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 » C0049

Code C0049

Symptoms

• ABS warning light on

• Traction control warning light on

• Inconsistent braking performance

Common Causes

• Faulty wheel speed sensor

• Damaged wiring or connectors

• Malfunctioning ABS module

Glossary

ABS: Anti-lock Braking System

DTC: Diagnostic Trouble Code

Related Codes

• C0035

• C0040

Laymans terms

This code means there's a problem with one of the car's wheels. It's like when your bike wheel isn't spinning right.

Explanation

The C0049 code indicates an issue with the wheel speed sensor on one of the wheels.

Technical description

C0049 is a diagnostic trouble code (DTC) that refers to a malfunction in the wheel speed sensor circuit, which is crucial for the Anti-lock Braking System (ABS) and traction control system. This sensor monitors the speed of the wheel and sends this information to the car's computer.

Diagnosis steps

• Inspect the wheel speed sensor and its wiring for damage.

• Use an OBD-II scanner to check for additional codes.

• Test the sensor with a multimeter to ensure it's functioning correctly.

Repair procedures

• Replace the faulty wheel speed sensor.

• Repair or replace damaged wiring or connectors.

• Reprogram or replace the ABS module if necessary.

Tools required

• OBD-II scanner

• Multimeter

• Socket set

Estimated repair cost

$100 - $300

Difficulty level

Moderate

Commonly affected vehicles

• Chevrolet Malibu

• Ford Focus

• Toyota Camry

Preventive measures

• Regularly inspect wheel speed sensors.

• Keep the wheel hub area clean and free of debris.

• Perform routine vehicle maintenance checks.

Error code type

Sensor Issue

User experience recommendations

• Avoid driving at high speeds until the issue is resolved.

• Consult a professional mechanic for a thorough inspection.

Warranty information

Check your vehicle's warranty to see if sensor issues are covered.

Historical data

This code has been commonly reported in vehicles with older ABS systems.

Urgency level

Moderate – It affects braking performance, so it should be addressed soon.

Legal and safety notice

Driving with a malfunctioning ABS can increase stopping distances and affect safety.

Testing conditions

• Vehicle on a lift for wheel inspection

• Engine off and key in the 'on' position

Component location

The wheel speed sensor is located near the wheel hub assembly on each wheel.

FAQs

Q: What happens if I ignore the C0049 code?
A: Ignoring this code can lead to reduced braking performance and increased risk of accidents.

Q: Can I drive with the C0049 code?
A: It's not recommended to drive with this code as it affects the ABS and traction control systems.

Last updated: Oct 6, 2025 • Source: internal database

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