U0299 critical

Lost Communication With Central Gateway Module

The U0299 code means the vehicle's onboard diagnostic system has detected: Lost Communication With Central Gateway Module. This is a critical severity code.

My Garage →
Keep driving?
Short distances only
DIY difficulty
hard
Estimated cost
$300 - $1,500 (parts and labor)
Diagnose CAN Bus Issues
LAUNCH CRP123X Full System Scanner

Network codes mean modules are not communicating. You need a scanner that reads all systems to find the problem.

Check Price on Amazon

Affiliate link -- we earn a commission at no extra cost to you.

Common Symptoms

  • Multiple communication codes stored
  • Several systems not communicating
  • Intermittent warning lights across dash
  • Scan tool showing multiple module losses
  • Vehicle systems randomly dropping out

Probable Causes (Ranked by Likelihood)

  • Failed central gateway module Very High
  • CAN bus backbone wiring damage High
  • Gateway module power supply issue Moderate
  • Water intrusion in gateway module area Low

Step-by-Step Diagnostic Procedure

  1. Scan gateway module for all stored codes

  2. Check gateway module power and ground

  3. Inspect CAN bus backbone wiring

  4. Look for water damage near gateway module

Frequently Asked Questions

Can I drive with U0299?

Only short distances to a repair shop. Multiple systems may be affected.

What causes U0299?

Usually a failed central gateway module. This module routes communication between all vehicle networks.

Is U0299 serious?

Yes. The gateway is the central hub for vehicle communications. Many systems depend on it.

Sources

This page is built from documented references. Verify against your own service info before repair work.

Explore More

Was this helpful?

Share carcodefinder.com with a friend who needs to decode their check engine light.