Action Taken When the DTC Sets
WARNING: This page is about a different car, the 2017 GMC Acadia. However, it is still accessible from the selected car via links, so may be relevant.
- Some or all of the infotainment system audio and displays may be inoperative.
- While a current U0028 is set, the Radio will continually send 400 ms low pulses on the MOST control circuit every 2.5 s. This is a Ring Break Diagnostic indication to the devices on the ring to report a Surrogate Master Upstream Position Node.