My 2000 xj8 vdp is showing “traction control unavailable” and “asc unavailable” on the instrument cluster. What can be causing this? I already cleaned the wheel speed sensors and it didn’t help. Any suggestions would be greatly appreciated. Thanks in advance!

 

The 2 most likely culprits for this kind of failure are:

1. Check all inline connectors to all 4 speed sensors for contact and corrosion. Clean them and apply CRC 2.26.

2. But sadly the most likely fault are cold welds (=cracked solder points) inside of the ABS module. The complete ABS-PCB was in a solder-bath during production for a fixed duration, and this time was long enough for all the smaller solder points, but not for the 2 big ones, where the power comes in - and this shows now - years later, There 2 big solder points need to be re-soldered. It's a bit of the struggle to get the ABS module off and on again, but I did that on my X308.

Here is a video about it - I have not seen the video in its entirety, but the important part starts at time 3:45:

I can't remember if I drilled a hole into the cover like shown in the video, or of I managed to pry the lid open...

 

pcolapacker sent me this pic of one of his ABS modules

 

Changing the battery for a 100amp fixed it for me

 

Low voltage across the connection joint can cause the issue which is most
likely caused by the solder point weakness. Isolating the problem and completing
a refresh of the weld is the most effective manner of eliminating the warnings. There
is a lot of vibration at this connection which exacerbates the issue.