AutoCodes – Cadillac – U3509 Cadillac

U3509 Cadillac 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 Cadillac 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 594

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

What does this mean?

What are the Possible Causes of the DTC U3509 Cadillac?

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 Cadillac?

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 Cadillac 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 Cadillac code?

Need more information on how to fix the U3509 Cadillac 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 U3509 Cadillac Code

1. What are the common symptoms of OBDII code U3509 in a Cadillac?

- Common symptoms include engine stalling, rough idling, poor fuel efficiency, and illuminated check engine light.

2. What does the U3509 code "Control Module Supply Circuit 3 Low Voltage" mean in a Cadillac?

- The code indicates that there is a low voltage condition detected in the Control Module Supply Circuit 3 of the vehicle.

3. What are some possible causes of the U3509 code in a Cadillac?

- Possible causes include a faulty control module, damaged wiring or connectors, a weak battery, or a failing alternator.

4. How can I diagnose the U3509 code in my Cadillac?

- Diagnosing the code usually involves checking the voltage levels in the control module supply circuit, inspecting the wiring for damage, and testing the battery and alternator.

5. Can I still drive my Cadillac with the U3509 code present?

- It is not recommended to drive the vehicle with the U3509 code present, as it can lead to further electrical issues and potential damage to the vehicle.

6. How serious is the U3509 code in a Cadillac?

- The U3509 code should be addressed promptly, as it can affect the vehicle's performance and may lead to other electrical problems if left unresolved.

7. How can I repair the U3509 code in my Cadillac?

- Repairing the code may involve replacing the faulty control module, repairing or replacing damaged wiring, ensuring a strong battery connection, or addressing any alternator issues.

8. Can I reset the U3509 code in my Cadillac with a simple OBDII scanner?

- While you can clear the code with an OBDII scanner, it is important to address the underlying issue causing the code to prevent it from reoccurring.

9. Are there any DIY fixes for the U3509 code in a Cadillac?

- DIY fixes may include checking and tightening the battery connections, inspecting the wiring for visible damage, or cleaning any corroded terminals.

10. How much does it cost to repair the U3509 code in a Cadillac?

- The cost of repairing the U3509 code can vary depending on the specific issue causing the code, but it may range from a few hundred to a few thousand dollars, including parts and labor.