AutoCodes – GMC – U3509 GMC

U3509 GMC Code - Control Module Supply Circuit 3 Low Voltage

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: U3509 GMC indicates Control Module Supply Circuit 3 Low Voltage.
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 684

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 U3509 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 U3509 GMC - Control Module Supply Circuit 3 Low Voltage - AutoCodes.com — U3509 GMC Code - Control Module Supply Circuit 3 Low Voltage

What does this mean?

What are the Possible Causes of the DTC U3509 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 U3509 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 U3509 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.

Need more information about the U3509 GMC code?

Need more information on how to fix the U3509 GMC code? Get Access to Factory Service Manuals

Need Help with the Code?

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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 U3509 GMC Code

1. What are common symptoms of OBDII code U3509 GMC (Control Module Supply Circuit 3 Low Voltage)?

- Common symptoms include engine stalling, poor acceleration, rough idle, and illuminated check engine light.

2. What can cause the OBDII code U3509 GMC to appear?

- The code may be triggered by issues such as a faulty control module, damaged wiring, or a weak battery.

3. How can I diagnose the cause of the U3509 code in my GMC vehicle?

- Use a diagnostic scanner to retrieve the code and check for any related codes. Inspect the control module, wiring, and battery connections for any visible damage.

4. What are some potential repair tips for fixing the Control Module Supply Circuit 3 Low Voltage issue?

- Start by checking and replacing the control module if necessary. Ensure all wiring connections are secure and free of corrosion. Test the battery and charging system for proper voltage output.

5. Is it safe to continue driving with the U3509 code illuminated in my GMC vehicle?

- It is not recommended to drive with the U3509 code present, as it can lead to further damage to the vehicle's components and potentially unsafe driving conditions.

6. Can a DIY enthusiast repair the U3509 code issue themselves?

- Depending on the level of expertise, DIY enthusiasts may be able to address the U3509 code by checking and repairing wiring connections, but more complex issues may require professional assistance.

7. How much does it typically cost to repair the Control Module Supply Circuit 3 Low Voltage problem in a GMC vehicle?

- The cost of repairs can vary depending on the specific cause of the issue, but it may range from a few hundred dollars for simple fixes to over a thousand dollars for more extensive repairs.

8. Will resetting the OBDII code U3509 GMC make it go away permanently?

- Resetting the code without addressing the underlying issue will only temporarily clear the check engine light. The code is likely to reappear if the root cause is not resolved.

9. Are there any preventive measures to avoid encountering the U3509 code in the future?

- Regularly check and maintain your vehicle's electrical system, including the control module and wiring connections. Ensure the battery is in good condition to prevent voltage-related issues.

10. How long does it take to repair the Control Module Supply Circuit 3 Low Voltage issue in a GMC vehicle?

- The repair time can vary depending on the complexity of the problem and the availability of parts. Simple fixes may be completed in a few hours, while more involved repairs could take a day or more.