1993 Nissan-Datsun Sentra SE-R, AutomaticFACTORY OEM SERVICE PROCEDURE

Fuel Injector System Test (Altima)

  1. With engine running, measure voltage between ground and ECM harness connector terminals No. 101 (Brown wire), No. 103 (Brown/Yellow wire), No. 110 (Brown/White wire), and No. 112 (Brown wire). ECM is located under center of instrument panel. 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.
  2. Turn ignition off. Disconnect each injector harness connector. Measure voltage between ground and each injector harness connector White wire. Battery voltage should be present. If battery voltage is present, go to next step. If battery voltage is not present, check 75-amp fusible link and 10-amp fuse located in engine compartment fuse box. If 75-amp fusible link and 10-amp fuse are okay, repair or replace harness or connectors.
  3. Ensure ignition is off. Disconnect ECM harness connector. Measure voltage between ground and ECM harness connector terminal No. 109 (White wire). Battery voltage should be present. If battery voltage is present, go to next step. If battery voltage is not present, check 25-amp fuse, located in fuse box in engine compartment. If 25-amp fuse is okay, repair or replace harness or connectors.
  4. Check continuity between ECM harness connector terminals No. 101 (Brown wire), No. 103 (Brown/Yellow wire), No. 110 (Brown/White wire), and No. 112 (Brown 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.
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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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