LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Nissan-Datsun >> 1998 >> Sentra Base >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - System & Component Tests >> Fuel System >> Fuel Pump System Test >> Altima
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Fuel Pump System Test: Altima

  1. Turn ignition on. With fingers, pinch fuel feed hose at fuel filter. Fuel pressure pulsation should be felt for 5 seconds after ignition is turned on. If pulsation is not felt, go to next step. If pulsation is felt, system is functioning properly.
  2. Turn ignition off. Disconnect fuel pump relay harness connector. Fuel pump relay is left-hand relay located in fuse panel above datalink connector. Turn ignition on. Measure voltage between ground and fuel pump relay harness connector terminals No. 1 (Black/Blue wire) and No. 3 (Black/White wire). Battery voltage should be present. If battery voltage is present, go to next step. If battery voltage is not present, check fuse in main fuse box. Check appropriate wire between fuse and fuel pump relay. Repair or replace as necessary.
  3. Turn ignition off. Disconnect fuel pump harness connector, located under rear seat. Check continuity between ground and fuel pump harness connector Black wire. Check continuity between fuel pump relay harness connector terminal No. 5 (Black/Yellow wire) and fuel pump harness connector Black/Yellow wire. Continuity should exist in both checks. If continuity exists in both circuits, go to next step. If continuity does not exist in either circuit, repair appropriate harness or connectors.
  4. Ensure ignition is off. Disconnect PCM harness connector. See Figure. PCM is located under center of instrument panel (connector is on passenger's side). Check continuity between PCM harness connector terminal No. 8 (Black/Pink wire) and fuel pump relay harness connector terminal No. 2 (Black/Pink wire). Continuity should exist. If continuity exists, go to next step. If continuity does not exist, repair open or short Black/Pink wire between PCM and fuel pump relay harness connectors. Repair harness and connectors as necessary.
  5. Check fuel pump relay. See RELAYS  under RELAYS & SOLENOIDS. If relay is okay, check fuel pump. See FUEL PUMP. If fuel pump relay and fuel pump are okay, check circuit harness connector terminals for pushed-out, bent, damaged or corroded terminals. Repair harness or connectors as necessary.