CHEVROLET, GMC · 2019-05-13
This Technical bulletin provides a Correction for a Condition of OnStar Red LED Illuminated - DTCs U18B4, U18B5, U18AF Set.
U18B4 · Manufacturer communications
A listed vehicle is a research lead. Confirm the engine, production range and software in the manufacturer's information.
U18B4 ← What does this code mean?2 Results
GMC · 2018-03-28
This technical bulletin provides a procedure to repair a bad terminal and re-route the harness to prevent the future event of Radio Audio Randomly Cuts Out DTC U18B4 - Lost Communication with Radio on Ethernet Bus from happening again.