My buddy and I are trying to figure out why his SSPS (Speed Sensitive Power Steering) light is staying on. At first it was intermittent but now it stays on all the time. The steering is a little touchy at high speeds which is an indication the SSPS is not performing properly.

How does the SSPS work? Does it have its own sensor?
Can anyone chime in and give any info? Can't find much online.
Just need somewhere to start troubleshooting.

Thanks in advance!