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HITACHI

16625AA040

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SolenoidSubaru Direct Injection Turbo (DIT) 200-bar Fuel SystemEuro 3306

HITACHI 16625AA040 High Pressure Fuel Pump Subaru WRX Forester XT Ascent 2.0T 2.4T FA20F FA24F

Reference data for Bosch 16625AA040 common rail injector · OEM 16625AA000, HUP0044 · Application Subaru / Toyota 2.0L & 2.4L Boxer DIT / D-4S (FA20D / FA20F / FA24D / FA24F)
Engine Platform:Subaru / Toyota 2.0L & 2.4L Boxer DIT / D-4S (FA20D / FA20F / FA24D / FA24F) →
OE REFERENCE16625AA000, HUP0044
CONTROL VALVEIntegrated High-Speed Flow Control Spill Valve
NOZZLE-
RAIL PRESSURE200 bar
EMISSIONTier 3 Bin 30 / Euro 6d / LEV III
WARRANTY12 Months
01

Compatible Injectors

OEM Ref
02

Vehicle & Engine Fitment

VehicleEngineYears
Subaru WRX VASubaru / Toyota 2.0L & 2.4L Boxer DIT / D-4S (FA20D / FA20F / FA24D / FA24F)2015-2021
Subaru Forester XT SJSubaru / Toyota 2.0L & 2.4L Boxer DIT / D-4S (FA20D / FA20F / FA24D / FA24F)2014-2018
Subaru Ascent WNSubaru / Toyota 2.0L & 2.4L Boxer DIT / D-4S (FA20D / FA20F / FA24D / FA24F)2019-2024
03

Technical Specifications

SpecificationValue
System TypeHitachi Cam-Driven Single-Plunger Mechanical High-Pressure Fuel Pump
Operating PressureCore Spec
Drive ConfigurationHorizontal-opposed boxer exhaust camshaft drive lobe with roller tappet
Flange Mounting Bolt Torque12 N·m (flanged retaining screws torqued alternately)
High Pressure Line Torque27 N·m (rigid flared delivery pipe fitting)
Flow Regulator Valve Resistance8.8 - 10.8 Ω at 20°C (proportional metering solenoid)
Common Fault CodesP0087 (Fuel Rail Pressure Low), P0088 (Rail Pressure High), P0090 (Fuel Pressure Regulator Control)
Workshop PrecautionLubricate internal drive plunger and roller bucket contact surface with clean motor oil
04

Installation Tips

  1. [
  2. {
  3. "step": 1,
  4. "title": "Relieve Direct Injection Pressure & Disconnect Battery",
  5. "instruction": "Depressurize fuel line via scan tool command or fuel pump relay removal. Disconnect negative battery ground."
  6. },
  7. {
  8. "step": 2,
  9. "title": "Remove Intercooler Piping & Foam Sound Damper",
  10. "instruction": "Remove upper charge air piping on passenger side of engine bay. Unclip protective foam sound insulation around HPFP."
  11. },
  12. {
  13. "step": 3,
  14. "title": "Disconnect Fuel Unions & Mounting Flange Fasteners",
  15. "instruction": "Unplug electrical harness from flow control solenoid. Disconnect high-pressure pipe (27 N·m). Back out two flange bolts evenly to release spring tension."
  16. },
  17. {
  18. "step": 4,
  19. "title": "Reinstall Replacement Pump, Torque Bolts & Test Pressure",
  20. "instruction": "Fit new lubricated O-ring seal. Torque mounting flange bolts alternately to 12 N·m. Tighten delivery line to 27 N·m. Crank engine and verify fuel rail pressure."
  21. }
  22. ]
05

Diagnostic Trouble Codes & Fault Protocols

Common diagnostic trouble codes (DTCs) triggered when this common rail injector experiences wear, circuit faults, or calibration drift:

P0087Critical

Fuel Rail / System Pressure Too Low

Excessive internal backleak from worn control valve seats drops common rail pressure below target under engine load.

P0087 Guide →🧪 Backleak Calculator
P0201 - P0208High

Injector Circuit Malfunction / Open Circuit

Solenoid coil resistance drift (0.2-0.5 Ω) or piezo stack degradation triggers driver stage shutdown on affected cylinders.

P0201 Circuit Guide →
P0300 / P0301+High

Cylinder Misfire & Balancing Deviation

Carbon-clogged nozzle spray holes or missing IMA calibration causes uneven cylinder contribution. Recode ECM and verify washer seating.

P0300 Misfire Protocol →💻 IMA Coding Tool📐 Washer Thickness
P0088High

Fuel Rail / System Pressure Too High

Spill line backpressure or stuck metering valve prevents rail depressurization, creating overpressure risks under load.

P0088 Guide →📊 Rail Pressure Converter
Browse all 61 Diesel Diagnostic Trouble Codes in our Workshop Hub ->
WORKSHOP PROTOCOLS

Technical Diagnostic & Service Protocols

Authoritative field procedures, diagnostic testing thresholds, and service SOPs for this assembly.

COMMON RAIL WORKSHOP DIAGNOSTICS

Common Rail High-Pressure Pump Diagnostics Guide

Diagnose common rail high-pressure pump failure: suction vacuum, CP4 roller glitter, plunger wear, air ingress & P0087 hard start. Workshop bench testing.

Read Technical Protocol
COMMON RAIL WORKSHOP DIAGNOSTICS

Fuel Metering Valve (IMV/SCV) Diagnostics Guide

Diagnostic guide for common rail fuel metering valves (IMV/SCV/FCA/MPROP). Normally open vs closed, coil resistance, PWM duty cycle & P0088 / P0089 test.

Read Technical Protocol
OBD-II DIAGNOSTIC PROTOCOL

P0087 Low Rail Pressure Diagnosis Guide

Step-by-step workshop diagnostic protocol for OBD-II DTC P0087 (Fuel Rail Pressure Too Low). 5-stage troubleshooting tree: backleak testing, SCV valve, PRV valve, and high-pressure pump.

Read Technical Protocol
COMMON RAIL WORKSHOP DIAGNOSTICS

Rail Pressure Relief Valve Diagnostics Guide

Common rail pressure relief valve (PRV) testing guide. Diagnose hot start stalls, P0087 rail pressure loss, return line leakage & single vs 2-stage valves.

Read Technical Protocol