Toyota Avalon (XX50) 2019-2022 Service & Repair Manual: Low Pressure Fuel System Pressure - Too High (P008B00)

DESCRIPTION

Refer to DTC P008A00.

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MONITOR DESCRIPTION

If the fuel pressure (for low pressure side) increases despite a decrease request signal being sent to the fuel pump control ECU by the ECM, the ECM will store this DTC.

MONITOR STRATEGY

CONFIRMATION DRIVING PATTERN

1. Connect the Techstream to the DLC3.
2. Turn the engine switch on (IG).
3. Turn the Techstream on.
4. Clear the DTCs (even if no DTCs are stored, perform the clear DTC procedure).
5. Turn the engine switch off and wait for at least 30 seconds.
6. Turn the engine switch on (IG) [A].
7. Turn the Techstream on.
8. Start the engine and warm it up until the engine coolant temperature reaches 75°C (167°F) or higher [B].
9. Drive the vehicle for 15 minutes or more [C].

   CAUTION:

   When performing the confirmation driving pattern, obey all speed limits and traffic laws.

10. Enter the following menus: Powertrain / Engine / Trouble Codes [D].
11. Read the pending DTCs.

    HINT:

    • If a pending DTC is output, the system is malfunctioning.
    • If a pending DTC is not output, perform the following procedure.
12. Enter the following menus: Powertrain / Engine / Utility / All Readiness.
13. Input the DTC: P008B00.
14. Check the DTC judgment result.

    Techstream Display	Description
    NORMAL	DTC judgment completed System normal
    ABNORMAL	DTC judgment completed System abnormal
    INCOMPLETE	DTC judgment not completed Perform driving pattern after confirming DTC enabling conditions

    HINT:

    • If the judgment result is NORMAL, the system is normal.
    • If the judgment result is ABNORMAL, the system has a malfunction.
    • If the judgment result is INCOMPLETE, perform steps [B] through [D] again.

CAUTION / NOTICE / HINT

HINT:

Read freeze frame data using the Techstream. The ECM records vehicle and driving condition information as freeze frame data the moment a DTC is stored. When troubleshooting, freeze frame data can help determine if the vehicle was moving or stationary, if the engine was warmed up or not, if the air fuel ratio was lean or rich, and other data from the time the malfunction occurred.

PROCEDURE

(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 / Trouble Codes.

(e) Read the DTCs.

HINT:

If any DTCs other than P008B00 are output, troubleshoot those DTCs first.

B

GO TO DTC CHART

A

(a) Connect the Techstream to the DLC3.

(b) Start the engine.

(c) Turn the Techstream on.

(d) Enter the following menus: Powertrain / Engine / Data List / Fuel Pressure (Low).

(e) Record the Fuel Pressure (Low) value.

(f) Turn the engine switch off.

(g) Discharge the fuel pressure.

HINT:

DTCs may be stored during this inspection. Check for DTCs and clear them using the Techstream.

(1) Remove the EFI-MAIN NO. 2 fuse from the No. 1 engine room relay block and No. 1 junction block assembly.

(2) Start the engine.

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

HINT:

If the engine does not stop naturally, perform direct injection by racing the engine to reduce the fuel pressure [Fuel Pressure (High)] and stop the engine.

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

(5) Install the EFI-MAIN NO. 2 fuse.

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

(i) Turn the Techstream on.

(j) Enter the following menus: Powertrain / Engine / Data List / Fuel Pressure (Low).

(k) Compare the Fuel Pressure (Low) value recorded with the engine running to the Fuel Pressure (Low) value currently shown on the Techstream.

HINT:

Perform "Inspection After Repair" after replacing the fuel pressure sensor (for low pressure side).

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B

REPLACE FUEL DELIVERY PIPE RH (FUEL PRESSURE SENSOR (FOR LOW PRESSURE SIDE))

A

(a) Install the fuel pressure gauge (for low pressure line of low pressure side).

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(b) Connect the Techstream to the DLC3.

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

(d) Turn the Techstream on.

(e) Enter the following menus: Powertrain / Engine / Active Test / Control the Fuel Pump Duty Ratio / Data List / Fuel Pressure (Low).

(f) Compare the values in the Data List using the Techstream and the fuel pressure gauge when the Active Test was performed.

Standard:

HINT:

Perform "Inspection After Repair" after replacing the fuel pressure sensor (for low pressure side).

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NG

REPLACE FUEL DELIVERY PIPE RH (FUEL PRESSURE SENSOR (FOR LOW PRESSURE SIDE))

OK

(a) Install the fuel pressure gauge (for low pressure line of low pressure side).

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(b) Connect the Techstream to the DLC3.

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

(d) Turn the Techstream on.

(e) Enter the following menus: Powertrain / Engine / Active Test / Control the Fuel Pump Duty Ratio / Data List / Fuel Pressure (Low).

(f) Read the values on the Data List and the fuel pressure gauge when the Active Test was performed.

B

REPLACE FUEL PUMP CONTROL ECU

A

(a) Connect the Techstream to the DLC3.

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

(c) Turn the Techstream on.

(d) Clear the DTC.

(e) Turn the engine switch off and wait for at least 30 seconds.

NEXT

(a) Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.

(b) Enter the following menus: Powertrain / Engine / Utility / All Readiness.

(c) Input the DTC: P008B00.

(d) Check the DTC judgment result.

A

CHECK FOR INTERMITTENT PROBLEMS

B

REPLACE ECM