Toyota Avalon (XX50): Fuel System

On-vehicle Inspection

ON-VEHICLE INSPECTION

PROCEDURE

1. CHECK FUEL PUMP OPERATION AND INSPECT FOR FUEL LEAK

(a) Check fuel pump operation.

(1) Connect the Techstream to the DLC3.

(2) Turn the engine switch on (IG).

NOTICE:

Do not start the engine.

(3) Turn the Techstream on.

(4) Enter the following menus: Powertrain / Engine / Active Test / Activate the Circuit Relay.

(5) Check for pressure in the fuel tube sub-assembly from the fuel line. Check that sounds of fuel flowing from the fuel tank assembly can be heard. If no sounds can be heard, check the relay, fuel pump, ECM and wiring connectors.

(b) Inspect for fuel leaks.

(1) Check that there are no fuel leaks from the fuel system after doing any maintenance or repairs. If there is a fuel leak, repair or replace parts as necessary.

(c) Turn the engine switch off.

(d) Disconnect the Techstream from the DLC3.

2. CHECK FUEL PRESSURE

(a) Discharge fuel system pressure.

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(b) Measure the battery voltage.

Standard Voltage:

11 to 14 V

(c) Disconnect the cable from the negative (-) battery terminal.

NOTICE:

When disconnecting the cable, some systems need to be initialized after the cable is reconnected.

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(d) Disengage the 2 claws to remove the No. 2 fuel pipe clamp.

(e) Remove the No. 1 fuel pipe clamp from the fuel tube connector.

(f) Disconnect the No. 2 fuel tube sub-assembly (for Direct Injection). (1) Disconnect the No. 2 fuel tube sub-assembly from the fuel pipe. Click here

(g) Disconnect the fuel tube sub-assembly (for Port Injection). (1) Disconnect the fuel tube sub-assembly from the fuel pipe. Click here

(h) Install SST (EFI fuel pressure gauge) as shown in the illustration. SST: 09268-45101 09268-41250 09268-41260 09268-41280 09268-41500 09268-41700 95336-08070

*1 Fuel Tube Sub-assembly (Vehicle Side) *a SST (Hose Band) *b SST (T-joint) *c SST (Gauge) *d SST (Hose Joint) *e SST (Hose) *f SST (Fuel Tube Connector) *g Fuel Pipe (Vehicle Side)

(i) Wipe up any spilled fuel.

(j) Connect the cable to the negative (-) battery terminal.

NOTICE:

When disconnecting the cable, some systems need to be initialized after the cable is reconnected.

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(k) Connect the Techstream to the DLC3.

(l) Turn the engine switch on (IG).

NOTICE:

Do not start the engine.

(m) Turn the Techstream on.

(n) Enter the following menus: Powertrain / Engine / Active Test / Activate the Circuit Relay.

(o) Measure the fuel pressure.

Standard Fuel Pressure:

196 to 833 kPa (2.0 to 8.5 kgf/cm2, 28 to 121 psi)

• If the fuel pressure is less than the standard, check the fuel hoses and their connections, fuel pump, fuel filter and fuel main valve assembly.
• If the result is not as specified, replace the fuel main valve assembly.

(p) Disconnect the Techstream from the DLC3.

(q) Start the engine.

(r) Measure the fuel pressure at idle.

Standard Fuel Pressure:

196 to 833 kPa (2.0 to 8.5 kgf/cm2, 28 to 121 psi)

HINT:

Refer to Standard Idle Speed.

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(s) Stop the engine.

(t) Check that the fuel pressure remains as specified for 5 minutes.

Standard Fuel Pressure:

98 kPa (1.0 kgf/cm2, 14.2 psi) or more

If the result is not as specified, check the fuel pump, fuel main valve assembly and/or fuel injector assemblies.

(u) After checking the fuel pressure, disconnect the cable from the negative (-) battery terminal and carefully remove SST to prevent fuel from spraying.

