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 Nissan-Datsun Maxima SE, Standard, RS5F50VFACTORY OEM SERVICE PROCEDURE
ECM Power & Ground Circuits (300ZX)
- Turn ignition on. Measure voltage between ground and ECM harness connector terminal No. 16 (Orange wire). See Figure and Figure . ECM is located behind glove box. 0.8-1.0 volt should be present. Measure voltage between ground and ECM harness connector terminals No. 49 (White wire), No. 59 (White wire) and No. 109 (White wire). Battery voltage should be present. If voltages are as specified, go to step 3). If voltages are not as specified, go to next step.
- Check ECM (ECCS) relay. Relay is located in fuse box at left front of engine compartment. See RELAYS under RELAYS & SOLENOIDS. Check Green fusible link. Fusible link is located in fusible link box next to battery. Check continuity between ECM relay and battery positive terminal. Check continuity of Orange wire between ECM harness connector terminal No. 16 and ECM relay.
- Turn ignition off. Disconnect ECM harness connector. Check continuity between ground and ECM harness connector terminals No. 10 (Black wire), No. 20 (Black wire), No. 50 (Black wire), No. 60 (Black wire), No. 107 (Black wire), No. 108 (Black wire) and No. 116 (Black wire). Continuity should exist. If continuity does not exist, check chassis and engine ground connections. If ground connections are okay, repair harness or connectors.
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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