Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
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.
- 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.
- 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.
- 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.
CAUTION:
DO NOT use ECM ground terminals when measuring voltage.
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:
- 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.
Rather have a pro handle this?
A certified mobile mechanic comes to your home or office. They bring the tools, you stay comfortable. No tow truck, no waiting room, no surprises.
Comes to youSame-day available12-month warranty
Get a Free QuoteNo obligation. See pricing before you book.