NOTICE:

When disconnecting the cable, some systems need to be initialized after the cable is reconnected.

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(v) Connect the fuel tube sub-assembly (for Port Injection).

(1) Connect the fuel tube sub-assembly to the fuel pipe.

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(w) Connect the No. 2 fuel tube sub-assembly (for Direct Injection).

(1) Connect the No. 2 fuel tube sub-assembly to the fuel pipe.

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(x) Install the No. 1 fuel pipe clamp to the fuel tube connector.

(y) Engage the 2 claws to install the No. 2 fuel pipe clamp.

(z) Inspect for fuel leaks.

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3. CHECK FUEL PRESSURE (for High Pressure)

(a) Connect the Techstream to the DLC3.

(b) Turn the engine switch on (IG).

(c) Turn the Techstream on.

(d) Enter the following menus: Powertrain / Engine / Data List / Engine Speed, Coolant Temperature, Fuel Pressure (High) and Injection Mode.

(e) Start the engine and warm it up until the engine coolant temperature is 75°C (167°F) or higher with all the accessories switched off.

(f) According to the display on the Techstream, read the Data List.

Standard:

If the result is not as specified, check the fuel pump, fuel pump assembly, fuel pressure sensor (fuel delivery pipe with sensor assembly LH) (for High Pressure) and wire harnesses.

(g) Stop the engine.

Parts Location

PARTS LOCATION

ILLUSTRATION

ILLUSTRATION

Precaution

PRECAUTION

CAUTION:

• Never perform work on fuel system components near any possible ignition sources.
• Vaporized fuel could ignite, resulting in a serious accident.
• Do not perform work on fuel system components without first disconnecting the cable from the negative (-) battery terminal.
• Sparks could cause vaporized fuel to ignite, resulting in a serious accident.
• The fuel tank assembly is very heavy. Be sure to follow the procedure described in the repair manual, or the fuel tank assembly may fall off the engine lifter.
• To prevent serious injury due to fuel spray from the high-pressure fuel lines, always discharge fuel system pressure before removing any fuel system components.

BEFORE WORKING ON FUEL SYSTEM

(a) Before inspecting and repairing the fuel system, disconnect the cable from the negative (-) battery terminal.

NOTICE:

After turning the engine switch off, waiting time may be required before disconnecting the cable from the negative (-) battery terminal. Therefore, make sure to read the disconnecting the cable from the negative (-) battery terminal notices before proceeding with work.

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(b) Do not smoke or work near fire when handling the fuel system.

(c) Keep fuel away from rubber or leather parts.

DISCHARGE FUEL SYSTEM PRESSURE

CAUTION:

• Make sure the engine coolant temperature is 60°C (140°F) or less when performing this procedure.
• Do not disconnect any part of the fuel system until you have discharged the fuel system pressure.
• Pressure will still remain in the fuel lines even after performing the following procedure. When disconnecting a fuel line, cover it with a piece of cloth to prevent fuel from spraying or coming out.

(a) When discharging fuel system pressure by disconnecting the EFI-MAIN NO. 2 relay:

(1) Remove the No. 1 engine room relay block and No. 1 junction block assembly cover.

(2) Remove the EFI-MAIN NO. 2 relay.

(3) Remove the V-bank cover sub-assembly.

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(4) Disconnect the No. 6 engine wire connector and No. 7 engine wire connector.

(5) Start the engine. After the engine has stopped on its own, turn the engine switch off.

NOTICE:

Do not increase the engine speed or drive the vehicle while waiting for the engine to stop on its own.

(6) Crank the engine again and make sure that the engine does not start.

HINT:

DTC P008700 (Fuel Rail / System Pressure - Too Low), P017100/P017400 (System Too Lean), P160300 (Engine Stall History), P160400 (Startability Malfunction) or P160500 (Rough Idling) may be stored. Clear the DTCs before proceeding to the next step.

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(7) Remove the fuel tank cap assembly and discharge the pressure from the fuel tank assembly.

