Hi,

Are you sure that all ABS security lamp are OK ?
(orange lamp AND red lamp)
Test your red lamp with your hand brake.
When you switch your engine on, they should light on during five secondes.

Other point, if you have pressure probleme with ABS Mark2, you have 2 lamps switched on : orange AND red lamp, toghether.

If you have orange lamp on, it is just an electronic problem.
Often, it is dirty sensor, dirty wheel sensor, or to much play on bearing (front or rear)

Regards

Claude