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2014 LINCOLN MKX

3.5L V6AWDAUTOMATICgas
1 active safety recall on this vehicle — view recalls
Repairs0Labor515Torque3889Fluid9DTC952Battery0Maintenance0Recalls1
P3651high severityPowertrain

GDI Fuel Rail Pressure Too Low During Cranking

on 2014 Lincoln MKX 3.5L V6 · 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

  1. Monitor rail pressure during cranking
  2. Check low-pressure fuel supply
  3. Test fuel injector leak-back
  4. Inspect high-pressure pump cam follower
  5. 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

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