U12B1 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 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.
Code U12B1 Description
What are the Possible Causes of the DTC U12B1?
- 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?
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 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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Information for Specific Makes
- U12B1 Infiniti — Power Supply Voltage High
- U12B1 Nissan — Power Supply Voltage High
Frequently Asked Questions about U12B1 Code
1. What does the OBDII code U12B1 mean?
The code U12B1 indicates "Power Supply Voltage High," which means the voltage supplied to a control module has exceeded the expected range.
2. What are the common symptoms of the U12B1 code?
Symptoms may include warning lights on the dashboard, erratic electrical behavior, malfunctioning systems like the radio or HVAC, and potential drivability issues.
3. What causes the U12B1 code to appear?
This code can be caused by a faulty alternator, overcharging battery, damaged wiring, poor ground connections, or a defective control module.
4. Can a weak battery trigger the U12B1 code?
No, a weak battery typically causes low voltage issues. The U12B1 code is related to excessively high voltage.
5. How is the U12B1 code diagnosed?
A technician will use a multimeter to check battery and alternator voltage, inspect wiring and grounds, and scan for additional codes to pinpoint the issue.
6. Can driving with the U12B1 code damage my car?
Yes, high voltage can damage sensitive electronic components, so it’s important to address the issue promptly.
7. How do I fix the U12B1 code?
Common repairs include replacing a faulty alternator, fixing damaged wiring, ensuring proper grounding, or replacing a malfunctioning control module.
8. Is the U12B1 code specific to certain vehicles?
No, this code can appear on most OBDII-equipped vehicles, although the affected module or system may vary by manufacturer.
9. How much does it cost to repair the U12B1 code?
Repair costs can range from $100 to $800 or more, depending on whether the issue is wiring-related or requires replacing components like the alternator.
10. Can a software update fix the U12B1 code?
In rare cases, a software update may resolve voltage misreadings, but mechanical or electrical issues are more common causes. A professional diagnosis is recommended.
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