Speedometer only works from 65 MPH and up

There are a number of things that need to be checked before we think one of the speed sensors is the issue.

The way this works is basically the speed signal it passed through different modules before the speedometer displays this signal.

I attached the info but basically the CAB gets the rear wheel speed signal and sends it to the PCM. The PCM sends it to the speedometer where it is displayed.

The best way to find this out, is to check the PCM with a scan tool to see if it registered the vehicle speed. If it does then the issue is between the PCM and cluster, most likely the cluster. If not, then the issue is between the speed sensor, CAB, or wiring to the PCM.

Does this make sense? Do you have a scan tool and can you also check for codes?

https://www.2carpros.com/articles/checking-a-service-engine-soon-or-check-engine-light-on-or-flashing

I have a code reader but no scan tool. I think we have one at work. I also did a cluster re-calibration and just read the codes it says no codes stored in module! So I'm going to take it for a test run and I'll let you know if any thing changed. thank you

Okay. Understood but I suspect the cluster is the issue so a calibration will not correct it. The fact that you have no codes is why I am thinking the cluster is the issue. If the CAB or PCM was not getting a speed signal then it would set a code. Plus the way this acts it sounds like a circuit board on the cluster.

However, the scan tool will confirm all this. Let me what you turn up. Thanks