What is an OBD2 code?

An OBD2 (On-Board Diagnostics) code is a diagnostic trouble code (DTC) generated by your vehicle's computer system when it detects a problem. These codes help identify specific issues with your vehicle's engine, transmission, emissions, or other systems.

How do I read OBD2 codes?

To read OBD2 codes, you'll need an OBD2 scanner. Plug it into your vehicle's OBD2 port (usually located under the dashboard), turn your key to the 'ON' position, and follow your scanner's instructions to retrieve the codes. Each code starts with a letter (P, B, C, or U) followed by four numbers.

What do the different types of OBD2 codes mean?

OBD2 codes are categorized by their first letter: P (Powertrain) for engine and transmission issues, B (Body) for interior systems like airbags, C (Chassis) for mechanical systems like brakes, and U (Network) for computer and module communication problems.

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Home » OBD2 Codes » U3519

Code U3519

Symptoms

• Check Engine Light is on

• Erratic vehicle behavior

• Loss of certain vehicle functions

Common Causes

• Faulty wiring or connections

• Defective control module

• Network communication issues

Glossary

OBD-II: On-Board Diagnostics, a standardized system in vehicles for self-diagnosis and reporting.

CAN bus: Controller Area Network, a robust vehicle bus standard designed to allow microcontrollers and devices to communicate with each other.

Related Codes

• U0100

• U0121

Laymans terms

This code means that the car's computer is having trouble talking to one of the other parts of the car. It's like when your phone can't connect to the internet.

Explanation

U3519 indicates a communication error between the vehicle's control modules.

Technical description

The U3519 code is a network communication error, typically involving the Controller Area Network (CAN) bus. It means one or more control modules are not able to communicate properly with each other.

Diagnosis steps

• Check for other related codes

• Inspect wiring and connections

• Test the communication network

Repair procedures

• Repair or replace damaged wiring

• Replace faulty control module

• Reprogram or update the software

Tools required

• OBD-II scanner

• Multimeter

• Wiring diagram

Estimated repair cost

$100 - $500

Difficulty level

Moderate

Commonly affected vehicles

• Ford F-150

• Chevrolet Silverado

• Toyota Camry

Preventive measures

• Regular maintenance checks

• Ensure secure connections

• Update vehicle software

Error code type

Network Communication Error

User experience recommendations

• Avoid driving if the vehicle behaves erratically

• Consult a professional mechanic

• Keep a record of the error code

Warranty information

Check with your vehicle manufacturer for warranty coverage on control modules.

Historical data

This code has been more common in vehicles with complex electronic systems and high mileage.

Urgency level

Moderate – It should be addressed soon to avoid further issues.

Legal and safety notice

Ignoring this error could lead to safety issues. Always address vehicle warnings promptly.

Testing conditions

• Vehicle in ignition on position

• All electrical systems active

Component location

The control modules are typically located throughout the vehicle, including under the dashboard and in the engine compartment.

FAQs

Q: Can I drive my car with a U3519 code?
A: It's not recommended as it may lead to erratic behavior. Get it checked as soon as possible.

Q: Will disconnecting the battery clear the U3519 code?
A: Disconnecting the battery may temporarily clear the code, but it won't fix the underlying issue.

Last updated: Oct 28, 2025 • Source: internal database

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