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 » B0118

Code B0118

Symptoms

• Airbag warning light on

• Airbags may not deploy in a crash

• Error message on dashboard

Common Causes

• Faulty side impact sensor

• Damaged wiring or connectors

• Faulty airbag control module

Glossary

OBD-II: On-Board Diagnostics, a system to monitor vehicle performance.

Sensor: A device that detects or measures a physical property.

Related Codes

• B0117

• B0120

Laymans terms

This code means there's a problem with the car's airbag system. It's like when a toy stops working because a wire inside is loose.

Explanation

B0118 indicates a fault in the airbag system's sensor circuit.

Technical description

The B0118 code is triggered when the airbag control module detects an issue with the side impact sensor circuit, which could be due to a malfunctioning sensor or a wiring problem.

Diagnosis steps

• Inspect the side impact sensor and its wiring for damage.

• Check the connectors for corrosion or loose connections.

• Use a diagnostic tool to read airbag system codes.

Repair procedures

• Replace the faulty side impact sensor.

• Repair or replace damaged wiring or connectors.

• Reset the airbag system with a diagnostic tool.

Tools required

• OBD-II scanner

• Multimeter

• Screwdriver set

Estimated repair cost

$200 - $600

Difficulty level

Moderate

Commonly affected vehicles

• Toyota Camry

• Honda Accord

• Ford Fusion

Preventive measures

• Regularly inspect airbag system components.

• Ensure wiring is not exposed to moisture.

• Schedule routine vehicle maintenance.

Error code type

Sensor Issue

User experience recommendations

• Do not ignore the airbag warning light.

• Consult a professional mechanic for diagnosis.

• Avoid driving the vehicle until the issue is resolved.

Warranty information

Airbag systems are often covered under extended warranties. Check with your vehicle manufacturer.

Historical data

This code has been associated with sensor failures in vehicles with side impact airbags since the early 2000s.

Urgency level

High – Airbag system issues can affect safety in a collision.

Legal and safety notice

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

Testing conditions

• Vehicle stationary

• Ignition in the 'on' position

Component location

The side impact sensor is typically located in the side of the vehicle, near the door or seat area.

FAQs

Q: Can I drive with a B0118 code?
A: It's not recommended, as the airbag system may not function properly.

Q: How do I reset the airbag light?
A: After repairs, use an OBD-II scanner to clear the code and reset the system.

Last updated: Apr 20, 2026 • Source: internal database

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