U007D 2018 GMC Sierra Code - Control Module Communication Low Speed Extension CAN Bus Off

The U007D code indicates a communication issue on the Low-Speed CAN bus, where a control module has gone "bus off" and is unable to communicate with other modules.

Common symptoms include warning lights on the dashboard, such as the check engine light, malfunctioning electronic features, or intermittent or complete loss of communication with certain vehicle systems.

Potential causes include damaged or corroded wiring, a faulty control module, a poor connection in the CAN bus network, or a short circuit in the communication lines.

It depends on the severity of the issue. If critical systems like braking or steering are affected, it’s unsafe to drive. Otherwise, the vehicle may still operate but with limited functionality.

Start by inspecting the wiring and connectors for damage or corrosion. Use a scan tool to check for additional codes and verify communication between control modules.

Yes, a weak or discharged battery can lead to communication issues on the CAN bus, potentially triggering the U007D code.

Repairs may include fixing or replacing damaged wiring, cleaning corroded connectors, reprogramming or replacing a faulty module, or addressing electrical shorts.

Repair costs vary depending on the root cause but can range from $100 for minor wiring repairs to $1,000 or more if a control module needs replacement.

The code may clear temporarily if the issue is intermittent, but it will likely return unless the underlying problem is repaired.

A professional-grade OBDII scanner capable of reading CAN bus data, a multimeter for checking voltage and continuity, and wiring diagrams for the vehicle are essential tools.