Brake Pad Sensor Warning and General Error Illuminated

[txhokie4life]

 

Replaced all 4 sensors, ohmed out the new sensors.

Checked the fluid level.  Shorted the brake fluid sensor connector wires.

 

no change in behavior.

 

Tried a UDT999 and a Durametric -- no codes that I could dig up.

 

running out of ideas.

Edited January 3, 2023 by txhokie4life

[JFP in PA]

Porsche brake pad wear sensors function on continuity; each wheel has a wire loop running to the sensor and back to the DME.  If there is a break in that loop anywhere, not just at the pad itself, you will get the sensor warning.  As this sensor system runs all over the car, and the insulation is a vegetable-based coating, it is a favorite "edible" for rodents, which leads to wires getting cut.

[txhokie4life]

JFP, 

 

Unlikely its rodents -- been garage kept, and no other signs, but good to know.

 

Is there a way to determine which of the 4 circuits is complaining?  Is there a resistance or voltage measurement at the connectors?

 

Mike

 

[JFP in PA]

You would need to check each of the four circuits for continuity at the DME, there is no voltage on the circuits, and I am not aware of any resistance ratings.   Another way to find it would be to create a "jumper" that you could hook up at the DME end of each circuit, as soon as the bad circuit was replaced by the jumper, the signal should stop.  It is really a process of elimination.......

[txhokie4life]

looking at the electrical diagrams -- it looks like it is one daisy chain into the pair of brake pad pins on the Central Informer module.

 

One end of the chain goes through the central electric, the other side does not.  Should be able to devise a method to check this out.

 

Mike

 

[JFP in PA]

It is a very basic system.

[txhokie4life]

Resolved -- not exactly sure of the actual solution.

 

I'm suspecting a non-fully inserted brake pad sensor -- but I did assemble and disassemble the Central Informer connectors and probed there and all of the sensors,

after a few tries -- things started working.

 

M