OBD Guide

U18B6

Lost Communication With Active Safety Control Module 1 On Chassis Expansion CAN Bus

U18B6 is an OBD-II diagnostic trouble code meaning: Lost Communication With Active Safety Control Module 1 On Chassis Expansion CAN Bus. Common causes: broken or damaged can bus wires, corrosion or poor contact in connectors. Estimated repair cost: $56–278.

Severity
🔴 High
Can you drive?
Do not drive — repair immediately
Approx. repair cost
$56–278 (est.)

Symptoms

  • Check Engine Light Is On
  • Security error message on instrument panel
  • Disabling active safety systems
  • Possible problems with ABS/ESP operation
  • Errors in other related systems

Causes

  • Broken or damaged CAN bus wires
  • Corrosion or poor contact in connectors
  • Active safety module malfunction
  • Module power problems
  • Software failures in the module

How to Fix

  1. Check the integrity of the CAN bus wiring harness
  2. Inspect and clean the electrical connectors of the module
  3. Check fuses and module power supply
  4. Diagnose the active safety module
  5. Repair only from an authorized dealer

Related codes

FAQ

What does the U18B6 code mean?

U18B6 is an OBD-II diagnostic trouble code that indicates: Lost Communication With Active Safety Control Module 1 On Chassis Expansion CAN Bus

What causes a U18B6 error code?

The most common causes of U18B6 include: Broken or damaged CAN bus wires; Corrosion or poor contact in connectors; Active safety module malfunction; Module power problems.

How do I fix a U18B6 diagnostic trouble code?

To fix U18B6: Check the integrity of the CAN bus wiring harness. Inspect and clean the electrical connectors of the module. Check fuses and module power supply. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with U18B6?

Do not drive — repair immediately

How much does it cost to fix U18B6?

The estimated repair cost for U18B6 is $56–278. Actual cost depends on your vehicle, location, and labor rates.

See also: Russian version · NationStat