ABS light on intermittently

XJ40
1

Hi

The ABS light on my 1990 XJ40 Sovereign is coming on intermittently, it can stay on for full journeys for days, then it suddenly goes off, however I am finding it is on more than it is off.

I do not have any issues with brake performance.

2

Plenty of posts in the archive regarding re-flowing the solder joints in the ABS module in the boot/trunk

3

Also, make sure the pickup sensors at the wheels are clean and with good connections.

4

David …

My priority of troubleshooting this would be …

  1. ABS overvoltage relay … Check that the relay opens and closes. Also check that when the relay is closed that it actually does have continuity through the load side.

  2. ABS wheel sensors … Check for continuity and condition.

  3. ABS electronic control unit … Replace. Lots of used units online for under $50.