01 What are some of the most rare cars in the world? • 02 Lean vs. Rich: Which Engine Problem Should You Worry About … • 03 P0105 - MAP Sensor Circuit Insufficient Activity • 04 Is it Bad to Pump Your Brakes When The Car is Off? • 05 Engineers Share the Five Minute Secret That Keeps Vehicles … • 06 How to Tell If Your Brake Booster or Master Cylinder Is Bad • 07 The Secret Role Of Oxygen Sensors And How They Quietly Wast… • 08 P0172 – System Too Rich (Bank 1): Fuel Economy Problems • 09 EXPLAINER: ENGINE IMMOBILIZER. • 10 How to Clean a Mass Air Flow Sensor •

DTC codes / U00xx · Network wiring and bus faults / U008C

U008CVehicle Communication Bus G (+) Low

U008C is a generic network communication code indicating that the vehicle's main communication bus, often called the CAN (Controller Area Network) bus, has a low voltage condition on its G (+) circuit. The computer or gateway module that monitors this bus detected that the positive side of the differential pair is being pulled low, which can disrupt data transmission between modules. This fault typically points to a wiring issue, a failed module, or a power/ground problem affecting the network.

SystemNetwork
Code typeGeneric (all makes)
SeverityHigh
Fix difficultyProfessional
AreaNetwork wiring and bus faults

Guidance is general and written for all OBD-II vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.

Running on fumes Free guides aren't free to make. Top up the tank. Any amount, one time. Fuel the Garage