(8) Disconnect the cable from the negative (-) battery terminal.

NOTICE:

When disconnecting the cable, some systems need to be initialized after the cable is reconnected.

Click here

(9) Connect the No. 6 engine wire connector and No. 7 engine wire connector.

(10) Install the V-bank cover sub-assembly.

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(11) Install the EFI-MAIN NO. 2 relay.

(12) Install the No. 1 engine room relay block and No. 1 junction block assembly cover.

(b) When discharging fuel system pressure by disconnecting the fuel pump connector:

(1) Disconnect the rear center seat outer belt assembly.

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(2) Remove the rear seat cushion assembly.

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(3) Remove the rear seat cushion lock hook.

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(4) Using a clip remover with its tip wrapped with protective tape, remove the rear floor service hole cover and butyl tape.

(5) Disconnect the fuel pump connector.

(6) Remove the V-bank cover sub-assembly.

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(7) Disconnect the No. 6 engine wire connector and No. 7 engine wire connector.

(8) Start the engine. After the engine has stopped on its own, turn the engine switch off.

NOTICE:

Do not increase the engine speed or drive the vehicle while waiting for the engine to stop on its own.

(9) Crank the engine again and make sure that the engine does not start.

HINT:

DTC P008700 (Fuel Rail / System Pressure - Too Low), P017100/P017400 (System Too Lean), P160300 (Engine Stall History), P160400 (Startability Malfunction) or P160500 (Rough Idling) may be stored. Clear the DTCs before proceeding to the next step.

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(10) Remove the fuel tank cap assembly and discharge the pressure from the fuel tank assembly.

(11) Disconnect the cable from the negative (-) battery terminal.

NOTICE:

When disconnecting the cable, some systems need to be initialized after the cable is reconnected.

Click here

(12) Connect the No. 6 engine wire connector and No. 7 engine wire connector.

(13) Install the V-bank cover sub-assembly.

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(14) Remove any remaining butyl tape from the rear floor service hole cover and vehicle body.

(15) Clean the installation surfaces of the rear floor service hole cover and vehicle body.

(16) Connect the fuel pump connector.

(17) Install the rear floor service hole cover with new butyl tape.

NOTICE:

Securely install the rear floor service hole cover.

(18) Install the rear seat cushion lock hook.

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(19) Install the rear seat cushion assembly.

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(20) Connect the rear center seat outer belt assembly.

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FUEL LINE

(a) When disconnecting a high-pressure fuel line, a large amount of fuel will spray. Perform the following procedure:

(1) Discharge fuel system pressure.

(2) Disconnect the fuel tube.

(3) Drain the fuel remaining inside the fuel pump tube into a container.

(4) Cover the disconnected fuel pipe and fuel tube connector with plastic bags to prevent damage and contamination.

(b) Quick Type A:

Perform the following procedure when disconnecting a fuel tube connector.

NOTICE:

Remove any foreign matter on the fuel tube connector and fuel pipe before performing this work.

(1) Disengage the 2 claws to remove the No. 2 fuel pipe clamp.

(2) Remove the No. 1 fuel pipe clamp from the fuel tube connector.

(3) Check that there is no foreign matter around the fuel tube connector before disconnecting it. Clean it if necessary.

(4) While holding the retainer at the positions shown in the illustration, pull up the retainer to disengage the lock claws.

*a	Retainer
	Retainer Holding Position
	Pull out

HINT:

If the lock claws of the retainer are difficult to disengage, disengage them using a screwdriver with its tip wrapped with protective tape.

(5) Pull up the retainer while holding it at the positions shown in the illustration and pull off the fuel tube connector.

*a	Retainer
*b	O-ring
*c	Fuel Tube Connector
*d	Nylon Tube
*e	Fuel Pipe
	Retainer Holding Position
	Pull out
	Pull off

(6) If the fuel tube connector and fuel pipe are stuck, push and pull the fuel tube connector to release it. Pull the fuel tube connector off of the fuel pipe carefully.

