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.
1993 Infiniti Q45 BaseFACTORY OEM SERVICE PROCEDURE
Ignition Coil Power Source
- Turn ignition off. Disconnect ignition coil relay harness connector. Turn ignition on. Connect negative voltmeter lead to ground. On J30, connect positive lead to one harness Yellow/Black wire and then to the other Yellow/Black wire. On Q45, connect positive lead to harness Black/White wire and then to harness White/Black wire. On all models, battery voltage should be present on both terminals.
- On J30, if battery voltage is not present, check harness continuity between ECCS relay and EFI harness connector (Yellow/Black wire) and 7.5 amp fuse in fuse box. On Q45, if battery voltage is not present, check main harness connector, 30-amp fusible link in relay block, harness continuity between ignition coil relay and ignition switch, and harness continuity between ignition coil relay and battery. Repair or replace as necessary.
Factory Service Tools
Use the Manual With the Right Hardware
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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.