FUEL PUMP OPERATION
Note. Electric fuel pump operation may be checked by using scan tool or by applying battery voltage to electric fuel pump. Electric fuel pump is located in the fuel tank.
Checking Fuel Pump Operation Using Scan Tool (Avalon, Camry, Sienna, Tacoma, T100 & 4Runner)
- Remove cover (if equipped) and connect scan tool to data link connector No. 3. (Scheme 38)-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. Listen for fuel pump operating sound and feel for fuel pressure in fuel inlet line at fuel filter. Turn ignition off. Remove scan tool. If fuel pump operates, check fuel pressure. See «FUEL PRESSURE (FUEL SYSTEM)»(ref-22528-S37478176462001010300000).
- If fuel pump does not operate, EFI main relay or circuit opening relay may be defective. For relay application and explanation of relay operation, see «FUEL PUMP CONTROL CIRCUIT»(ref-22528-S01427151262001010300000) under FUEL SYSTEM. For testing of EFI main relay or circuit opening relay, see SYSTEM/COMPONENT TESTS article.
- If relays are okay, check for defective fuses, fusible links or wiring circuit. See appropriate wiring diagram in WIRING DIAGRAMS article. If fuses, fusible links 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. If fuel pump operates properly, Engine Control Module (ECM) may be defective.
Checking Fuel Pump Operation Using Scan Tool (Land Cruiser & LX470)
- Connect scan tool to data link connector No. 3. (Scheme 38)-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. (Scheme 45)-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. (Scheme 45)-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»(ref-22528-S01427151262001010300000) 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.
Scheme 38
Scheme 39
Scheme 40
Scheme 41
Scheme 42
Scheme 43
Scheme 44
Checking Fuel Pump Operation By Applying Battery Voltage To Fuel Pump
- On Avalon and Camry, remove rear seat and cover plate on floor panel for access to fuel pump electrical connector.
- On Land Cruiser & LX470, remove second seats, scuff plate, step plate, floor mats and cover plate on floor panel for access to fuel pump electrical connector.
- On Sienna, manufacturer recommends removing fuel tank for access to fuel pump.
- On Tacoma, T100 and 4Runner, it may be necessary to lower fuel tank for access to fuel pump electrical connector.
- On all models, disconnect fuel pump electrical connector. Electrical connector for fuel pump is located on top of fuel tank, near fuel pump. CAUTION: When applying battery voltage to fuel pump, DO NOT apply battery voltage for more than 10 seconds or fuel pump may be damaged.
- Connect battery voltage to specified terminals on fuel pump to activate fuel pump. (Scheme 51) DO NOT apply battery voltage to fuel pump for more than 10 seconds.
- Listen for fuel pump operating sound. If fuel pump operates, check fuel pressure after reinstalling components. See «FUEL PRESSURE (FUEL SYSTEM)»(ref-22528-S37478176462001010300000). Disconnect battery voltage from fuel pump.
- If fuel pump fails to operate, replace fuel pump and/or lead wire to the fuel pump (if equipped). See REMOVE/INSTALL/OVERHAUL article. If fuel pump will not operate while trying to start engine, EFI main relay, circuit opening relay, fuses, fusible links, wiring circuit or Engine Control Module (ECM) may be defective. See appropriate CHECKING FUEL PUMP OPERATION USING SCAN TOOL under «FUEL PUMP OPERATION»(ref-22528-S37901857482001010300000) for additional testing information.
