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Home >> Mazda >> 2003 >> Tribute DX, FWD >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - Self-Diagnostics >> System Tests >> Fuel Pump Inspection
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Fuel Pump Inspection

  1. Check Fuel Pump For Operation -  Verify battery is fully charged. Verify fuel tank unit 4-pin harness connector is securely connected. Turn ignition on, engine off. Connect scan tool to DLC. Select PCM, ACTIVE COMMAND MODE, OUTPUT TEST MODE and fuel pump PID. Press MODE to change to ALL ON MODE. Press START to run fuel pump and listen for fuel pump operation. Press STOP. If fuel pump operation was not heard, go to next step. If fuel pump operation was heard, go to FUEL DELIVERY SYSTEM  testing for more trouble shooting procedures.
  2. Check Fuel Pump For Continuity -  Turn ignition off. Disconnect fuel tank unit 4-pin harness connector. Check for continuity between fuel tank unit 4-pin connector power terminal (Pink/Black wire) and ground terminal (Black wire). See appropriate WIRING DIAGRAM under ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS. If continuity present is present, go to next step. If continuity is not present, replace fuel pump module.
  3. Check Voltage At Fuel Pump (Vehicle Harness Connected) -  Turn ignition on, engine off. Select DIAGNOSTIC DATA LINK, PCM, ACTIVE COMMAND MODE, OUTPUT TEST MODE and fuel pump PID. Press MODE to change to ALL ON MODE. Press START to run fuel pump and measure voltage at fuel tank unit 4-pin connector power terminal (Pink/Black wire). Press STOP. If voltage reading is more than 10.5 volts, go to next step. If voltage reading is 10.5 volts or less, check fuel pump relay or Inertia Fuel Shut-off (IFS) switch.
  4. Check Fuel Pump Ground Circuit -  Ensure fuel tank unit 4-pin harness connector. Measure resistance between fuel tank unit 4-pin connector ground terminal (Black wire) and chassis ground. If resistance is less than one ohm, ground circuit is okay. Recheck fuel pump. If resistance reading is one ohm or more, repair open circuit in Black wire between fuel tank unit 4-pin harness connector and chassis ground.
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