2005 Infiniti Q45FACTORY OEM SERVICE PROCEDURE

Diagnostic Procedure

  1. INSPECTION START 

    Turn ignition switch to START.

    Is any cylinder ignited? 

    Yes or No 

    1. Yes (With CONSULT-II): GO TO 2.
    2. Yes (Without CONSULT-II): GO TO  3.
    3. No: GO TO  3.
  2. CHECK OVERALL FUNCTION 

    With CONSULT-II 

    1. Start engine.
    2. Perform "POWER BALANCE" in "ACTIVE TEST" mode with CONSULT-II.
    3. Make sure that each circuit produces a momentary engine speed drop.

    OK or NG 

    1. OK: INSPECTION END 
    2. NG: GO TO 3.
    Fig 1: Display Active Test Mode
    G02369836Courtesy of NISSAN MOTOR CO., U.S.A.
  3. CHECK FUNCTION OF INJECTOR-I 
    1. Turn ignition switch OFF.
    2. Disconnect harness connector F21, F201 (bank 1) and F41, F221 (bank 2).
      Fig 2: Locating Harness Connector F21, F201 (Bank 1) And F41, F221 (Bank 2)
      G02369837Courtesy of NISSAN MOTOR CO., U.S.A.
    3. Turn ignition switch ON.
    4. Check voltage between the following;

      harness connector F21 terminal 5 and ground,

      harness connector F41 terminal 5 and ground

      1. Voltage: Battery voltage 
      Fig 3: Checking Voltage Between Harness Connector F21 And F41 Terminals
      G02369838Courtesy of NISSAN MOTOR CO., U.S.A.
    5. Turn ignition switch OFF.
    6. Disconnect ECM harness connector.
    7. Check harness continuity between the following terminals.
      HARNESS CONTINUITY CHECKING TERMINALS REFERENCE

      Cylinder Harness connector terminal ECM terminal
      1 F21terminal3 23
      3 F21 terminal2 22
      5 F21 terminal1 21
      7 F21 terminal6 44
      2 F41 terminal3 42
      4 F41 terminal2 41
      6 F41 terminal1 40
      8 F41 terminal6 63
      1. Continuity should exist. 
    8. Also check harness for short to ground and short to power.

    OK or NG 

    1. OK: GO TO  5
    2. NG: GO TO 4.
  4. DETECT MALFUNCTIONING PART 

    Check the following.

    • Harness connectors E32, F32
    • Harness connectors F21, F201
    • Harness connectors F41, F221
    • Fuse block (J/B) No. 1 connector M1
    • Fuse block (J/B) No. 2 connectors M143, E215
    • 15A fuse
    • Harness for open or short between harness connector F21 and fuse
    • Harness for open or short between harness connector F41 and fuse
    • Harness for open or short between harness connector F21 and ECM
    • Harness for open or short between harness connector F41 and ECM
      1. Repair open circuit or short to ground or short to power in harness or connectors.
  5. CHECK FUNCTION OF INJECTOR-II 

    Provide battery voltage between the following terminals, and then interrupt it. Listen to each injector operating sound.

    Fig 4: Terminals Reference Chart For Providing Battery Voltage
    G02369839Courtesy of NISSAN MOTOR CO., U.S.A.
Factory Service Tools

Use the Manual With the Right Hardware

Pair factory procedures with proven DIY tools so the instructions are easier to execute.

Disclosure: Verified tool recommendations may earn an affiliate commission at no cost to you.

When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • • You smell fuel, burning insulation, or see smoke.
  • • Brakes feel soft, pull hard to one side, or make grinding noises.
  • • The engine overheats, stalls repeatedly, or misfires under load.
  • • You are missing required tools, torque specs, or safe lifting equipment.
  • • You are not confident in the next step or safety outcome.