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 » C0038

Code C0038

Symptoms

• ABS warning light on

• Inoperative ABS system

• Unusual braking behavior

Common Causes

• Faulty wheel speed sensor

• Damaged wiring or connectors

• Malfunctioning ABS control module

Glossary

ABS: Anti-lock Braking System

OBD-II: On-Board Diagnostics, Second Generation

Related Codes

• C0035

• C0040

Laymans terms

This code means that there is a problem with one of the car's wheel speed sensors. These sensors help the car know how fast each wheel is turning.

Explanation

The C0038 code indicates an issue with a wheel speed sensor, which is part of the vehicle's anti-lock braking system (ABS).

Technical description

C0038 is a chassis code related to the wheel speed sensor circuit. It typically refers to a fault in the left rear wheel speed sensor or its circuit, affecting the ABS functionality.

Diagnosis steps

• Use an OBD-II scanner to confirm the code.

• Inspect the left rear wheel speed sensor and wiring for damage.

• Test the sensor with a multimeter for proper resistance.

Repair procedures

• Replace the faulty wheel speed sensor.

• Repair or replace damaged wiring or connectors.

• Replace the ABS control module if necessary.

Tools required

• OBD-II scanner

• Multimeter

• Basic hand tools

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 ABS system clean and free of debris.

• Check wiring and connectors for wear and tear.

Error code type

Sensor Issue

User experience recommendations

• Do not ignore the ABS warning light.

• Have the braking system checked by a professional.

• Avoid hard braking until the issue is resolved.

Warranty information

Check your vehicle's warranty for coverage on ABS components.

Historical data

The C0038 code has been associated with wheel speed sensor issues since the introduction of ABS systems in vehicles.

Urgency level

Moderate – While the car can be driven, the ABS system may not function properly, affecting safety.

Legal and safety notice

Driving with a malfunctioning ABS system can increase the risk of accidents. Always ensure your vehicle's braking system is in good working order.

Testing conditions

• Vehicle stationary

• Key in the 'on' position

Component location

The wheel speed sensor is located near the wheel hub of each wheel.

FAQs

Q: What does a wheel speed sensor do?
A: A wheel speed sensor measures the speed of each wheel and sends this information to the ABS system.

Q: Can I drive with a C0038 code?
A: While you can drive, it's not recommended as the ABS may not work properly, affecting braking performance.

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

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