AutoCodes – Generic – U3506

U3506 Code - Control Module Supply Circuit 2 High 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: U3506 indicates Control Module Supply Circuit 2 High 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 1,220

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 U3506 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 U3506 - Control Module Supply Circuit 2 High Voltage - AutoCodes.com — U3506 Code - Control Module Supply Circuit 2 High Voltage

What does this mean?

What are the Possible Causes of the DTC U3506?

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

How to Fix the DTC U3506?

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 U3506 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 U3506 code?

Need more information on how to fix the U3506 code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the U3506 code diagnosed by a professional: Find a repair shop in your area

Information for Specific Makes

U3506 Buick — Control Module Supply Circuit 2 High Voltage
U3506 Cadillac — Control Module Supply Circuit 2 High Voltage
U3506 Chevrolet — Control Module Supply Circuit 2 High Voltage
U3506 GMC — Control Module Supply Circuit 2 High Voltage

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 U3506 Code

1. What are the common symptoms of OBDII code U3506 - Control Module Supply Circuit 2 High Voltage?

- Common symptoms include illuminated Check Engine light, decreased fuel efficiency, and potential issues with engine performance.

2. What could cause the OBDII code U3506 to trigger?

- The code U3506 is typically triggered by a malfunction in the control module supply circuit 2, leading to high voltage readings.

3. How can I diagnose the cause of OBDII code U3506?

- Diagnosing the cause of code U3506 involves checking the wiring and connections related to control module supply circuit 2, as well as testing the voltage levels.

4. Can a faulty battery cause the OBDII code U3506 to appear?

- Yes, a faulty or failing battery can sometimes cause high voltage readings in the control module supply circuit 2, leading to the triggering of code U3506.

5. Are there any safety concerns associated with OBDII code U3506?

- While code U3506 itself may not pose immediate safety risks, it is important to address the underlying issue promptly to prevent potential damage to other vehicle components.

6. What repair tips can help resolve OBDII code U3506?

- Repair tips for resolving code U3506 may include checking and repairing any damaged wiring, ensuring proper connections, and addressing any issues with the voltage regulator.

7. Can a DIY enthusiast fix OBDII code U3506 at home?

- Depending on the root cause of the issue, DIY enthusiasts with knowledge of automotive electrical systems may be able to address code U3506 at home.

8. Is it necessary to clear the OBDII code U3506 after completing repairs?

- Yes, it is recommended to clear the OBDII code U3506 after completing any necessary repairs to ensure that the issue has been properly resolved.

9. How urgent is it to address OBDII code U3506?

- While code U3506 may not require immediate attention if the vehicle is running normally, it is advisable to address the issue promptly to prevent potential long-term damage.

10. Can OBDII code U3506 cause the vehicle to fail an emissions test?

- Yes, unresolved issues related to code U3506 can potentially cause the vehicle to fail an emissions test due to improper control module supply circuit voltage levels.