GMC Code P1381 – Misfire Detected – No Communication with Brake Control Module

P1381 GMC Code: Misfire and Brake Control Module Communication Issue

The diagnostic code P1381 for GMC vehicles indicates that a misfire has been detected, accompanied by a lack of communication between the engine control module (ECM) and the brake control module. This issue can cause irregular engine operation, reduce vehicle performance, and affect fuel efficiency. If this code is not addressed promptly, it may lead to more serious mechanical problems.

Common Causes of P1381 GMC Code

Note: This list is not exhaustive, and other causes may also be responsible for this issue.

• Faulty wiring or connectors between the ECM and the brake control module.
• Malfunction of the ECM or the brake control module.
• Error or interruption in the vehicle’s communication network.
• Corrosion or damage to electrical components.
• Software issues within the vehicle’s management systems.

Symptoms of P1381 GMC Code

• Engine misfires or irregular operation.
• Reduced engine performance.
• Hesitation or jerking during acceleration.
• Increased fuel consumption.
• Illumination of the Check Engine light.

Steps to Resolve P1381 GMC Code

1. Initial Diagnosis: Use a diagnostic tool to confirm the P1381 code and identify the affected components or systems.
2. Inspect Wiring and Connections: Check the connections between the ECM and the brake control module for any faults, damage, or poor connections. Repair or replace as necessary.
3. Check Electrical Components: Inspect components related to the system for corrosion, wear, or damage. Clean or replace affected parts.
4. Module Analysis: Test the ECM and brake control module for any malfunctions. If either module is faulty, replace or reprogram it as needed.
5. Software Update: Check for available software updates for the ECM or brake module and apply them to resolve any communication issues.
6. Reset and Road Test: Clear the error codes, reset the ECM, and then perform a road test to verify that the issue has been resolved and the vehicle is operating normally.

By following these steps, you can effectively address the P1381 code and restore optimal engine and brake system performance. If the problem persists, consult a qualified technician for further assistance.