Rebuilding Xantia ABS main loom cabling to sensor

[andmcit]

Strange one - at the ECU I've got a reading of a duff sensor on the offside
rear. In trying to see the rear multplug connector to take a reading off
it with a meter at that point I've discovered the main sheathing and plastic
plug which has a designed 90degree bend in it seems to be broken and
bursting apart - possibly from being brittle when I actually disturbed it.
This looks the likely culprit for the lack of signal to the ECU rather than
the usual failed sensor.

If anyone has been here before me, is there simply 2 wires feeding into the
sensor or is there an additional shielding in the main cabling on the car's
loom that wont take kindly to a spliced section of new wiring?

Andrew

[CitroJim]

I don't think it'll be a problem Andrew. The wiring from the ABS sensor itself to the plug is coaxial (like TV areial cable) and from then onward I'm not sure but I'd guess it too is coax, much like the wire on the TDC sensor.

Making a joint in coax will not adversely affect anything. Carefully join, solder and insulate the inner with heat shrink and then pull the outer over the inner joint, solder and insulate with heat shrink and all should be fine.

[jeremy]

My BX sensor cables (which I believe to be typical - are a simple screened cable with a single centre FLEXIBLE conductor.

At one stage I was driving round with 3 sensors repaired by soldering in sections of new co-ax cable as the outer covers on mine seemed porous and had allowed the screening to corrode away.

The frequencies involved are about audio - I had to sisten to mine to trace an intermittent fault.

[AndersDK]

The only reason the cable being a "coaxial" type is its flexibility. A standard 2 wire cable is less flexible but can still be used not degrading functionality - because of the low frequencies and rather high (~1V) signal levels involved.

The receiver electronisc in the ABS ECU is still a balanced type using the "ground" wire from the sensor as a noise decoupling wire.