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 Sentra SE-R, AutomaticFACTORY OEM SERVICE PROCEDURE
Fuel Injector System Test (Quest Non-California)
- With engine running, measure voltage between ground and ECM harness connector terminals No. 101 (Green/Orange wire), No. 103 (Green/Red wire), No. 105 (Yellow/Green wire), No. 110 (Green wire), No. 112 (Yellow/Purple wire) and No. 114 (Gray/Blue wire). ECM is located behind glove box. See Figure and Figure . Battery voltage should be present. If battery voltage is not present, go to next step. If battery voltage is present, system is functioning properly.
- Turn ignition off. Disconnect each injector harness connector. Disconnect ECM harness connector. Measure voltage between ground and each injector harness connector Yellow wire. Measure voltage between ground and ECM harness connector terminal No. 46 (Yellow wire). Battery voltage should be present. If battery voltage is present, go to next step. If battery voltage is not present, check 25-amp fusible link located in fusible link box next to battery. If fusible is okay, repair or replace harness or connectors.
- Check continuity between ECM harness connector terminals No. 101 (Green/Orange wire), No. 103 (Green/Red wire), No. 105 (Yellow/Green wire), No. 110 (Green wire), No. 112 (Yellow/Purple wire) and No. 114 (Gray/Blue wire) and corresponding injector harness connector wire color. Continuity should exist. If continuity exists, check injector. See FUEL INJECTOR TEST. If injector is okay, check ECM pin terminals and ECM harness connector terminals for damage or corrosion. Repair or replace as necessary. If continuity does not exist, repair or replace 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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