OBD Guide

U0240

Lost Communication With Entrapment Control Module B

U0240 is an OBD-II diagnostic trouble code meaning: Lost Communication With Entrapment Control Module B. Common causes: open or short circuit in can circuit, hold control module b malfunction. Estimated repair cost: $56–167.

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

Symptoms

  • Power windows or sunroof do not work
  • Error message on the dashboard
  • Incorrect operation of comfort systems
  • Disabling related security features
  • Check Engine light comes on

Causes

  • Open or short circuit in CAN circuit
  • Hold Control Module B Malfunction
  • Module power problems
  • Corrosion of connectors
  • Software error in the module

How to Fix

  1. Check the integrity of the CAN bus wiring harness
  2. Diagnose power supply of hold control module B
  3. Inspect and clean module connectors
  4. Check module functionality
  5. Update module software
  6. Repair only from an authorized dealer

Related codes

Error U0240 by Vehicle Brand

FAQ

What does the U0240 code mean?

U0240 is an OBD-II diagnostic trouble code that indicates: Lost Communication With Entrapment Control Module B

What causes a U0240 error code?

The most common causes of U0240 include: Open or short circuit in CAN circuit; Hold Control Module B Malfunction; Module power problems; Corrosion of connectors.

How do I fix a U0240 diagnostic trouble code?

To fix U0240: Check the integrity of the CAN bus wiring harness. Diagnose power supply of hold control module B. Inspect and clean module connectors. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with U0240?

Limited driving only, diagnose soon

How much does it cost to fix U0240?

The estimated repair cost for U0240 is $56–167. Actual cost depends on your vehicle, location, and labor rates.

See also: Russian version · NationStat