on the harness side.

[Rufrob]

The e34 does not require a reset. The sensors are on the top of the pads on the driver LHD front AND passenger rear brakes. Did you change both?
Had your light come on before you changed the pads?
When there is no continuity through the sensors the brake warning comes on. You either have bad sensor/not correct installed or a break in the wiring.
Pull the plugs apart from brake pad sensor to engine bay close to the pads, make a wire bridge into the plug going to the engine bay, if the warning light disappears, then the fault is on the side towards the pads, if not, wire problem towards the engine bay. In case light goes out, check the sensor again, remove and insert the wear sensor on the new pad once more.

or do you have a Brake Light Circuit warning? http://www.nmia.com/~dgnrg/page_25.htm

I recently bought the car with good pads. I was dealing with many other issues and didn’t drive the car so I can’t remember if the light was on or not. I do remember the front sensor was disconnected
There is continuity on the pad side since the sensors are new but none on the harnesses side. The left front harnesse is very short with broken insulation so it was easy to trace to where it enters the main harness under the ABS pump.
The rear harness has 2 connectors one behind the backing plate the other on the chassis near the rear subframe which enters the main harness there and passes into the battery box. Here too there is continuity on the pad side and none on the main harness side.
No it’s not the brake light warning.
Braking lining warning.
Yesterday I found a blown fuse under the left rear seat but that didn’t solve the issue. I’ve tried leaving the ignition on position 1 and 2. Still no reset and the stop test has no codes.

[shogun]

stomp test does not work on your Japan spec. car, only works on US cars.
Try a test with the wire bridge as I posted above.
Did you drive some km after you repaired the sensor harness? I am not sure what is correct: someone wrote:
Normally the warning light should go off with ignition in position 2 and wait some minutes.
In another post I read this: warning reset on E34: ignition key in position 1 and wait 30 seconds w/o starting the engine.
Another post: The CCM will eliminate some errors after you start driving, it is checking in case of serious warnings, after the engine has been started 5 times and fault is solved, warning goes out.
If not, check the wires again, they are very thin and can easily be damaged.
Another possibility is that the CCM check control module is showing error codes, here a repair of the CCM in German language, but with lots of pics to show you where to re-solder http://www.e34-welt.de/tips_tricks/R...0e34%20e32.pdf
in case you have automatic electric headlight aim motors, these also can cause problems for the CCM to give error codes. In Europe they install resistors for that problem and clean the motors.

Which fuse under rear seat was blown? Be careful, there were some fires under the rear seat, especially with the rear window heater
https://www.bimmerforums.com/forum/s...ms-in-pictures
https://www.bimmerforums.com/forum/s...rear-seat-pics

wiring diagrams by built year, but these are US spec , so some things can be different from your Japan spec. car https://shark.armchair.mb.ca/~dave/BMW/e34/

Add your model, built year/month to your profile, easier for us to help

[Rufrob]

My car is US spec. I bought it from California
I’ll try driving the car with a bypass wire. But would it matter if I have continuity at the connector on the pad side and not on the harness side?
I saw but can’t find again a wiring diagram which showed a fuse in the system. Both front and rear wiring going from the sensors to the instrument cluster and a fuse.


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[Rufrob]

thanks for the wiring diagram. I check it when I get home.


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[Rufrob]

The wiring diagram didn’t help. It appears to be 1 continuous circuit sensors to instrument cluster.


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[Rufrob]

Jumped wires 10&25 on X16 connector. Now the brake lining warning is out and
all the check function work. Hurray


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[shogun]

that is of course also possible directly at the rear plug X16 yellow of the instrument cluster
pin 10 E= input 0,5 ge/bl = yellow/blue, Brake line sensor rear right
pin 25 A = output 0,5 ge/ = yellow, Brake line sensor left front