U0073 code, speedometer problem, wheel speed sensors

[Jaaaaay211]

Hello, I've found alot of useful information on this site over the years for my truck just by searching the forums. But I've run into a problem that is causing me to pull my hair out and make my first post!

 

I recently bought a 2008 Silverado, so its complete history is not available to me, what I know about it is in my signature. I added the Diablo tuner to disable AFM. 

 

I'm currently getting two codes from the EBCM, u0073  (Control Module Communication Bus 'A' Off) , and c0245 (Wheel Speed Sensor Frequency Error). No codes in the ECM, or MIL.

 

The problem I'm currently having:

• Speedometer is slower than actual speed by 5-10mph as speed increases (ie, 35 is 40, but 55 is 65)
  • My Scanner shows that the front (L and R) wheel speed sensors are reading the correct speed and are within 1MPH of each other at all times - verified by GPS speedometer
• ABS light kicks on after driving down the road after each ignition cycle throwing the C0245 code.
  • Condition for setting the C0245 code: 
    • The ignition is ON.
    • Ignition voltage is greater than 9.5 volts.
    • No wheel speed sensor faults exist.
    • Brake is not applied.
    • Vehicle is not cornering.
    • No wheel spinning is detected.
• Occasional low speed ABS activation, (until the ABS light kicks on and disables ABS)

 

 

The things I have done to attempt to fix it:

• Quick visual to confirm no broken wires
• New Vehicle Speed Sensor (scanner shows that VSS is reading the same as what the speedometer is showing)
• Checked all fuses
• Cleaned up EBCM ground

 

What I think is happening is that the ECM or ECBM is reading the mismatch between the front two wheel speed sensors and the VSS and disabling the ABS? Its a non JL4 truck, so it doesn't have wheel speed sensors on each rear wheel, just the one on the transfer case that is the VSS. 

 

The U0073 code I'm completely lost on, my scanner connects to all modules, EBCM, ECM, and SRS fine as far as I can tell. I don't have a fancy Snap-On scanner or anything, just one of the Chinese ones from Amazon that reads all modules. 

 

If you have managed to read this far I appreciate it and any help you might be able to offer!