OBD Guide

U18AD

Transmission Range Control Module Lost Communication With Electronic Brake Control Module On Chassis Expansion CAN Bus

U18AD is an OBD-II diagnostic trouble code meaning: Transmission Range Control Module Lost Communication With Electronic Brake Control Module On Chassis Expansion CAN Bus. Common causes: broken or damaged can bus wires, poor contact in module 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
  • The car goes into emergency mode
  • Incorrect operation of the gearbox
  • Problems with the braking system
  • Loss of engine power

Causes

  • Broken or damaged CAN bus wires
  • Poor contact in module connectors
  • Transmission control module (TRCM) malfunction
  • Electronic Brake Control Module (EBCM) malfunction
  • Problems with module power supply

How to Fix

  1. Check the integrity of the CAN bus wiring
  2. Inspect and clean contacts in TRCM and EBCM connectors
  3. Check power supply of modules
  4. Scan modules for errors
  5. If necessary, replace faulty modules

Related codes

FAQ

What does the U18AD code mean?

U18AD is an OBD-II diagnostic trouble code that indicates: Transmission Range Control Module Lost Communication With Electronic Brake Control Module On Chassis Expansion CAN Bus

What causes a U18AD error code?

The most common causes of U18AD include: Broken or damaged CAN bus wires; Poor contact in module connectors; Transmission control module (TRCM) malfunction; Electronic Brake Control Module (EBCM) malfunction.

How do I fix a U18AD diagnostic trouble code?

To fix U18AD: Check the integrity of the CAN bus wiring. Inspect and clean contacts in TRCM and EBCM connectors. Check power supply of modules. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with U18AD?

Do not drive — repair immediately

How much does it cost to fix U18AD?

The estimated repair cost for U18AD is $56–278. Actual cost depends on your vehicle, location, and labor rates.

See also: Russian version · NationStat