OBD Guide

U0079

Control Module Communication Bus G Off

U0079 is an OBD-II diagnostic trouble code meaning: Control Module Communication Bus G Off. Common causes: broken or damaged communication bus wires, short circuit in the circuit. Estimated repair cost: $6–56.

Severity
⚠️ Medium
Can you drive?
Yes, but get it checked soon
Approx. repair cost
$6–56 (est.)

Symptoms

  • Check Engine light comes on
  • Malfunction of related systems (for example, climate control, audio system)
  • Lost communication with one or more modules
  • Unstable operation of the dashboard

Causes

  • Broken or damaged communication bus wires
  • Short circuit in the circuit
  • Malfunction of one of the electronic modules
  • Poor contact in connectors
  • Problems with module power supply

How to Fix

  1. Check the integrity of the communication bus wiring
  2. Inspect connectors for oxidation or damage
  3. Check power supply of connected modules
  4. Read error codes of all modules for accurate diagnostics
  5. If necessary, replace damaged components

Related codes

Error U0079 by Vehicle Brand

FAQ

What does the U0079 code mean?

U0079 is an OBD-II diagnostic trouble code that indicates: Control Module Communication Bus G Off

What causes a U0079 error code?

The most common causes of U0079 include: Broken or damaged communication bus wires; Short circuit in the circuit; Malfunction of one of the electronic modules; Poor contact in connectors.

How do I fix a U0079 diagnostic trouble code?

To fix U0079: Check the integrity of the communication bus wiring. Inspect connectors for oxidation or damage. Check power supply of connected modules. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with U0079?

Yes, but get it checked soon

How much does it cost to fix U0079?

The estimated repair cost for U0079 is $6–56. Actual cost depends on your vehicle, location, and labor rates.

See also: Russian version · NationStat