AutoCodes – Generic – U1814

U1814 Code - Powertrain Wake-Up Communication Circuit

Quick Answer

The Body Control Module (BCM) activates the ignition circuit, when the ignition key is in ACC, ON or START. Common causes include Faulty Body Control Module (BCM), Body Control Module harness is open or shorted, Body Control Module circuit poor electrical connection. Severity is High - diagnose this code as soon as possible. Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

What it means: U1814 indicates Powertrain Wake-Up Communication Circuit.
Common causes: Common causes include Faulty Body Control Module (BCM), Body Control Module harness is open or shorted, Body Control Module circuit poor electrical connection.
Severity: High - diagnose this code as soon as possible.
Can I drive?: Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

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Code Popularity 2,001

How popular is this code, among other codes? Low

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Advanced (Pro) (3 / 3)

What is this?

Table of contents Created and updated by William Orellana on Jul 21, 2023

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code U1814 Description

The Body Control Module (BCM) activates the ignition circuit, when the ignition key is in ACC, ON or START. The ignition circuit wakes up the devices for serial data bus communication. The Diagnostic Trouble Code (DTC) will set when the BCM senses a short to ground on the ignition circuit.

OBDII Code U1814 - Powertrain Wake-Up Communication Circuit - AutoCodes.com — U1814 Code - Powertrain Wake-Up Communication Circuit

What does this mean?

What are the Possible Causes of the DTC U1814?

Faulty Body Control Module (BCM)
Body Control Module harness is open or shorted
Body Control Module circuit poor electrical connection

How to Fix the DTC U1814?

Review the 'Possible Causes' above and visually examine the corresponding wiring harness and connectors. Check for damaged components and inspect connector pins for signs of being broken, bent, pushed out, or corroded.

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the U1814 code, it typically requires 1.0 hour of labor. Rates vary by location, vehicle, and shop. Many shops charge between $80–$150 per hour; dealerships and metro areas may be higher, independents may be lower.

Need more information about the U1814 code?

Need more information on how to fix the U1814 code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the U1814 code diagnosed by a professional: Find a repair shop in your area

Information for Specific Makes

U1814 Buick — Powertrain Wake-Up Communication Circuit
U1814 Cadillac — Powertrain Wake-Up Communication Circuit
U1814 Chevrolet — Powertrain Wake-Up Communication Circuit
U1814 GMC — Powertrain Wake-Up Communication Circuit

About the author: William Orellana is a Master Mechanic and Mechanical Engineer with over 30 years of experience diagnosing and repairing vehicles. Learn more about his background.

Frequently Asked Questions about U1814 Code

1. What are common symptoms of OBDII code U1814?

- Common symptoms include the check engine light illuminating, difficulty starting the vehicle, and issues with the powertrain communication system.

2. What can cause the OBDII code U1814 to trigger?

- The code U1814 is typically triggered by a malfunction in the powertrain wake-up communication circuit, which can be caused by wiring issues, a faulty control module, or a communication network problem.

3. How can I diagnose the OBDII code U1814?

- Diagnosis involves using a scan tool to check for the code, inspecting the wiring and connectors in the communication circuit, and testing the control modules involved in the powertrain wake-up system.

4. Can I drive my vehicle with the OBDII code U1814 present?

- It is generally not recommended to drive with the U1814 code present, as it can indicate potential issues with the powertrain communication system that may affect the vehicle's performance and safety.

5. How serious is the OBDII code U1814?

- The U1814 code is considered moderately serious, as it pertains to the powertrain wake-up communication circuit, which is essential for proper communication between control modules in the vehicle.

6. What are some repair tips for fixing the OBDII code U1814?

- Repair tips may include checking and repairing any damaged wiring, replacing faulty control modules, resetting the code with a scan tool, and ensuring proper communication network functionality.

7. Does the OBDII code U1814 affect fuel efficiency?

- The U1814 code itself may not directly affect fuel efficiency, but underlying issues with the powertrain communication system could indirectly impact fuel efficiency if left unresolved.

8. Can a DIY enthusiast fix the OBDII code U1814?

- Depending on the root cause of the U1814 code, DIY enthusiasts with knowledge of automotive electrical systems may be able to address wiring issues or replace faulty components themselves.

9. How long does it typically take to repair the OBDII code U1814?

- Repair times can vary based on the specific cause of the U1814 code, but simple fixes like repairing wiring may take a few hours, while more complex issues could require professional diagnosis and repair.

10. Is it necessary to clear the OBDII code U1814 after making repairs?

- Yes, it is important to clear the U1814 code using a scan tool after addressing the underlying issue to reset the system and ensure the check engine light does not illuminate again due to the same problem.