AutoCodes – Generic – U3501

U3501 Code - Control Module Supply Circuit 1 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: U3501 indicates Control Module Supply Circuit 1 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 44,360

How popular is this code, among other codes? Medium

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 U3501 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 U3501 - Control Module Supply Circuit 1 Low Voltage - AutoCodes.com — U3501 Code - Control Module Supply Circuit 1 Low Voltage

What does this mean?

What are the Possible Causes of the DTC U3501?

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

How to Fix the DTC U3501?

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 U3501 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 U3501 code?

Need more information on how to fix the U3501 code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the U3501 code diagnosed by a professional: Find a repair shop in your area

Information for Specific Makes

U3501 Buick — Control Module Supply Circuit 1 Low Voltage
U3501 Cadillac — Control Module Supply Circuit 1 Low Voltage
U3501 Chevrolet — Control Module Supply Circuit 1 Low Voltage
U3501 GMC — Control Module Supply Circuit 1 Low 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 U3501 Code

1. What are the common symptoms of OBDII code U3501 (Control Module Supply Circuit 1 Low Voltage)?

The common symptoms include difficulty starting the vehicle, poor engine performance, and an illuminated check engine light.

2. What can cause the OBDII code U3501 to trigger?

The code U3501 can be triggered by issues such as a weak battery, faulty alternator, damaged wiring, or a malfunctioning control module.

3. How can I diagnose the cause of OBDII code U3501?

To diagnose the cause of U3501, you can start by checking the battery voltage, inspecting the alternator, examining the wiring for any visible damage, and using a multimeter to test the voltage levels at different points.

4. What are the possible repair options for OBDII code U3501?

Repair options for U3501 may include replacing the battery if it is weak, repairing or replacing the alternator, repairing any damaged wiring, or replacing the control module if necessary.

5. Can driving with OBDII code U3501 cause further damage to the vehicle?

Continuing to drive with U3501 can potentially cause damage to other electrical components in the vehicle due to the low voltage supply, so it is recommended to address the issue promptly.

6. How urgent is it to repair OBDII code U3501?

While the vehicle may still be operable with U3501, it is important to address the issue promptly to avoid further damage to the electrical system and ensure optimal performance.

7. Is it safe to clear the OBDII code U3501 without making repairs?

Clearing the code without addressing the underlying issue may temporarily turn off the check engine light, but the problem will likely persist and trigger the code again in the future.

8. Can a DIY enthusiast repair OBDII code U3501, or is it best left to professional mechanics?

Depending on the root cause of the issue, some DIY enthusiasts may be able to repair U3501 themselves, especially if it involves tasks like checking the battery or inspecting wiring. However, complex repairs may require professional assistance.

9. How much can I expect to pay for repairs related to OBDII code U3501?

The cost of repairs for U3501 can vary depending on the specific cause of the issue, but it may involve expenses such as battery replacement, alternator repair, wiring repairs, or control module replacement.

10. Will fixing OBDII code U3501 improve the overall performance and fuel efficiency of the vehicle?

Addressing U3501 can help improve the overall performance and fuel efficiency of the vehicle by ensuring a proper voltage supply to the control modules and electrical components.