OBD Guide

U0012

Medium Speed CAN Communication Bus (+) Open

U0012 is an OBD-II diagnostic trouble code meaning: Medium Speed CAN Communication Bus (+) Open. Common causes: wire break in the positive line of the can bus, connector damage or corrosion. Estimated repair cost: $6–33.

Severity
⚠️ Medium
Can you drive?
Yes, but get it checked soon
Approx. repair cost
$6–33 (est.)

Symptoms

  • Malfunctions in the operation of various vehicle systems
  • Check Engine Light Is On
  • Lost connection with some modules
  • Unstable operation of the dashboard

Causes

  • Wire break in the positive line of the CAN bus
  • Connector damage or corrosion
  • Problems with modules connected to the CAN bus
  • Wiring harness fault
  • Power or grounding problems

How to Fix

  1. Check the integrity of the positive line of the CAN bus
  2. Inspect connectors and contacts for damage or corrosion
  3. Check modules connected to the CAN bus
  4. Check wiring harness for damage
  5. Check power supply and grounding of modules

Related codes

Error U0012 by Vehicle Brand

FAQ

What does the U0012 code mean?

U0012 is an OBD-II diagnostic trouble code that indicates: Medium Speed CAN Communication Bus (+) Open

What causes a U0012 error code?

The most common causes of U0012 include: Wire break in the positive line of the CAN bus; Connector damage or corrosion; Problems with modules connected to the CAN bus; Wiring harness fault.

How do I fix a U0012 diagnostic trouble code?

To fix U0012: Check the integrity of the positive line of the CAN bus. Inspect connectors and contacts for damage or corrosion. Check modules connected to the CAN bus. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with U0012?

Yes, but get it checked soon

How much does it cost to fix U0012?

The estimated repair cost for U0012 is $6–33. Actual cost depends on your vehicle, location, and labor rates.

See also: Russian version · NationStat