NOTICE:

• Do not scratch or allow any foreign matter to get on the parts when disconnecting them as the fuel tube connector has O-rings that seal the pipe (fuel pipe).
• Do not bend, twist, pinch or kink the nylon tube.

(7) Check that there is no foreign matter on the sealing surfaces of the disconnected fuel lines. Clean them if necessary.

(8) Cover the disconnected fuel pipe and fuel tube connector with plastic bags to prevent damage and contamination.

(c) Quick Type A:

Perform the following procedure when connecting a fuel tube connector.

NOTICE:

Check that there is no damage or foreign matter on the connecting parts of the fuel lines.

(1) Align the fuel tube connector with the fuel pipe, push the fuel tube connector onto the fuel pipe, then push in the retainer to secure the connection.

*a	Retainer
	Push
	Push in

NOTICE:

Confirm that the retainer makes a "click" sound when pushed.

HINT:

If it is difficult to push the fuel tube connector onto the fuel pipe, apply a small amount of clean gasoline to the tip of the fuel pipe.

(2) After connecting the fuel lines, check that the fuel pipe and fuel tube connector are securely connected by pulling on them.

(3) Install the No. 1 fuel pipe clamp to the fuel tube connector.

(4) Engage the 2 claws to install the No. 2 fuel pipe clamp.

(5) Inspect for fuel leaks.

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(d) Quick Type B:

Perform the following procedure when disconnecting a fuel tube connector.

NOTICE:

Remove any foreign matter on the fuel tube connector and fuel pipe before performing this work.

(1) Pull out the retainer to disengage the lock claws and pull off the fuel tube connector.

*a	Retainer
*b	Fuel Pipe
*c	Fuel Tube Connector
*d	O-ring
	Pull out
	Pull off

(2) If the fuel tube connector and fuel pipe are stuck, push and pull the fuel tube connector to release it. Pull the fuel tube connector off of the fuel pipe carefully.

NOTICE:

Do not scratch or allow any foreign matter to get on the parts when disconnecting them as the fuel tube connector has an O-ring that seals the pipe (fuel pipe).

(3) Check that there is no foreign matter on the sealing surfaces of the disconnected fuel lines. Clean them if necessary.

(4) Cover the disconnected fuel pipe and fuel tube connector with plastic bags to prevent damage and contamination.

(e) Quick Type B:

Perform the following procedure when connecting a fuel tube connector.

NOTICE:

Check that there is no damage or foreign matter on the connecting parts of the fuel lines.

(1) Align the fuel tube connector with the fuel pipe, push the fuel tube connector onto the fuel pipe, then push in the retainer to secure the connection.

*a	Retainer
	Push
	Push in

NOTICE:

Confirm that the retainer makes a "click" sound when pushed.

HINT:

If it is difficult to push the fuel tube connector onto the fuel pipe, apply a small amount of clean gasoline to the tip of the fuel pipe.

(2) After connecting the fuel lines, check that the fuel pipe and fuel tube connector are securely connected by pulling on them.

(3) Inspect for fuel leaks.

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(f) Quick Type C:

Perform the following procedure when disconnecting a fuel tube connector.

NOTICE:

Remove any foreign matter on the fuel tube connector and fuel pipe before performing this work.

(1) Pull out the retainer to disengage the lock claws and pull off the fuel tube connector.

*a	Retainer
	Pull out
	Pull off

(2) If the fuel tube connector and fuel pipe are stuck, push and pull the fuel tube connector to release it. Pull the fuel tube connector off of the fuel pipe carefully.

NOTICE:

Do not scratch or allow any foreign matter to get on the parts when disconnecting them as the fuel tube connector has O-rings that seal the pipe (fuel pipe).

(3) Check that there is no foreign matter on the sealing surfaces of the disconnected fuel lines. Clean them if necessary.

