AutoCodes – Generic – C0502

C0502 Code - Left Front Wheel Speed Sensor Circuit Low

Quick Answer

The Anti-Lock Brake System (ABS) Module monitors the Left Front Wheel Speed Sensor. Common causes include Faulty Left Front Wheel Speed Sensor, Left Front Wheel Speed Sensor harness is open or shorted, Left Front Wheel Speed Sensor circuit poor electrical connection. Severity is High - diagnose this code as soon as possible. Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

What it means: C0502 indicates Left Front Wheel Speed Sensor Circuit Low.
Common causes: Common causes include Faulty Left Front Wheel Speed Sensor, Left Front Wheel Speed Sensor harness is open or shorted, Left Front Wheel Speed Sensor circuit poor electrical connection.
Severity: High - diagnose this code as soon as possible.
Can I drive?: Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

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Code Popularity 9,212

How popular is this code, among other codes? Low

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Advanced (Pro) (3 / 3)

What is this?

Table of contents Created and updated by William Orellana on Jul 05, 2020

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code C0502 Description

The Anti-Lock Brake System (ABS) Module monitors the Left Front Wheel Speed Sensor. The ABS Module sets the OBDII code when the Left Front Wheel Speed Sensor is not to factory specifications.

OBDII Code C0502 - Left Front Wheel Speed Sensor Circuit Low - AutoCodes.com — C0502 Code - Left Front Wheel Speed Sensor Circuit Low

What does this mean?

What are the Possible Causes of the DTC C0502?

Faulty Left Front Wheel Speed Sensor
Left Front Wheel Speed Sensor harness is open or shorted
Left Front Wheel Speed Sensor circuit poor electrical connection

How to Fix the DTC C0502?

Review the 'Possible Causes' above and visually examine the corresponding wiring harness and connectors. Check for damaged components and inspect connector pins for signs of being broken, bent, pushed out, or corroded.

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the C0502 code, it typically requires 1.0 hour of labor. Rates vary by location, vehicle, and shop. Many shops charge between $80–$150 per hour; dealerships and metro areas may be higher, independents may be lower.

Need more information about the C0502 code?

Need more information on how to fix the C0502 code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the C0502 code diagnosed by a professional: Find a repair shop in your area

Information for Specific Makes

C0502 Buick — Left Front Wheel Speed Sensor Circuit Low
C0502 Cadillac — Left Front Wheel Speed Sensor Circuit Low
C0502 Chevrolet — Left Front Wheel Speed Sensor Circuit Low
C0502 GMC — Left Front Wheel Speed Sensor Circuit Low

About the author: William Orellana is a Master Mechanic and Mechanical Engineer with over 30 years of experience diagnosing and repairing vehicles. Learn more about his background.

Frequently Asked Questions about C0502 Code

1. What are the common symptoms of OBDII code C0502 (Left Front Wheel Speed Sensor Circuit Low)?

The common symptoms include the ABS light staying illuminated on the dashboard, traction control issues, and potential difficulty braking.

2. What are the possible causes of OBDII code C0502?

Potential causes of C0502 include a faulty left front wheel speed sensor, damaged sensor wiring or connectors, corrosion in the sensor circuit, or a problem with the ABS control module.

3. How can I diagnose the cause of OBDII code C0502?

Diagnosing the issue involves visually inspecting the sensor and its wiring, checking for continuity in the circuit, and using a scan tool to monitor wheel speed sensor data for anomalies.

4. Can I still drive my vehicle with OBDII code C0502 active?

While the vehicle may still be drivable, it is not recommended to drive with an active C0502 code as it can affect the proper functioning of the ABS and traction control systems.

5. Is it safe to continue driving if the ABS light is on due to OBDII code C0502?

Driving with the ABS light on can compromise the vehicle's braking performance, especially in slippery or emergency situations. It is best to address the issue promptly.

6. How can I repair OBDII code C0502 on my own?

If you have the necessary tools and expertise, you can attempt to replace the left front wheel speed sensor yourself. Ensure to follow the manufacturer's repair procedures and clear the code after the repair.

7. Will resetting the OBDII code C0502 make it go away permanently?

Simply resetting the code without addressing the underlying issue will likely result in the code reappearing once the problem is detected again during driving.

8. How much does it typically cost to repair OBDII code C0502 at a mechanic?

The cost of repairing C0502 can vary depending on the specific cause of the issue, but it may involve labor costs for diagnosis, parts replacement, and potentially reprogramming the ABS system.

9. Can extreme weather conditions affect the occurrence of OBDII code C0502?

Extreme weather conditions, particularly those leading to moisture or corrosion, can impact the wheel speed sensor's performance and potentially trigger code C0502.

10. Is it necessary to clear the OBDII code C0502 after repairing the issue?

Yes, it is essential to clear the code after resolving the problem to reset the system and ensure that the ABS and traction control functions properly without any lingering error codes.