AutoCodes – GMC – U350B GMC

U350B GMC 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 GMC 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 662

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

What does this mean?

What are the Possible Causes of the DTC U350B GMC?

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 GMC?

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 GMC 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.

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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 U350B GMC Code

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

Symptoms may include intermittent or erratic power loss to control modules, issues with starting the vehicle, and sporadic warning lights on the dashboard.

2. What can cause the U350B GMC code to appear?

Potential causes include faulty wiring or connectors in the control module input power circuit, a malfunctioning control module, or a weak battery.

3. How can I diagnose the Control Module Input Power 'C' Circuit issue?

The issue can be diagnosed using a scan tool to read the trouble code, followed by a visual inspection of the wiring and connectors related to the control module power circuit.

4. Can a weak battery trigger the U350B GMC code?

Yes, a weak or failing battery can cause voltage fluctuations in the control module power circuit, leading to the intermittent/erratic behavior associated with the code.

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

Repair tips include checking and repairing any damaged wiring or connectors, ensuring a strong and stable power supply to the control modules, and replacing any faulty control modules if necessary.

6. Is it safe to drive with the U350B GMC trouble code present?

It is not recommended to drive the vehicle with this code present, as it can lead to unpredictable behavior and potential safety hazards due to power loss to critical control modules.

7. Can resetting the trouble code make it go away permanently?

Resetting the trouble code may temporarily clear it, but if the underlying issue causing the code is not addressed, it is likely to reappear once the problem resurfaces.

8. How much does it typically cost to repair the U350B GMC code?

The cost of repair can vary depending on the specific cause of the code, but it may involve expenses related to parts replacement, wiring repairs, or control module reprogramming.

9. Will the U350B GMC code cause a vehicle to fail an emissions test?

Yes, if the code triggers the malfunction indicator light (MIL) or check engine light, the vehicle is likely to fail an emissions test until the issue is resolved and the code is cleared.

10. Can a DIY enthusiast fix the U350B GMC code issue?

While some basic troubleshooting steps can be performed by a DIY enthusiast, resolving the U350B GMC code may require advanced diagnostic tools and expertise, making professional assistance advisable in many cases.