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 » B0091

Code B0091

Symptoms

• Airbag warning light is on

• Airbags may not deploy in an accident

• Error message on dashboard

Common Causes

• Faulty airbag sensor

• Damaged wiring or connectors

• Malfunctioning airbag control module

Glossary

Airbag: A safety device in vehicles designed to inflate rapidly during a collision to protect passengers.

OBD-II: On-Board Diagnostics, a standardized system for diagnosing vehicle issues.

Related Codes

• B0090

• B0092

Laymans terms

This code means there's a problem with the airbag system in your car. It's like when a safety feature in a video game isn't working right.

Explanation

B0091 is a diagnostic trouble code indicating an issue with the airbag system, specifically related to a sensor or circuit malfunction.

Technical description

The B0091 code is triggered when the airbag control module detects a fault in the airbag sensor or circuit. This could be due to a malfunctioning sensor, a wiring issue, or a problem with the airbag control unit itself.

Diagnosis steps

• Use an OBD-II scanner to read the code

• Inspect airbag sensors and wiring

• Test the airbag control module

Repair procedures

• Replace faulty airbag sensor

• Repair or replace damaged wiring

• Replace airbag control module if necessary

Tools required

• OBD-II scanner

• Multimeter

• Basic hand tools

Estimated repair cost

$150 - $600

Difficulty level

Moderate

Commonly affected vehicles

• Toyota Camry

• Honda Accord

• Ford F-150

Preventive measures

• Regularly inspect airbag system

• Avoid water damage to vehicle electronics

• Perform routine maintenance checks

Error code type

Safety System Issue

User experience recommendations

• Do not ignore the airbag warning light

• Have the system checked by a professional

• Avoid DIY repairs if unsure

Warranty information

Airbag system repairs may be covered under vehicle safety warranties.

Historical data

This code has been associated with airbag system recalls and safety notices in the past.

Urgency level

High – Airbag system issues can compromise vehicle safety.

Legal and safety notice

Driving with a malfunctioning airbag system may violate safety regulations and increase the risk of injury in an accident.

Testing conditions

• Vehicle ignition on

• Airbag system self-test initiated

Component location

Airbag sensors are typically located in the front of the vehicle, near the bumper or in the passenger compartment.

FAQs

Q: Can I drive with a B0091 code?
A: It's not recommended, as the airbag system may not function properly in an accident.

Q: How do I reset the airbag light?
A: The airbag light can be reset by fixing the underlying issue and using an OBD-II scanner to clear the code.

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

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