AutoCodes.com | All About OBDII Engine Codes
AutoCodes - Generic - C0638

C0638 Code - Left Front Normal Force Circuit High

- Code Popularity: 1,977 Views
- Repair Importance Level: 3/3
- Repair Difficulty Level: 3/3
Table of contents
Share on Facebook   Share on Twitter   Share on Linkedin

What are the Possible Causes of the DTC C0638?

NOTE: The causes shown may not be a complete list of all potential problems, and it is possible that there may be other causes.
  • Faulty Electronic Brake Control module (EBCM)
  • Electronic Brake Control module (EBCM) harness is open or shorted
  • Electronic Brake Control module (EBCM) circuit poor electrical connection
⚠ Does your Car have Safety Recalls? → Check here

How to Fix the DTC C0638?

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

Search for C0638 Questions and Answers: Search here →

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the C0638 code, it typically requires 1.0 hour of labor. The specific diagnosis time and labor rates at auto repair shops can differ based on factors such as the location, make and model of the vehicle, and even the engine type. It is common for most auto repair shops to charge between $75 and $150 per hour.

What are Code Possible Symptoms?

  • Anti-Lock Brake System (ABS) Warning Light ON
  • Engine Light ON (or Service Engine Soon Warning Light)

Code C0638 Description

The Continuously Variable Road Sensing Suspension (CVRSS) module estimates the road surface and communicates that information to the Electronic Brake Control module (EBCM). The CVRSS module provides a Pulse Width Modulation (PWM) signal to the EBCM through the left and right normal force signal circuits. The CVRSS module sends each normal force value twice to the EBCM. The possible values of the PWM duty cycle are 20%, 40%, 60% and 80%, with the valid range from 10-90%. The EBCM uses this information to provide improved rough-road braking performance.

OBDII Code C0638 - Left Front Normal Force Circuit High - AutoCodes.com
C0638 Code - Left Front Normal Force Circuit High

Need More Information on the Code?

Need more information on how to fix the C0638 code? Get Access to Factory Service Manuals

Information for Specific Makes

Need Help with the Code?

Get the C0638 code diagnosed by a professional: Find a repair shop in your area

Code C0638 comments

Help us improve AutoCodes.com. Leave a comment below or tell us if the information above helps you fix the code. What are the symptoms on your vehicle for the C0638 code? Have you replaced any parts?
Any information is appreciated. Thanks