GDI Fuel System Priming Pump Performance
2006-2011 BMW 325i 3.0L I6 N52 🇩🇪
Description
The low-pressure electric fuel pump that primes the GDI high-pressure fuel system is not delivering adequate fuel volume or pressure to the HP pump inlet.
Symptoms
- Extended cranking time
- Hard start after sitting
- Fuel rail slow to build pressure
- Engine stalling after start
- HP pump cavitation noise
Common Causes
- Weak fuel pump motor
- Clogged fuel filter
- Fuel pump check valve leak
- Fuel tank pickup sock restricted
- Fuel pump relay intermittent
Diagnostic Steps
- Measure fuel pressure at HP pump inlet
- Test electric fuel pump current draw
- Check fuel filter restriction
- Test fuel pump check valve hold pressure
- Inspect fuel pump relay and wiring
Repair Notes
Replace low-pressure fuel pump or fuel filter. GDI systems are sensitive to feed pressure - even slight deficiency causes HP pump issues.
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
P3657 on Other Vehicles
Common Questions
What does code P3657 mean on a 2006-2011 BMW 325i?
P3657 stands for "GDI Fuel System Priming Pump Performance". The low-pressure electric fuel pump that primes the GDI high-pressure fuel system is not delivering adequate fuel volume or pressure to the HP pump inlet.
What are the symptoms of P3657 on a BMW 325i?
Common symptoms of P3657 include: Extended cranking time, Hard start after sitting, Fuel rail slow to build pressure, Engine stalling after start, HP pump cavitation noise.
What causes P3657 on a 2006-2011 BMW 325i?
Common causes of P3657 include: Weak fuel pump motor, Clogged fuel filter, Fuel pump check valve leak, Fuel tank pickup sock restricted, Fuel pump relay intermittent.