AutoCodes – Buick – U3509 Buick

U3509 Buick 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 Buick 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 673

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

What does this mean?

What are the Possible Causes of the DTC U3509 Buick?

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 Buick?

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 Buick 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 Buick code?

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

Need Help with the Code?

Get the U3509 Buick code diagnosed by a professional: Find a repair shop in your area

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 Buick Code

1. What are the common symptoms of OBDII code U3509 in a Buick related to Control Module Supply Circuit 3 Low Voltage?

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

2. What are the possible causes of the U3509 code indicating Control Module Supply Circuit 3 Low Voltage in a Buick?

- Possible causes include a faulty control module, damaged wiring or connectors, a weak battery, or a malfunctioning voltage regulator.

3. How can I diagnose the U3509 code for Control Module Supply Circuit 3 Low Voltage in my Buick?

- Diagnose by checking the battery voltage, inspecting the wiring and connectors for damage, and testing the voltage regulator and control module.

4. Can driving with the U3509 code present cause any further damage to my Buick?

- Continuing to drive with the U3509 code may lead to reduced fuel efficiency, potential stalling, or damage to other electrical components.

5. How can I repair the Control Module Supply Circuit 3 Low Voltage issue causing the U3509 code in my Buick?

- Repair options include replacing the control module, repairing or replacing damaged wiring, ensuring a strong battery connection, or replacing the voltage regulator.

6. Is it safe to drive my Buick with the U3509 code for Control Module Supply Circuit 3 Low Voltage active?

- It is not recommended to drive your Buick with the U3509 code active as it can cause performance issues and potential stalling.

7. Will resetting the OBDII code U3509 in my Buick make the issue go away permanently?

- Resetting the code may clear the check engine light temporarily, but if the underlying issue causing the code is not addressed, it will likely return.

8. How much can I expect to pay to repair the U3509 code related to Control Module Supply Circuit 3 Low Voltage in my Buick?

- Repair costs can vary depending on the exact cause of the issue, but expect to pay anywhere from $100 to $500 for parts and labor.

9. Can a DIY enthusiast with basic automotive knowledge repair the U3509 code on a Buick themselves?

- Depending on the specific cause, a DIY enthusiast may be able to repair the U3509 code with the proper tools and guidance, but complex issues may require professional assistance.

10. How urgent is it to address the U3509 code indicating Control Module Supply Circuit 3 Low Voltage in my Buick?

- It is recommended to address the U3509 code promptly to prevent potential engine performance issues and further damage to electrical components in your Buick.