(4) Cover the disconnected fuel pipe and fuel tube connector with plastic bags to prevent damage and contamination.

(g) Quick Type C:

Perform the following procedure when connecting a fuel tube connector.

NOTICE:

Check that there is no damage or foreign matter on the connecting parts of the fuel lines.

(1) Align the fuel tube connector with the fuel pipe, push the fuel tube connector onto the fuel pipe, then push in the retainer to secure the connection.

*a	Retainer
	Push
	Push in

NOTICE:

Confirm that the retainer makes a "click" sound when pushed.

HINT:

If it is difficult to push the fuel tube connector onto the fuel pipe, apply a small amount of clean gasoline to the tip of the fuel pipe.

(2) After connecting the fuel lines, check that the fuel pipe and fuel tube connector are securely connected by pulling on them.

(3) Inspect for fuel leaks.

Click here

(h) Quick Type D:

Perform the following procedure when disconnecting a fuel tube connector.

NOTICE:

Remove any foreign matter on the fuel tube connector and fuel pipe before performing this work.

(1) Pull out the retainer to disengage the lock claws and pull off the fuel tube connector.

*a	Retainer
*b	O-ring
*c	Fuel Tube Connector
*d	Fuel Pipe
	Pull out
	Pull off

(2) If the fuel tube connector and fuel pipe are stuck, push and pull the fuel tube connector to release it. Pull the fuel tube connector off of the fuel pipe carefully.

NOTICE:

Do not scratch or allow any foreign matter to get on the parts when disconnecting them as the fuel tube connector has O-rings that seal the pipe (fuel pipe).

(3) Check that there is no foreign matter on the sealing surfaces of the disconnected fuel lines. Clean them if necessary.

(4) Cover the disconnected fuel pipe and fuel tube connector with plastic bags to prevent damage and contamination.

(i) Quick Type D:

Perform the following procedure when connecting a fuel tube connector.

NOTICE:

Check that there is no damage or foreign matter on the connecting parts of the fuel lines.

(1) Align the fuel tube connector with the fuel pipe, push the fuel tube connector onto the fuel pipe, then push in the retainer to secure the connection.

*a	Retainer
*b	90°
*c	45°
*d	Up
	Push
	Push in

NOTICE:

Confirm that the retainer makes a "click" sound when pushed.

HINT:

• If it is difficult to push the fuel tube connector onto the fuel pipe, apply a small amount of clean gasoline to the tip of the fuel pipe.
• Make sure the retainer is positioned within the area shown in the illustration.

(2) After connecting the fuel lines, check that the fuel pipe and fuel tube connector are securely connected by pulling on them.

(3) Inspect for fuel leaks.

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(j) Observe the following precautions when handling a nylon tube:

NOTICE:

• Do not twist the nylon tube of the fuel tube connector or fuel tube connector when connecting it.
• Do not remove the Ethylene Propylene Diene Monomer (EPDM) rubber protector on the outside of the nylon tube.
• Do not bend, twist, pinch or kink the nylon tube.

FUEL SUCTION TUBE WITH PUMP AND GAUGE ASSEMBLY

NOTICE:

• Do not disconnect the tube shown in the illustration when disassembling the fuel suction tube with pump and gauge assembly. Doing so will cause reassembly of the fuel suction tube with pump and gauge assembly to be impossible as the tube is pressed into the fuel suction plate sub-assembly.

  *a

  Tube

• When replacing the fuel filter, replace it together with the fuel suction plate sub-assembly.

INSPECT FOR FUEL LEAK

(a) Check that there are no fuel leaks from the fuel system after doing any maintenance or repairs.

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System Diagram

SYSTEM DIAGRAM

FUEL FLOW DIAGRAM

ELECTRICAL CONTROL DIAGRAM

HIGH PRESSURE SIDE FUEL SYSTEM WIRING DIAGRAM

LOW PRESSURE SIDE FUEL SYSTEM WIRING DIAGRAM