OBD Guide

U1900

CAN Communication Bus Fault

U1900 is an OBD-II diagnostic trouble code meaning: CAN Communication Bus Fault. Common causes: broken or damaged can bus wires, short circuit in can circuit. Estimated repair cost: $6–111.

Severity
🔴 High
Can you drive?
Limited driving only, diagnose soon
Approx. repair cost
$6–111 (est.)

Symptoms

  • Check Engine light comes on
  • Incorrect operation of various vehicle systems
  • Dips in engine power
  • Disabling certain features (such as cruise control)
  • Errors in the operation of the dashboard

Causes

  • Broken or damaged CAN bus wires
  • Short circuit in CAN circuit
  • Malfunction of one of the electronic control units
  • Poor contact in CAN bus connectors
  • Problems with power supply to one of the modules

How to Fix

  1. Check the integrity of the CAN bus wiring
  2. Inspect connectors and contacts for oxidation
  3. Check power supply of all connected modules
  4. Scan all control units for errors
  5. If necessary, replace damaged wires or faulty modules

Related codes

FAQ

What does the U1900 code mean?

U1900 is an OBD-II diagnostic trouble code that indicates: CAN Communication Bus Fault

What causes a U1900 error code?

The most common causes of U1900 include: Broken or damaged CAN bus wires; Short circuit in CAN circuit; Malfunction of one of the electronic control units; Poor contact in CAN bus connectors.

How do I fix a U1900 diagnostic trouble code?

To fix U1900: Check the integrity of the CAN bus wiring. Inspect connectors and contacts for oxidation. Check power supply of all connected modules. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with U1900?

Limited driving only, diagnose soon

How much does it cost to fix U1900?

The estimated repair cost for U1900 is $6–111. Actual cost depends on your vehicle, location, and labor rates.

See also: Russian version · NationStat