Easy one-page printout for the garage or repair shop
This summary uses the existing diagnostic information shown in full below.
This code means that the car's computer thinks there's a problem with a sensor that checks how hard you're pressing the brake pedal.
The code C0638 indicates an issue with the brake pressure sensor, which monitors the pressure applied to the brake system.
The C0638 code is triggered when the brake pressure sensor 'G' sends a signal to the vehicle's control module that is outside the expected range or performance parameters. This sensor is crucial for ensuring the brake system functions correctly by providing real-time data on brake pressure.
• ABS warning light on
• Brakes may feel spongy
• Reduced braking performance
• Faulty brake pressure sensor
• Damaged wiring or connectors
• Malfunctioning brake control module
OBD-II: On-Board Diagnostics, a standardized system for vehicle diagnostics.
ABS: Anti-lock Braking System, a safety system that prevents wheels from locking up during braking.
• Use an OBD-II scanner to confirm the code.
• Inspect the brake pressure sensor and its wiring.
• Test the brake pressure sensor for proper operation.
• Replace the faulty brake pressure sensor.
• Repair or replace damaged wiring or connectors.
• Reprogram or replace the brake control module if necessary.
• OBD-II scanner
• Multimeter
• Wrench set
$150 - $400
Moderate
• Chevrolet Silverado
• GMC Sierra
• Cadillac Escalade
• Regularly inspect brake system components.
• Ensure brake fluid levels are maintained.
• Check wiring and connectors for damage.
Sensor Issue
• Have your brakes inspected by a professional.
• Do not ignore the ABS warning light.
• Regular maintenance can prevent sensor issues.
Check with your vehicle manufacturer for warranty coverage on brake system components.
This code has been associated with vehicles using advanced brake systems that rely on sensor data for optimal performance.
High – Braking performance can be compromised, which is a safety concern.
Driving with a faulty brake system can be dangerous and may violate vehicle safety regulations.
• Vehicle must be stationary.
• Engine should be running to test sensor output.
The brake pressure sensor is typically located near the master cylinder or integrated into the ABS module.
Q: Can I drive with a C0638 code?
A: It's not recommended to drive with this code active, as it may affect your braking performance.
Q: How do I reset the C0638 code?
A: After repairs, use an OBD-II scanner to clear the code. If the issue is fixed, it should not return.
Pro · Four-system diagnostics
A handheld scanner aimed at engine, transmission, ABS, and airbag diagnostic work.
Chassis and ABS faults usually need a scanner that can read brake-system data directly.
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