U0140 Code: Meaning, Symptoms, Causes & Fix

Overview

U0140 is triggered when monitoring logic identifies an issue with Lost Communication With Body Control Module affecting module-to-module CAN communication.

Symptoms

feature communication timeout
multiple warning lights at once
intermittent no-start or limp mode

Common causes

CAN bus wiring fault affecting lost communication with body control module
Network termination or gateway fault
Connector pin damage/corrosion or harness stress near related components

How to diagnose U0140

Confirm U0140 and capture freeze-frame data with a professional scan tool.
Inspect wiring, connectors, and grounds related to lost communication with body control module for obvious defects.
Check CAN high/low integrity, network termination resistance, and module wake-up status.
Check for related DTCs to identify the root-cause chain before replacing parts.
After repair, clear codes and confirm readiness monitors complete without recurrence.

Severity of code U0140

Moderate: This code is moderate severity: the vehicle may still operate, but fault progression can increase repair cost over time.

Can you drive with U0140?

Most vehicles can be driven short-term with U0140, but postpone heavy load/highway driving until repaired.

If the warning lamp is flashing or drivability/safety is affected, avoid driving and diagnose immediately.

How to fix it (step-by-step)

Repair obvious wiring/connector faults first to prevent repeat parts replacement.
Address the root fault mode (communication) in the lost communication with body control module circuit/system.
Apply the required relearn/adaptation procedure if specified by service information.
Road-test and verify U0140 remains cleared under the conditions that originally set the code.

Fix options

Repair CAN high/low wiring or termination issue.
Scan all modules for communication chain faults.
Clear DTCs and verify with live data and completed drive cycle.

Typical repair cost

$260-$1300

Common mistakes when diagnosing U0140

Replacing parts without verifying voltage, ground, and signal integrity first.
Ignoring related stored/pending codes that indicate upstream faults.
Skipping post-repair verification drive cycle and readiness checks.

U0140 in common vehicles

U0140 appears across makes such as Mazda, Subaru, Lexus, Jeep. Failure patterns differ by platform: wiring routes, software calibration, and component supplier revisions can change root cause.

Frequently asked questions

What causes U0140?

U0140 is commonly set by communication faults affecting lost communication with body control module.

How much does it cost to fix U0140?

For U0140, repair costs are typically $260-$1300 depending on exact root cause, labor rates, and part quality.

Can I clear U0140 without repair?

You can clear U0140 temporarily, but the code usually returns until the underlying fault is corrected.