AutoCodes – GMC – U3503 GMC

U3503 GMC Code - Control Module Input Power 'A' Circuit Intermittent/Erratic

Quick Answer

The vehicle control modules or sensors monitor the system voltage to verify the system voltage is within the normal operating range. Common causes include Faulty Control Module setting the code, Control Module harness is open or shorted, 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: U3503 GMC indicates Control Module Input Power 'A' Circuit Intermittent/Erratic.
Common causes: Common causes include Faulty Control Module setting the code, Control Module harness is open or shorted, 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 512

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 18, 2020

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code U3503 GMC Description

The vehicle control modules or sensors monitor the system voltage to verify the system voltage is within the normal operating range. With the ignition is ON, the Diagnostic Trouble Code (DTC) will set when the control module or sensor detects a system voltage of less than approximately 9 V for approximately 5 s.

OBDII Code U3503 GMC - Control Module Input Power 'A' Circuit Intermittent/Erratic - AutoCodes.com — U3503 GMC Code - Control Module Input Power 'A' Circuit Intermittent/Erratic

What does this mean?

What are the Possible Causes of the DTC U3503 GMC?

Faulty Control Module setting the code
Control Module harness is open or shorted
Control Module circuit poor electrical connection

How to Fix the DTC U3503 GMC?

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 U3503 GMC 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.

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Need more information on how to fix the U3503 GMC code? Get Access to Factory Service Manuals

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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 U3503 GMC Code

1. What are common symptoms of OBDII code U3503 in a GMC vehicle?

- Common symptoms include intermittent or erratic power fluctuations, engine stalling, rough idling, and an illuminated Check Engine Light.

2. What could cause the Control Module Input Power 'A' Circuit Intermittent/Erratic code in a GMC?

- Potential causes of this code include loose or corroded electrical connections, damaged wiring harnesses, a failing control module, or a faulty power supply.

3. How can I diagnose the U3503 code in my GMC?

- Diagnosing the U3503 code typically involves using a diagnostic scanner to retrieve the trouble code, inspecting the wiring and connectors for damage, and testing the power supply to the control module.

4. Can I continue driving my GMC with the U3503 trouble code?

- It is not recommended to drive your vehicle with the U3503 code present, as it can lead to performance issues, stalling, or further damage to the control module.

5. What repairs are commonly needed to fix the U3503 code in a GMC?

- Repairs may include repairing or replacing damaged wiring, cleaning or tightening electrical connections, replacing a faulty control module, or addressing any power supply issues.

6. How much does it typically cost to repair the Control Module Input Power 'A' Circuit Intermittent/Erratic issue in a GMC?

- The cost of repairs for the U3503 code can vary depending on the underlying cause and the extent of the damage, but it may range from a few hundred to a few thousand dollars.

7. Can a DIY enthusiast fix the U3503 trouble code in a GMC?

- While some simple checks and repairs like inspecting and cleaning electrical connections may be doable for a DIY enthusiast, diagnosing and repairing more complex issues related to the U3503 code may require professional expertise.

8. How long does it take to repair the U3503 code in a GMC?

- The repair time for the U3503 code can vary based on the specific issue and the expertise of the technician, but it may take anywhere from a few hours to a full day to complete the necessary repairs.

9. Will resetting the trouble codes make the U3503 code disappear permanently?

- Resetting the trouble codes may temporarily clear the Check Engine Light, but if the underlying issue causing the U3503 code is not addressed and repaired, the code is likely to reappear.

10. Is it necessary to visit a dealership for repairs related to the U3503 code in a GMC?

- While a dealership may have specialized knowledge and access to OEM parts, independent repair shops with experience in diagnosing and repairing OBDII codes like U3503 can also effectively address the issue at a potentially lower cost.