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Engine Controls - Basic Testing - 4-CYL: Overview Toyota Camry XV20

Testing & Diagnostics 16 illustrations ~653 words

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 (Camry, Celica, RAV4, Tacoma, Tercel, T100 & 4Runner)

  1. Remove cover (if equipped) and connect scan tool to data link connector No. 3. (Scheme 1)-8. Turn ignition on. DO NOT start engine.
  2. 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-22526-S38640081822001010300000).
  3. 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-22526-S08337873102001010300000) under FUEL SYSTEM. For testing of EFI main relay or circuit opening relay, see SYSTEM/COMPONENT TESTS article.
  4. 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.

Checking Fuel Pump Operation Using Scan Tool (Corolla)

  1. Connect scan tool to data link connector No. 3. (Scheme 1)-8. Turn ignition on. DO NOT start engine.
  2. 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 pipe at end of fuel rail. Turn ignition off. Remove scan tool. If fuel pump operates, check fuel pressure. See «FUEL PRESSURE (FUEL SYSTEM)»(ref-22526-S38640081822001010300000).
  3. 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-22526-S08337873102001010300000) under FUEL SYSTEM. For testing of EFI main relay or circuit opening relay, see SYSTEM/COMPONENT TESTS article.
  4. 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.

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Checking Fuel Pump Operation By Applying Battery Voltage To Fuel Pump

  1. On Camry, Celica, Corolla, and Tercel, remove rear seat and cover plate on floor panel for access to electrical connector at fuel pump.
  2. On RAV4, remove driver's side rear seat and cover plate on floor panel for access to electrical connector at fuel pump.
  3. On Tacoma, T100 and 4Runner, it may be necessary to lower fuel tank for access to electrical connector at fuel pump.
  4. On all models, disconnect electrical connector for 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.
  5. Connect battery voltage to specified terminals on fuel pump to activate fuel pump. (Scheme 9)-16. DO NOT apply battery voltage to fuel pump for more than 10 seconds.
  6. Listen for fuel pump operating sound. If fuel pump operates, check fuel pressure after reinstalling components. See «FUEL PRESSURE (FUEL SYSTEM)»(ref-22526-S38640081822001010300000). Disconnect battery voltage from fuel pump.
  7. 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, see CHECKING FUEL PUMP OPERATION USING SCAN TOOL under «FUEL PUMP OPERATION»(ref-22526-S07004952602001010300000) for additional testing information.

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