Easy one-page printout for the garage or repair shop
This summary uses the existing diagnostic information shown in full below.
This means that the car's computer is getting a weak signal from a sensor that helps measure how hard you're pressing the brake pedal.
The brake pressure sensor measures the pressure applied to the brakes. A 'circuit low' code indicates that the sensor is sending a signal that is lower than expected.
The C0637 code is triggered when the brake pressure sensor G circuit is reading a voltage level that is lower than the manufacturer's specified range. This could be due to a malfunctioning sensor, wiring issues, or a problem with the vehicle's computer.
• ABS warning light is on
• Brake system warning light is on
• Reduced braking performance
• Faulty brake pressure sensor
• Damaged wiring or connectors
• Malfunctioning ABS module
ABS: Anti-lock Braking System
OBD-II: On-Board Diagnostics II
• Use an OBD-II scanner to confirm the code.
• Inspect the brake pressure sensor and its wiring for damage.
• Test the sensor's voltage output with a multimeter.
• Replace the brake pressure sensor if faulty.
• Repair or replace damaged wiring or connectors.
• Reprogram or replace the ABS module if necessary.
• OBD-II scanner
• Multimeter
• Basic hand tools
$100 - $300
Moderate
• Chevrolet Silverado
• GMC Sierra
• Cadillac Escalade
• Regularly inspect brake system components.
• Ensure proper maintenance of ABS system.
• Check wiring and connectors for corrosion or damage.
Sensor Issue
• Do not ignore the ABS warning light.
• Get the vehicle checked by a professional mechanic.
Check with your vehicle manufacturer for warranty coverage on brake system components.
This code has been associated with brake pressure sensor issues in several vehicle models over the years.
Moderate – It is important to address this issue soon to ensure proper braking performance.
Driving with a malfunctioning brake system can be dangerous. Address this issue promptly to ensure vehicle safety.
• Engine running
• Vehicle stationary
The brake pressure sensor is typically located near the master cylinder or integrated into the ABS module.
Q: Can I drive with a C0637 code?
A: It's not advisable to drive with this code as it can affect braking performance.
Q: How do I reset the ABS light?
A: Fix the underlying issue first, then use an OBD-II scanner to clear the code.
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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Universal · Torque wrench
Useful when reassembly torque matters for wheel, suspension, and under-hood fasteners.
Useful when wheel, hub, or suspension hardware needs correct reassembly torque.
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Universal · Drive-on ramps
Helpful for safer access underneath the vehicle during exhaust, EVAP, and underbody inspection work.
Helpful for safer access during underbody inspection work.
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