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.
1998 Infiniti QX4FACTORY OEM SERVICE PROCEDURE
Start Signal System Test
- Turn ignition switch to START position. Measure voltage between ground and PCM harness connector terminal No. 20. See START CIRCUIT WIRE COLOR & PCM TERMINAL IDENTIFICATION table for wire color. See Figure or Figure . Battery voltage should be present in START position ONLY. Zero volts should be present in any other ignition switch position.
- If voltage is not as specified, check appropriate fuse in fuse block. If fuse is okay, repair circuit between PCM and fuse block. If voltage is as specified, check PCM terminals, harness, and connector terminals for damage or corrosion. Repair as necessary.
START CIRCUIT WIRE COLOR & PCM TERMINAL IDENTIFICATION (1)
| Application | Wire Color | ||
|---|---|---|---|
| Altima | Black/Yellow | ||
| Maxima | Brown/White | ||
| Pathfinder & QX4 | Black/Yellow | ||
| Frontier | Blue/Orange | ||
| Quest | Blue/Black | ||
| Sentra & 200SX | Black/Yellow | ||
| 240SX | Orange | ||
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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:
- • 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.
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