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 » B0042

Code B0042

Symptoms

• Airbag warning light on

• Airbag system deactivated

• Possible audible warning

Common Causes

• Faulty airbag module

• Damaged wiring or connectors

• Faulty clock spring

Glossary

Airbag Module: A device that controls the deployment of airbags in a vehicle.

Clock Spring: A spiral-wound cable in the steering wheel that maintains electrical connection while allowing the wheel to turn.

Related Codes

• B0041

• B0043

Laymans terms

This code means there's a problem with the car's airbag system, which helps keep you safe in a crash.

Explanation

The B0042 code indicates an issue with the airbag system, specifically related to the driver's side airbag circuit.

Technical description

B0042 is a diagnostic trouble code (DTC) for a fault in the driver's side airbag circuit. It may involve a malfunction in the airbag module, wiring, or connectors.

Diagnosis steps

• Check for any other related trouble codes.

• Inspect the wiring and connectors for damage.

• Test the airbag module and clock spring for faults.

Repair procedures

• Replace damaged wiring or connectors.

• Replace the faulty airbag module.

• Replace the clock spring if necessary.

Tools required

• OBD-II scanner

• Multimeter

• Screwdriver set

Estimated repair cost

$150 - $600

Difficulty level

Moderate

Commonly affected vehicles

• Chevrolet Silverado

• GMC Sierra

• Cadillac Escalade

Preventive measures

• Regularly inspect airbag system components.

• Avoid tampering with airbag wiring.

• Have the airbag system checked during routine maintenance.

Error code type

Safety System Issue

User experience recommendations

• Do not ignore the airbag warning light.

• Have the vehicle inspected by a professional as soon as possible.

Warranty information

Airbag system components may be covered under the vehicle's safety warranty.

Historical data

This code has been associated with faulty airbag systems in various vehicle models, leading to recalls and safety checks.

Urgency level

High – Airbag issues can affect safety in the event of a collision.

Legal and safety notice

Driving with a malfunctioning airbag system can be dangerous and may not comply with safety regulations.

Testing conditions

• Vehicle ignition on

• Airbag system self-check

Component location

The driver's side airbag is located in the steering wheel.

FAQs

Q: Can I drive with a B0042 code?
A: It's not recommended to drive with an airbag system fault as it may not deploy in an accident.

Q: How do I reset the airbag light?
A: The airbag light can be reset with an OBD-II scanner after the fault is repaired.

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

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