AutoCodes – Infiniti – U12B1 Infiniti

U12B1 Infiniti Code - Power Supply Voltage High

Quick Answer

The Diagnostic Trouble Code (DTC) sets when the Audio and Video (AV) Control Unit supply voltage exceeds upper limits. Common causes include Faulty Audio and Video (AV) Control Unit, AV Control Unit harness is open or shorted, AV Control Unit 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: U12B1 Infiniti indicates Power Supply Voltage High.
Common causes: Common causes include Faulty Audio and Video (AV) Control Unit, AV Control Unit harness is open or shorted, AV Control Unit 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 653

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 May 16, 2020

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code U12B1 Infiniti Description

The Diagnostic Trouble Code (DTC) sets when the Audio and Video (AV) Control Unit supply voltage exceeds upper limits.

OBDII Code U12B1 Infiniti - Power Supply Voltage High - AutoCodes.com — U12B1 Infiniti Code - Power Supply Voltage High

What does this mean?

What are the Possible Causes of the DTC U12B1 Infiniti?

Faulty Audio and Video (AV) Control Unit
AV Control Unit harness is open or shorted
AV Control Unit circuit poor electrical connection

How to Fix the DTC U12B1 Infiniti?

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 U12B1 Infiniti 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 U12B1 Infiniti code?

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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 U12B1 Infiniti Code

1. What does the OBDII code U12B1 mean on an Infiniti?

The U12B1 code indicates a "Power Supply Voltage High" issue, meaning the voltage powering certain modules is higher than the specified range.

2. What are the common symptoms of a U12B1 code in an Infiniti?

Symptoms may include warning lights on the dashboard, erratic behavior of electrical systems, or intermittent loss of communication between control modules.

3. What causes the U12B1 code to appear in an Infiniti?

Common causes include a faulty alternator output, a defective voltage regulator, damaged wiring, or poor ground connections.

4. Can a faulty battery cause the U12B1 code in an Infiniti?

Yes, a failing battery or incorrect battery installation may lead to voltage irregularities and trigger the code.

5. How do I diagnose the U12B1 code in my Infiniti?

Start by checking the battery voltage, alternator output, and inspecting the wiring and ground connections for damage or corrosion.

6. Is it safe to drive an Infiniti with a U12B1 code?

Driving with this code is not recommended, as excessive voltage can damage sensitive electrical components and lead to further issues.

7. How do I fix the U12B1 code on my Infiniti?

Repairs may include replacing a faulty alternator, fixing damaged wiring, cleaning or repairing ground connections, or replacing the voltage regulator.

8. How much does it cost to repair the U12B1 code on an Infiniti?

Repair costs vary depending on the issue, but alternator replacement typically ranges from $300 to $800, while wiring repairs may cost less.

9. Can a software update fix the U12B1 code in an Infiniti?

In rare cases, a software update for the vehicle's control modules may be required, but this is usually secondary to fixing hardware issues.

10. How do I prevent the U12B1 code from occurring again in my Infiniti?

Regularly maintain your battery and charging system, ensure proper installation of electrical components, and check for wiring or ground issues during routine inspections.