ABS Module was installed about a year ago and I never had any problems but speedo didn't work then either. When doing some brake lines I removed it. Yes the cluster test was good. Any procedures to check this module? Only thing left is to check wiring from axle to cab buttt it's all wrapped up inside wire wrap or w/e..
Did you get any numbers popping up on the Odometer? If the cluster doesn't receive a vehicle speed message from the PCM it will throw code 920. If it doesnt throw that code, then the spedometer is displaying the vehicle speed as the PCM believes it to be. The PCM gets its vehicle speed directly from the CCD bus from the ABS module.
Since I do not have the $3K tool required to read CCD Bus messages, I have no clue what exactly is communicated between all of the controllers.
Should the IC not be showing any codes, then two things may be bad. Either the ABS module, or the IC itself. I doubt the PCM is bad, otherwise there would be a ton more problems.
I would suspect the ABS module itself over the IC, just because its rare for one to fail and show no indication of doing so other than a spedometer not working.
Based on my understanding of CAN busses, the ABS module is either sending a VSS signal, or the PCM is throwing a code for not receiving one. Have you checked for any codes? It is possible that the ABS module is not testing anything wrong, but is infact not working. The only way to really tell, it to try and force it to operate. Normally all you would have to do is find a large field or dirt road and slam on the brakes until the ABS works, however since you bypassed it, figuring if it will work is a bit more difficult.
You can also inspect the wiring coming from the rear wheel sensor to make sure its not damaged.
