AutoCodes – Generic – C0238

C0238 Code - Wheel Speed Mismatch

Quick Answer

As the wheel spins, the wheel speed sensor produces an Alternating Current (AC) signal. Common causes include Faulty Front or Rear Speed Sensor, Front or Rear Speed Sensor harness is open or shorted, Front or Rear 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: C0238 indicates Wheel Speed Mismatch.
Common causes: Common causes include Faulty Front or Rear Speed Sensor, Front or Rear Speed Sensor harness is open or shorted, Front or Rear 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 3,885

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 May 10, 2020

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code C0238 Description

As the wheel spins, the wheel speed sensor produces an Alternating Current (AC) signal. The Electronic Brake Control Module (EBCM) uses the frequency of the AC signal to calculate the wheel speed.

OBDII Code C0238 - Wheel Speed Mismatch - AutoCodes.com — C0238 Code - Wheel Speed Mismatch

What does this mean?

What are the Possible Causes of the DTC C0238?

Faulty Front or Rear Speed Sensor
Front or Rear Speed Sensor harness is open or shorted
Front or Rear Speed Sensor circuit poor electrical connection
Faulty EBCM

How to Fix the DTC C0238?

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 C0238 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 C0238 code?

Need more information on how to fix the C0238 code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the C0238 code diagnosed by a professional: Find a repair shop in your area

Information for Specific Makes

C0238 Buick — Wheel Speed Mismatch
C0238 Cadillac — Wheel Speed Mismatch
C0238 Chevrolet — Wheel Speed Mismatch
C0238 GMC — Wheel Speed Mismatch

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 C0238 Code

1. What are the common symptoms of OBDII code C0238 (Wheel Speed Mismatch)?

- Common symptoms include the ABS light being illuminated on the dashboard, traction control system malfunctions, and potential issues with the vehicle's stability control.

2. What causes OBDII code C0238 (Wheel Speed Mismatch) to trigger?

- This code is typically triggered when the ABS system detects a discrepancy in wheel speed data from different sensors, indicating potential issues with the speed sensors, wiring, or ABS module.

3. How can I diagnose the root cause of OBDII code C0238 (Wheel Speed Mismatch)?

- Diagnosing this code often involves inspecting the wheel speed sensors, checking for any damaged wiring, testing the ABS module, and ensuring proper sensor alignment and calibration.

4. Can weather conditions affect the triggering of OBDII code C0238 (Wheel Speed Mismatch)?

- Yes, extreme weather conditions such as heavy rain, snow, or ice can sometimes interfere with the wheel speed sensors and lead to the triggering of this code.

5. Are there any DIY repair tips for addressing OBDII code C0238 (Wheel Speed Mismatch)?

- DIY repair tips may include checking and cleaning the wheel speed sensors, inspecting the wiring harness for damage, ensuring proper sensor alignment, and resetting the ABS system.

6. Is it safe to continue driving with OBDII code C0238 (Wheel Speed Mismatch) present?

- It is not recommended to continue driving with this code present, as it can affect the proper functioning of the ABS, traction control, and stability control systems, potentially compromising vehicle safety.

7. How can a mechanic reset OBDII code C0238 (Wheel Speed Mismatch)?

- A mechanic can reset this code using a diagnostic scanner capable of clearing ABS fault codes after addressing the underlying issue with the wheel speed sensors or ABS system.

8. Are there any recalls related to OBDII code C0238 (Wheel Speed Mismatch)?

- Recalls related to this specific OBDII code are rare, but it's essential to check with the vehicle manufacturer or authorized dealers for any relevant recall information.

9. Can OBDII code C0238 (Wheel Speed Mismatch) be a false alarm?

- While rare, false alarms for this code can occur due to temporary sensor malfunctions or intermittent wiring issues. It's crucial to thoroughly diagnose the problem to rule out false alarms.

10. How much does it typically cost to repair OBDII code C0238 (Wheel Speed Mismatch)?

- The cost of repairing this code can vary depending on the underlying issue, but it may involve sensor replacement, wiring repairs, or ABS module diagnostics, with potential costs ranging from $100 to $500 or more.