AutoCodes – Generic – U350B

U350B Code - Control Module Input Power 'C' Circuit Intermittent/Erratic

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: U350B indicates Control Module Input Power 'C' Circuit Intermittent/Erratic.
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 1,069

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 U350B 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 U350B - Control Module Input Power 'C' Circuit Intermittent/Erratic - AutoCodes.com — U350B Code - Control Module Input Power 'C' Circuit Intermittent/Erratic

What does this mean?

What are the Possible Causes of the DTC U350B?

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

How to Fix the DTC U350B?

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 U350B 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 U350B code?

Need more information on how to fix the U350B code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the U350B code diagnosed by a professional: Find a repair shop in your area

Information for Specific Makes

U350B Buick — Control Module Input Power 'C' Circuit Intermittent/Erratic
U350B Chevrolet — Control Module Input Power 'C' Circuit Intermittent/Erratic
U350B GMC — Control Module Input Power 'C' Circuit Intermittent/Erratic

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 U350B Code

1. What are the common symptoms of OBDII code U350B?

- Common symptoms include intermittent or erratic power loss to the control module, engine stalling, rough idling, and issues with acceleration.

2. What could cause the OBDII code U350B to trigger?

- The code U350B may be triggered by faulty wiring or connectors in the control module input power circuit, a failing control module, or issues with the power supply to the module.

3. How can I diagnose the cause of OBDII code U350B?

- Diagnosing code U350B involves checking the wiring and connectors in the control module power circuit, testing the power supply to the module, and inspecting the control module for any signs of damage or malfunction.

4. Can a weak battery or alternator cause code U350B to appear?

- Yes, a weak battery or alternator can potentially cause intermittent power issues that trigger code U350B. It is advisable to check the battery and charging system as part of the diagnostic process.

5. What are some repair tips for resolving OBDII code U350B?

- Repair tips may include repairing or replacing damaged wiring or connectors, replacing the control module if necessary, ensuring a stable power supply to the module, and clearing the code to see if it reoccurs.

6. Is it safe to continue driving with OBDII code U350B present?

- It is not recommended to continue driving with code U350B present, as it can lead to potential issues such as stalling or loss of engine power. It is best to address the underlying problem promptly.

7. Can extreme temperatures affect the occurrence of code U350B?

- Yes, extreme temperatures can sometimes exacerbate electrical issues, potentially leading to intermittent problems with the control module input power circuit and triggering code U350B.

8. How long does it typically take to repair OBDII code U350B?

- The repair time for code U350B can vary depending on the underlying cause. Simple fixes like reconnecting a loose wire may take a short time, while replacing a faulty control module could be more time-consuming.

9. Will resetting the OBDII system clear code U350B permanently?

- Resetting the OBDII system may temporarily clear the code U350B, but if the underlying issue is not addressed, the code is likely to reappear once the problem resurfaces.

10. Can a DIY enthusiast without advanced automotive knowledge fix OBDII code U350B?

- Depending on the specific cause of code U350B, some DIY enthusiasts may be able to address the issue by checking and repairing wiring or connectors. However, more complex issues may require professional assistance.