Toyota Avalon (XX50) 2019-2022 Service & Repair Manual: Throttle Actuator "A" Control System Actuator Stuck Open (P211172,P211173)

DESCRIPTION

The throttle actuator is operated by the ECM, and opens and closes the throttle valve using gears. The opening angle of the throttle valve is detected by the throttle position sensor, which is mounted on the throttle body with motor assembly. The throttle position sensor provides feedback to the ECM. This feedback allows the ECM to appropriately control the throttle actuator and monitor the throttle opening angle as the ECM responds to driver inputs.

HINT:

This Electronic Throttle Control System (ETCS) does not use a throttle cable.

MONITOR DESCRIPTION

The ECM determines that there is a malfunction in the ETCS when the throttle valve remains at a fixed angle despite a high drive current from the ECM. The ECM then illuminates the MIL and stores a DTC.

MONITOR STRATEGY

TYPICAL ENABLING CONDITIONS

TYPICAL MALFUNCTION THRESHOLDS

CONFIRMATION DRIVING PATTERN

HINT:

• After repair has been completed, clear the DTC and then check that the vehicle has returned to normal by performing the following All Readiness check procedure.

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• When clearing the permanent DTCs, refer to the "CLEAR PERMANENT DTC" procedure.

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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 fully depress and release the accelerator pedal quickly (to fully open and close the throttle valve) [B].
9. Enter the following menus: Powertrain / Engine / Trouble Codes [C].
10. 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.
11. Enter the following menus: Powertrain / Engine / Utility / All Readiness.
12. Input the DTC: P211172 or P211173.
13. 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 is malfunctioning.
    • [A] to [C]: Normal judgment procedure.

      The normal judgment procedure is used to complete DTC judgment and also used when clearing permanent DTCs.

    • When clearing the permanent DTCs, do not disconnect the cable from the battery terminal or attempt to clear the DTCs during this procedure, as doing so will clear the universal trip and normal judgment histories.

FAIL-SAFE

When any of these DTCs or other DTCs relating to Electronic Throttle Control System (ETCS) malfunctions are stored, the ECM enters fail-safe mode. During fail-safe mode, the ECM cuts the current to the throttle actuator, and the throttle valve is returned to a 7° throttle valve opening angle by the return spring. The ECM then adjusts the engine output by controlling the fuel injection (intermittent fuel-cut) and ignition timing, in accordance with the accelerator pedal opening angle, to allow the vehicle to continue running at a minimal speed. If the accelerator pedal is depressed firmly and gently, the vehicle can be driven slowly.

Fail-safe mode continues until a pass condition is detected, and the engine switch is then turned off.

WIRING DIAGRAM

Refer to DTC P210014.

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CAUTION / NOTICE / HINT

HINT:

• Refer to "Data List / Active Test" [Throttle Position Command, Throttle Position Sensor No.1 Voltage, Throttle Position Sensor No.2 Voltage, Throttle Motor Current, Throttle Motor Duty Ratio (Open) and Throttle Motor Duty Ratio (Close)].

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• 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 P211172 or P211173 are output, troubleshoot those DTCs first.

B

GO TO DTC CHART

A

(a) Check for contamination between the throttle valve and housing. If necessary, clean the throttle body with motor assembly. Also check that the throttle valve moves smoothly.

OK:

Throttle valve is not contaminated with foreign matter and moves smoothly.

HINT:

Perform "Inspection After Repair" after cleaning the throttle body with motor assembly.

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NG

GO TO STEP 6

OK

(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) Turn the engine switch on (IG).

(b) Turn the Techstream on.

(c) Enter the following menus: Powertrain / Engine / Data List / Throttle Position Sensor No.1 Voltage, Throttle Position Sensor No.2 Voltage and Throttle Position Command.

(d) Read the values displayed on the Techstream while wiggling the ECM wire harness.

(e) Enter the following menus: Powertrain / Engine / Trouble Codes.

(f) Read the DTCs

B

GO TO STEP 7

A

(a) As the DTC was stored due to a change in the contact resistance of the connector, repair or replace the wire harness or connector.

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NEXT

END

(a) Replace the throttle body with motor assembly.

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HINT:

Perform "Inspection After Repair" after replacing the throttle body with motor assembly.

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NEXT

(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 / Trouble Codes.

(c) Read the DTCs.

A

END

B

REPLACE ECM