ABS Issue

[twotonetruck]

Hello everyone, I've been having an issue recently with my ABS. Usually around 20 mph, the light comes on. Sometimes it won't come on at all. After decoding, I found six different error codes:

22 - missing right front speed signal
23 - erratic right front speed signal.
37 - erratic vehicle speed sensor signal.
66 - open or shorted pump motor relay.
73 - memory error.
86 - shorted anti-lock indicator lamp.

Where do I even start with diagnosing and has anyone had a similar issue? Truck is a 1995 C1500. Any feedback would be greatly appreciated!

 

[Schurkey]

Perhaps a moderator will move this thread out of ENGINES and into Axles + Brakes.

"I" would start by verifying the RF speed sensor and wire harness up to the ABS unit, using a scan tool if possible, and an ohmmeter/frequency counter if the scan tool won't read the sensor.

When I had a good, solid RF speed sensor signal on the scan tool, I'd clear the codes and drive it--see what codes if any come back.