ABS light on intermittently


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.

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

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

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.