OBD Guide

U186B

Electronic Brake Control Module Lost Communication With Transmission Control Module

U186B is an OBD-II diagnostic trouble code meaning: Electronic Brake Control Module Lost Communication With Transmission Control Module. Common causes: broken or damaged can bus wires, poor contact in module connectors. Estimated repair cost: $56–278.

Severity
⚠️ Medium
Can you drive?
Yes, but get it checked soon
Approx. repair cost
$56–278 (est.)

Symptoms

  • Check Engine Light Is On
  • Possible problems with gear shifting
  • Disabling the stabilization system
  • Errors in other modules
  • Reduced vehicle dynamics

Causes

  • Broken or damaged CAN bus wires
  • Poor contact in module connectors
  • Malfunction of the brake control module
  • Transmission control module malfunction
  • Problems with module power supply

How to Fix

  1. Check the integrity of the CAN bus between modules
  2. Inspect connectors and contacts for corrosion and damage
  3. Check power and ground of modules
  4. Scan all modules for other errors
  5. Replace the faulty module if necessary

Related codes

FAQ

What does the U186B code mean?

U186B is an OBD-II diagnostic trouble code that indicates: Electronic Brake Control Module Lost Communication With Transmission Control Module

What causes a U186B error code?

The most common causes of U186B include: Broken or damaged CAN bus wires; Poor contact in module connectors; Malfunction of the brake control module; Transmission control module malfunction.

How do I fix a U186B diagnostic trouble code?

To fix U186B: Check the integrity of the CAN bus between modules. Inspect connectors and contacts for corrosion and damage. Check power and ground of modules. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with U186B?

Yes, but get it checked soon

How much does it cost to fix U186B?

The estimated repair cost for U186B is $56–278. Actual cost depends on your vehicle, location, and labor rates.

See also: Russian version · NationStat