1998 Nissan-Datsun Sentra BaseFACTORY OEM SERVICE PROCEDURE

Electrical Load: Altima

  1. Turn ignition off. Disconnect PCM harness connector. Turn ignition on. Measure voltage between ground and PCM harness connector terminal No. 55 (Blue/Red wire). See Figure. With rear window defogger on, battery voltage should exist. With rear window defogger off, zero volts should exist. If voltage is not as specified, go to step 3). If voltage is as specified, go to next step.
  2. Measure voltage between ground and PCM harness connector terminal No. 60 (Brown wire). With headlight switch on, battery voltage should exist. With headlight switch off, zero volts should exist. If voltage is not as specified, go to next step. If voltage is as specified, system is functioning normally.
  3. Turn ignition off. Check rear window defogger or headlight switch for correct operation. See REAR WINDOW DEFOGGERS article or HEADLIGHT SYSTEMS article in the ACCESSORIES/SAFETY EQUIP section. If rear window defogger or headlight switch operates normally, go to next step. If rear window defogger or headlight switch does not operate normally, repair as necessary.
  4. Check continuity between ground and PCM harness connector terminal No. 59 (Light Green/Red wire). See Figure. Turn A/C blower fan switch on. Continuity should exist with blower fan on and no continuity should exist with blower fan switch off. If continuity is as specified, go to next step. If continuity is not as specified, check and repair open or short in appropriate wire between PCM and A/C blower fan switch. Also check blower fan switch and harness connector terminals for pushed-out, bent, damaged or corroded terminals. See WIRING DIAGRAMS article.
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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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