2003 Infiniti Q45FACTORY OEM SERVICE PROCEDURE

DTC Confirmation Test (Using Generic Scan Tool)

NOTE: Use the following test to check overall function of fuel level sensor circuit. During this test, 1st trip DTC may not be confirmed.
  1. To check overall function of fuel level sensor circuit, release fuel system pressure. See FUEL SYSTEM in BASIC DIAGNOSTIC PROCEDURES article. Remove fuel feed hose from fuel level sensor unit located under trunk liner.
  2. CAUTION: DO NOT use ECM ground terminals when measuring voltage.
  3. Connect a fuel hose to fuel level sensor unit. Place other end of hose into a suitable fuel container. Turn ignition off. Set voltmeter probes between ground and fuel level sensor signal circuit at ECM terminal No. 119 (Red/Blue wire) by backprobing. See Figure and Figure . Turn ignition on and monitor voltmeter.
  4. Using suitable equipment, drain 7.93 Gals. (30.0 L) of fuel from tank. Refill tank with drained fuel. Voltage should change more than .03 volt during draining and refilling. If voltage is not as specified, go to DIAGNOSTIC PROCEDUREΒ  . If voltage is as specified, system is okay at this time.
Factory Service Tools

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When to See a Mechanic

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

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

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