P3651high severityPowertrain
GDI Fuel Rail Pressure Too Low During Cranking
on 2011 Land Rover Discovery 5.0L V8 · AWD
What this code means
The fuel rail pressure in the GDI system does not reach the minimum required pressure during engine cranking.
Symptoms
- Extended cranking time
- No start condition
- Rough start then smooths out
- Fuel rail pressure reads low on scan tool
- May start after multiple attempts
Common causes
- Worn high-pressure fuel pump
- Fuel injector leaking back
- Rail pressure sensor error
- Low-pressure supply pump weak
- Fuel check valve leaking
Diagnostic steps
- Monitor rail pressure during cranking
- Check low-pressure fuel supply
- Test fuel injector leak-back
- Inspect high-pressure pump cam follower
- Measure cranking RPM
Repair notes
{"Replace high-pressure fuel pump. Test fuel injectors for leak-back. Ensure low-pressure supply exceeds minimum feed pressure."}
Other Powertrain codes on this vehicle
P0001
Fuel Volume Regulator Control Circuit/Open
P0002
Fuel Volume Regulator Control Circuit Range/Performance
P0003
Fuel Volume Regulator Control Circuit Low
P0004
Fuel Volume Regulator Control Circuit High
P0010
Intake Camshaft Position Actuator Circuit/Open Bank 1
P0011
Intake Camshaft Position Timing Over-Advanced Bank 1
P0012
Intake Camshaft Position Timing Over-Retarded Bank 1
P0013
Exhaust Camshaft Position Actuator Circuit/Open Bank 1
P0014
Exhaust Camshaft Position Timing Over-Advanced Bank 1
P0015
Exhaust Camshaft Position Timing Over-Retarded Bank 1