OBD Guide

U0299

Lost Communication With DC/DC Converter Control Module B

Severity
🔴 High
Can you drive?
Limited driving only, diagnose soon
Approx. repair cost
$167–556 (est.)

Symptoms

  • Check Engine light comes on
  • The car goes into emergency mode
  • Reduced engine power
  • Problems with charging a high-voltage battery
  • Errors in other systems related to high voltage equipment

Causes

  • Open or short circuit in the communication circuit
  • Malfunction of DC/DC converter module B
  • Connector problems or contact corrosion
  • Software error in the control unit
  • Module power problems

How to Fix

  1. Check the integrity of the wiring and connectors in the communication circuit
  2. Check the power and ground of the DC/DC converter module
  3. Scan all modules for additional errors
  4. Check or replace DC/DC converter module B
  5. Update control unit software

Related codes

Error U0299 by Vehicle Brand