AutoCodes – Generic – U1A4C

U1A4C Code - Build/End Of Line Mode Active

Quick Answer

This Diagnostic Trouble Code (DTC) can be set in the Driver Front Seat Module (DSM) if the seat calibration routine has not been completed successfully. Common causes include Seat calibration routine did not complete successfully, Faulty Driver Front Seat Module (DSM), Driver Front Seat Module harness is open or shorted. 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: U1A4C indicates Build/End Of Line Mode Active.
Common causes: Common causes include Seat calibration routine did not complete successfully, Faulty Driver Front Seat Module (DSM), Driver Front Seat Module harness is open or shorted.
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 11,929

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 Jun 10, 2020

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code U1A4C Description

This Diagnostic Trouble Code (DTC) can be set in the Driver Front Seat Module (DSM) if the seat calibration routine has not been completed successfully.

OBDII Code U1A4C - Build/End Of Line Mode Active - AutoCodes.com — U1A4C Code - Build/End Of Line Mode Active

What does this mean?

What are the Possible Causes of the DTC U1A4C?

Seat calibration routine did not complete successfully
Faulty Driver Front Seat Module (DSM)
Driver Front Seat Module harness is open or shorted
Driver Front Seat Module circuit poor electrical connection

How to Fix the DTC U1A4C?

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 U1A4C 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 U1A4C code?

Need more information on how to fix the U1A4C code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the U1A4C code diagnosed by a professional: Find a repair shop in your area

Information for Specific Makes

U1A4C Ford — Build/End Of Line Mode Active
U1A4C Lincoln — Build/End Of Line Mode Active
U1A4C Mercury — Build/End Of Line Mode Active

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 U1A4C Code

1. What does the OBDII code U1A4C "Build/End Of Line Mode Active" mean?

The code U1A4C indicates that the vehicle is currently in a special diagnostic mode known as Build/End Of Line Mode.

2. What are the common symptoms of U1A4C code?

Common symptoms of the U1A4C code may include the check engine light being illuminated, reduced engine performance, and potential limitations on certain vehicle functions.

3. What causes the U1A4C code to trigger?

The U1A4C code is typically triggered when the vehicle's onboard diagnostic system detects that the Build/End Of Line Mode is active, which may occur during vehicle assembly or certain diagnostic procedures.

4. Can I continue driving my vehicle with the U1A4C code present?

In most cases, it is safe to continue driving your vehicle with the U1A4C code present, especially if there are no noticeable differences in vehicle performance. However, it is recommended to have the issue addressed by a professional as soon as possible.

5. How do I diagnose and repair the U1A4C code?

Diagnosing and repairing the U1A4C code typically requires specialized diagnostic equipment and knowledge. It is recommended to take your vehicle to a qualified mechanic or dealership for proper diagnosis and repair.

6. Can I reset the U1A4C code myself?

Attempting to reset the U1A4C code without addressing the underlying issue may result in the code reappearing. It is best to have a professional diagnose and repair the problem to avoid future issues.

7. Is the U1A4C code related to emissions or safety concerns?

The U1A4C code is not directly related to emissions or safety concerns. However, it is still important to address the issue to prevent potential long-term damage to the vehicle.

8. How long does it take to fix the U1A4C code?

The time required to fix the U1A4C code can vary depending on the underlying cause. Some cases may be resolved quickly, while others may require more extensive diagnosis and repair.

9. Will the U1A4C code cause permanent damage to my vehicle?

The U1A4C code itself is unlikely to cause permanent damage to your vehicle. However, it is important to address the underlying issue promptly to prevent any potential complications.

10. Can a software update fix the U1A4C code?

In some cases, a software update provided by the vehicle manufacturer may resolve the U1A4C code issue. It is recommended to consult with a professional technician to determine the best course of action.