GDI Fuel Rail Pressure Oscillation Detected
2012-2016 Subaru Impreza 2.0L H4
Description
The fuel rail pressure in the GDI system is oscillating beyond normal limits, indicating a control instability or mechanical issue in the high-pressure fuel system.
Symptoms
- Check Engine Light
- Engine vibration at idle
- Fuel injector noise louder than normal
- Idle quality degradation
- Possible misfire symptoms
- Fuel smell intermittent
Common Causes
- HP fuel pump volume control valve hunting
- Fuel rail pressure sensor noise
- Pressure damper failure in fuel rail
- Fuel injector leak causing pressure drops
- HP pump cam follower uneven wear
Diagnostic Steps
- Monitor fuel rail pressure waveform with fast data rate
- Check HP pump volume control solenoid
- Inspect pressure damper in fuel rail
- Test fuel injectors for leak-back
- Inspect HP pump cam follower for uneven wear
Repair Notes
Replace pressure damper if failed. Service volume control solenoid. Replace cam follower if showing uneven wear.
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
P3658 on Other Vehicles
Common Questions
What does code P3658 mean on a 2012-2016 Subaru Impreza?
P3658 stands for "GDI Fuel Rail Pressure Oscillation Detected". The fuel rail pressure in the GDI system is oscillating beyond normal limits, indicating a control instability or mechanical issue in the high-pressure fuel system.
What are the symptoms of P3658 on a Subaru Impreza?
Common symptoms of P3658 include: Check Engine Light, Engine vibration at idle, Fuel injector noise louder than normal, Idle quality degradation, Possible misfire symptoms, Fuel smell intermittent.
What causes P3658 on a 2012-2016 Subaru Impreza?
Common causes of P3658 include: HP fuel pump volume control valve hunting, Fuel rail pressure sensor noise, Pressure damper failure in fuel rail, Fuel injector leak causing pressure drops, HP pump cam follower uneven wear.