OBD Guide

C0291

Lost Communications With BCM

C0291 is an OBD-II diagnostic trouble code meaning: Lost Communications With BCM. Common causes: open circuit between ecu and bcm, damaged wiring harness. Estimated repair cost: $56–167.

Severity
⚠️ Medium
Can you drive?
Limited driving only, diagnose soon
Approx. repair cost
$56–167 (est.)

Symptoms

  • Failure of body systems (lighting, power windows, central locking)
  • Inability to control body functions
  • Check engine light on

Causes

  • Open circuit between ECU and BCM
  • Damaged wiring harness
  • BCM malfunction
  • Poor fixation of connectors
  • BCM power problems

How to Fix

  1. Check the integrity of the wiring harness between the ECU and BCM
  2. Make sure the connectors are securely connected
  3. Check BCM supply voltage
  4. Test the BCM on another vehicle (if possible)
  5. Replace BCM if faulty

Related codes

Error C0291 by Vehicle Brand

FAQ

What does the C0291 code mean?

C0291 is an OBD-II diagnostic trouble code that indicates: Lost Communications With BCM

What causes a C0291 error code?

The most common causes of C0291 include: Open circuit between ECU and BCM; Damaged wiring harness; BCM malfunction; Poor fixation of connectors.

How do I fix a C0291 diagnostic trouble code?

To fix C0291: Check the integrity of the wiring harness between the ECU and BCM. Make sure the connectors are securely connected. Check BCM supply voltage. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with C0291?

Limited driving only, diagnose soon

How much does it cost to fix C0291?

The estimated repair cost for C0291 is $56–167. Actual cost depends on your vehicle, location, and labor rates.

See also: Russian version · NationStat