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Code C0581

Symptoms

• Increased effort needed to brake

• Brake warning light on the dashboard

• Unusual noises when braking

Common Causes

• Faulty brake booster motor

• Short circuit in the wiring

• Malfunctioning control module

Glossary

Brake Booster: A device that helps reduce the effort needed to apply the vehicle's brakes.

PCM: Powertrain Control Module, the computer that controls the engine and transmission.

Related Codes

• C0580

• C0582

Laymans terms

This code means there's a problem with the electric motor that helps you brake. It's like when a toy's battery is too strong and makes it act funny.

Explanation

The code indicates that the voltage in the circuit controlling the brake booster motor is higher than expected.

Technical description

OBD-II code C0581 is triggered when the powertrain control module (PCM) detects an unusually high voltage condition in the U-V-W phase circuit of the brake booster motor. This motor is part of the system that assists in applying the brakes, making it easier to stop the vehicle. A high voltage condition may indicate a short circuit or a fault in the motor or its control circuitry.

Diagnosis steps

• Use a diagnostic scanner to confirm the code.

• Inspect the wiring and connectors for damage.

• Test the brake booster motor for proper operation.

Repair procedures

• Repair or replace damaged wiring.

• Replace the brake booster motor if faulty.

• Replace or reprogram the control module if necessary.

Tools required

• Diagnostic scanner

• Multimeter

• Wrench set

Estimated repair cost

$150 - $500

Difficulty level

Moderate

Commonly affected vehicles

• Chevrolet Silverado

• GMC Sierra

• Cadillac Escalade

Preventive measures

• Regularly inspect brake system components.

• Ensure all electrical connections are secure.

• Perform routine maintenance checks.

Error code type

Brake System Issue

User experience recommendations

• Do not ignore the brake warning light.

• Have the vehicle inspected by a professional.

• Avoid driving the vehicle until the issue is resolved.

Warranty information

Repairs may be covered under the vehicle's powertrain or brake system warranty.

Historical data

This code has been associated with electrical issues in brake booster systems, particularly in vehicles with electric brake assist.

Urgency level

High – Brake system issues can affect vehicle safety and should be addressed immediately.

Legal and safety notice

Driving with a malfunctioning brake system can be dangerous. Ensure repairs are performed by a qualified technician.

Testing conditions

• Vehicle parked on a level surface

• Engine running

Component location

The brake booster motor is typically located near the brake pedal assembly or integrated into the brake system under the hood.

FAQs

Q: Can I drive with code C0581?
A: It's not safe to drive with this code as it affects the braking system. Have it checked immediately.

Q: How do I reset the C0581 code?
A: After repairs, use an OBD-II scanner to clear the code. If the issue persists, the code will reappear.

Last updated: Jun 8, 2026 • Source: internal database
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