Quick Answer
P0579 means: P0579 indicates a high voltage fault in the brake switch A circuit.
Can I drive with P0579? Immediate attention is recommended due to potential safety risks.
Common Questions
What does P0579 mean and how does it affect my car?
The P0579 code indicates a problem with the brake switch, which is essential for signaling when the brakes are applied. This affects systems like the cruise control and can even prevent the car from starting. If this code appears, it's crucial to address it quickly to ensure safe driving.
What are the most common causes of P0579 and how much does it cost to fix?
Common causes include a faulty brake switch, damaged wiring, or corrosion at the connectors. Repair costs can range from $50 for a simple switch replacement to over $600 for ECM issues. It's important to diagnose accurately to avoid unnecessary repairs.
Can I drive my car with P0579 or should I stop immediately?
Driving with a P0579 code is risky, especially if the brake system behaves erratically. It's advisable to have the issue diagnosed and repaired as soon as possible to avoid potential accidents.
How can I diagnose P0579 myself using GeekOBD APP?
Using the GeekOBD APP, you can scan for trouble codes, view freeze frame data, and monitor the brake switch's signal status. Follow the app's prompts to perform tests and check for voltage at the brake switch connector to aid in diagnosis.
What vehicles are most commonly affected by P0579?
Vehicles like the 2007-2015 Toyota Camry, 2010-2015 Honda Accord, and 2011-2015 Ford Fiesta frequently experience the P0579 code. Always check for recalls or technical service bulletins that may address known issues.
How can I prevent P0579 from happening again?
Regular maintenance, including electrical system checks and ensuring that connections and switches are free from corrosion, can help prevent P0579. Keeping your vehicle's wiring in good condition is key to long-term reliability.
What is P0579?
The diagnostic trouble code (DTC) P0579 indicates a fault in the brake switch 'A' circuit, where the signal voltage is higher than expected. This code typically pertains to the brake pedal position switch, which plays a crucial role in vehicle safety and performance. When you press the brake pedal, this switch sends a signal to the engine control module (ECM) indicating that the brakes are engaged. A malfunction can lead to various driving issues, such as the cruise control not disengaging or the brake lights remaining on. In some cases, this can also affect the vehicle's ability to start, as the system may assume that the brakes are not being applied. Common symptoms include the check engine light illuminating, erratic brake light behavior, and even potential safety risks if the brakes fail to operate correctly. If left unresolved, this could lead to increased wear on other components, as well as driving hazards due to improper brake function. Therefore, addressing a P0579 code promptly is essential for maintaining vehicle safety.
System: P - Powertrain (Engine, Transmission, Emissions)
Symptoms
Common symptoms when P0579 is present:
- Check engine light stays on constantly, indicating a persistent fault that needs attention.
- Cruise control system fails to disengage when the brake pedal is pressed, posing a risk during driving.
- Brake lights remain illuminated even when the vehicle is not braking, which can confuse other drivers.
- Vehicle may experience difficulty starting if the system fails to recognize the brake pedal is applied.
- Unusual behavior of other electrical components, as the brake switch may affect systems like traction control.
Possible Causes
Most common causes of P0579 (ordered by frequency):
- Most common cause: Faulty brake switch (60% likelihood). This can be due to wear and tear or electrical failure.
- Second most common cause: Wiring issues such as frayed wires or bad connectors that disrupt the signal to the ECM.
- Third cause: Corrosion at the brake switch connector, which can impede electrical flow and lead to malfunction.
- Less common but serious cause: A malfunctioning ECM that incorrectly interprets inputs from the brake switch.
- Rare but possible cause: Water intrusion into the switch or connectors, which can cause short circuits or corrosion.
P0579 Repair Costs
Cost Breakdown by Repair Type
Brake Switch Replacement
Replacing the faulty brake switch is often the first step in resolving P0579.
- Total: $50 - $150
- Success rate: 85%
Wiring Repair
Repairing or replacing damaged wiring and connectors as necessary.
- Total: $30 - $100
- Success rate: 75%
ECM Reprogramming
In cases where the ECM is faulty, reprogramming or replacement may be required.
- Total: $200 - $600
- Success rate: 65%
Money-Saving Tips for P0579
- Start with the most common and least expensive repairs first
- Use GeekOBD APP to confirm diagnosis before replacing expensive parts
- Consider preventive maintenance to avoid future occurrences
- Compare prices for OEM vs aftermarket parts based on your needs
- Address the issue promptly to prevent more expensive secondary damage
Diagnostic Steps
Professional P0579 Diagnosis Process
Follow these systematic steps to accurately diagnose P0579. Each step builds on the previous one to ensure accurate diagnosis.
Step 1: Step 1: Initial visual inspection - Check for obvious signs like damaged wiring, loose connections, or corrosion (5-10 minutes)
Step 1: Initial visual inspection - Check for obvious signs like damaged wiring, loose connections, or corrosion (5-10 minutes).
Step 2: Step 2: OBD2 scan with GeekOBD APP - Retrieve all codes and freeze frame data to understand the fault context (10-15 minutes)
Step 2: OBD2 scan with GeekOBD APP - Retrieve all codes and freeze frame data to understand the fault context (10-15 minutes).
Step 3: Step 3: Component testing - Use a multimeter to test the brake switch's continuity and operation (20-30 minutes)
Step 3: Component testing - Use a multimeter to test the brake switch's continuity and operation (20-30 minutes).
Step 4: Step 4: System function test - Verify proper operation of the brake switch after repairs and clear codes (10-15 minutes)
Step 4: System function test - Verify proper operation of the brake switch after repairs and clear codes (10-15 minutes).
Step 5: Step 5: Road test verification - Drive the vehicle under various conditions to confirm the repair success (15-20 minutes)
Step 5: Road test verification - Drive the vehicle under various conditions to confirm the repair success (15-20 minutes).
Important Notes
- Always verify the repair with GeekOBD APP after completing diagnostic steps
- Clear codes and test drive to ensure the problem is resolved
- Address underlying causes to prevent code recurrence
Real Repair Case Studies
Case Study 1: Brake Switch Replacement on 2012 Toyota Camry
Vehicle: 2012 Toyota Camry, 85,000 miles
Problem: Customer reported check engine light and cruise control not disengaging.
Diagnosis: Through OBD2 scanning and visual inspection, the faulty brake switch was identified.
Solution: Replaced the brake switch and cleared the codes.
Cost: $120 (including parts and labor)
Result: Customer reported successful operation of the cruise control and no further check engine light.
Case Study 2: Wiring Repair on 2014 Honda Accord
Vehicle: 2014 Honda Accord, 70,000 miles
Problem: Brake lights remained on continuously, and check engine light was illuminated.
Diagnosis: Identified damaged wiring leading to the brake switch, affecting the circuit.
Solution: Repaired wiring and reconnected the brake switch.
Cost: $80 (for wiring repairs)
Result: Brake lights functioned normally, and the check engine light was no longer illuminated.