Checking Fuel Pump Operation Using Scan Tool (Land Cruiser & LX470)
- Connect scan tool to data link connector No. 3. See Fig 1-7. Turn ignition on. DO NOT start engine.
- Turn scan tool on. Select ACTIVE TEST MODE on scan tool. Using scan tool manufacturer's instructions, activate fuel pump. Remove intake manifold cover located on top of engine, above the intake manifold. Intake manifold cover must be removed for access to fuel pressure pulsation damper located at firewall end of driver's side fuel rail. See Figure-13.
- Listen for operating sound at in-tank fuel pump and check that screw at the center of fuel pressure pulsation damper moves upward due to the fuel pressure. See Figure-13.
- If fuel pump does not operate, EFI main relay, fuel pump Electronic Control Unit (ECU) or fuel pump switch may be defective, or fuel pump switch may need to be reset. For explanation of EFI main relay, fuel pump ECU and fuel pump switch operation, or resetting of fuel pump switch, see FUEL PUMP CONTROL CIRCUIT under FUEL SYSTEM. For testing of EFI main relay or fuel pump switch, see SYSTEM/COMPONENT TESTS article.
- If EFI main relay and fuel pump switch is okay, check for defective fuses or wiring circuit. See appropriate wiring diagram in WIRING DIAGRAMS article. If fuses and wiring circuit are okay, check for defective fuel pump. See CHECKING FUEL PUMP OPERATION BY APPLYING BATTERY VOLTAGE TO FUEL PUMP under FUEL SYSTEM.
NOTE:
If problem exists in the fuel pump ECU or control circuit, Diagnostic Trouble Code (DTC) P1200 may be stored in the Engine Control Module (ECM). See appropriate TESTS W/CODES
article for retrieving and servicing of any DTCs.