OBD Guide

U18CF

Lost Communication With Active Safety Control Module 1 On High Speed CAN Bus

U18CF is an OBD-II diagnostic trouble code meaning: Lost Communication With Active Safety Control Module 1 On High Speed CAN Bus. Common causes: open or short circuit in the can bus, active safety module malfunction. Estimated repair cost: $56–222.

Severity
🔴 High
Can you drive?
Do not drive — repair immediately
Approx. repair cost
$56–222 (est.)

Symptoms

  • Check Engine Light Is On
  • Disabling active safety systems
  • Errors in other CAN bus-related systems
  • Problems with ABS/ESP operation
  • Reduced functionality of driving assistants

Causes

  • Open or short circuit in the CAN bus
  • Active safety module malfunction
  • Module power problems
  • Corrosion or oxidation of contacts
  • Software error in the module

How to Fix

  1. Check the integrity of the CAN bus and contacts
  2. Diagnose the active safety module
  3. Check power supply and grounding of the module
  4. Update the module firmware if necessary
  5. Repair only from an authorized dealer

Related codes

FAQ

What does the U18CF code mean?

U18CF is an OBD-II diagnostic trouble code that indicates: Lost Communication With Active Safety Control Module 1 On High Speed CAN Bus

What causes a U18CF error code?

The most common causes of U18CF include: Open or short circuit in the CAN bus; Active safety module malfunction; Module power problems; Corrosion or oxidation of contacts.

How do I fix a U18CF diagnostic trouble code?

To fix U18CF: Check the integrity of the CAN bus and contacts. Diagnose the active safety module. Check power supply and grounding of the module. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with U18CF?

Do not drive — repair immediately

How much does it cost to fix U18CF?

The estimated repair cost for U18CF is $56–222. Actual cost depends on your vehicle, location, and labor rates.

See also: Russian version · NationStat