OBD Guide

U240A

Transmission Range Control Module Chassis Expansion CAN Bus Off

U240A is an OBD-II diagnostic trouble code meaning: Transmission Range Control Module Chassis Expansion CAN Bus Off. Common causes: open or short circuit in the can bus, transmission range control module malfunction. Estimated repair cost: $56–278.

Severity
🔴 High
Can you drive?
Do not drive — repair immediately
Approx. repair cost
$56–278 (est.)

Symptoms

  • Incorrect gear shifting
  • Check Engine Light Illuminates
  • Transmission of the gearbox into emergency mode
  • Loss of some transmission functions
  • Errors in other CAN bus-related systems

Causes

  • Open or short circuit in the CAN bus
  • Transmission Range Control Module Malfunction
  • TRCM power supply problems
  • Corrosion or oxidation of connector contacts
  • Wiring harness damage

How to Fix

  1. Check the integrity of the CAN bus using a diagnostic scanner
  2. Inspect the TRCM connectors and wiring
  3. Check the power supply and ground of the module
  4. If necessary, replace the transmission range control module
  5. Repair or replacement of damaged CAN bus wires

Related codes

FAQ

What does the U240A code mean?

U240A is an OBD-II diagnostic trouble code that indicates: Transmission Range Control Module Chassis Expansion CAN Bus Off

What causes a U240A error code?

The most common causes of U240A include: Open or short circuit in the CAN bus; Transmission Range Control Module Malfunction; TRCM power supply problems; Corrosion or oxidation of connector contacts.

How do I fix a U240A diagnostic trouble code?

To fix U240A: Check the integrity of the CAN bus using a diagnostic scanner. Inspect the TRCM connectors and wiring. Check the power supply and ground of the module. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with U240A?

Do not drive — repair immediately

How much does it cost to fix U240A?

The estimated repair cost for U240A is $56–278. Actual cost depends on your vehicle, location, and labor rates.

See also: Russian version · NationStat