U0137 Code: Meaning, Symptoms, Causes & Fix

Overview

Symptoms

• multiple warning lights at once
• feature communication timeout
• module not responding in scan tool

Common causes

• CAN bus wiring fault affecting lost communication with trailer brake control module
• Module power/ground instability
• Connector pin damage/corrosion or harness stress near related components

How to diagnose U0137

1. Confirm U0137 and capture freeze-frame data with a professional scan tool.
2. Inspect wiring, connectors, and grounds related to lost communication with trailer brake control module for obvious defects.
3. Check CAN high/low integrity, network termination resistance, and module wake-up status.
4. Check for related DTCs to identify the root-cause chain before replacing parts.
5. After repair, clear codes and confirm readiness monitors complete without recurrence.

Severity of code U0137

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

Can you drive with U0137?

Most vehicles can be driven short-term with U0137, 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)

1. Repair obvious wiring/connector faults first to prevent repeat parts replacement.
2. Address the root fault mode (communication) in the lost communication with trailer brake control module circuit/system.
3. Apply the required relearn/adaptation procedure if specified by service information.
4. Road-test and verify U0137 remains cleared under the conditions that originally set the code.

Fix options

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

Typical repair cost

$260-$1300

Common mistakes when diagnosing U0137

• 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.

U0137 in common vehicles

U0137 appears across makes such as Ford, Toyota, Honda, Chevrolet. Failure patterns differ by platform: wiring routes, software calibration, and component supplier revisions can change root cause.

Frequently asked questions

What causes U0137?

U0137 is commonly set by communication faults affecting lost communication with trailer brake control module.

How much does it cost to fix U0137?

For U0137, repair costs are typically $260-$1300 depending on exact root cause, labor rates, and part quality.

Can I clear U0137 without repair?

You can clear U0137 temporarily, but the code usually returns until the underlying fault is corrected.

Helpful tools

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