Start-Stop Brake Vacuum Pump Performance
2014-2021 Mazda Mazda6 2.5L I4
Description
The electric brake vacuum pump that maintains brake boost during engine-off periods in start-stop systems is not providing adequate vacuum.
Symptoms
- Start-stop disabled
- Firm brake pedal during engine stop
- Brake assist warning
- Start-stop inhibited due to brake system
- Hard pedal after one or two stops
Common Causes
- Electric vacuum pump motor weak
- Check valve in vacuum line leaking
- Vacuum line crack or disconnect
- Pump control module fault
- Brake booster diaphragm leak
Diagnostic Steps
- Monitor brake vacuum level during engine-off events
- Test electric vacuum pump operation
- Check vacuum lines and check valves
- Measure vacuum decay rate with engine off
- Test brake booster for leaks
Repair Notes
Replace electric vacuum pump or check valve. Repair vacuum line leaks. Ensure brake boost is adequate during engine-off periods.
Related Codes
Other Powertrain Codes
- P0001Fuel Volume Regulator Control Circuit/Open
- P0002Fuel Volume Regulator Control Circuit Range/Performance
- P0003Fuel Volume Regulator Control Circuit Low
- P0004Fuel Volume Regulator Control Circuit High
- P0010Intake Camshaft Position Actuator Circuit/Open Bank 1
- P0011Intake Camshaft Position Timing Over-Advanced Bank 1
- P0012Intake Camshaft Position Timing Over-Retarded Bank 1
- P0013Exhaust Camshaft Position Actuator Circuit/Open Bank 1
- P0014Exhaust Camshaft Position Timing Over-Advanced Bank 1
- P0015Exhaust Camshaft Position Timing Over-Retarded Bank 1
P3604 on Other Vehicles
Common Questions
What does code P3604 mean on a 2014-2021 Mazda Mazda6?
P3604 stands for "Start-Stop Brake Vacuum Pump Performance". The electric brake vacuum pump that maintains brake boost during engine-off periods in start-stop systems is not providing adequate vacuum.
What are the symptoms of P3604 on a Mazda Mazda6?
Common symptoms of P3604 include: Start-stop disabled, Firm brake pedal during engine stop, Brake assist warning, Start-stop inhibited due to brake system, Hard pedal after one or two stops.
What causes P3604 on a 2014-2021 Mazda Mazda6?
Common causes of P3604 include: Electric vacuum pump motor weak, Check valve in vacuum line leaking, Vacuum line crack or disconnect, Pump control module fault, Brake booster diaphragm leak.