Toyota Corolla Cross: Idle Control System (P050500)

DESCRIPTION

The idle speed is controlled by the electronic throttle control system. The electronic throttle control system is comprised of: 1) one valve type throttle body with motor assembly; 2) the throttle actuator, which operates the throttle valve; 3) the throttle position sensor, which detects the opening angle of the throttle valve; 4) the accelerator pedal position sensor, which detects the accelerator pedal position; 5) the ECM, which controls the electronic throttle control system. Based on the target idle speed, the ECM controls the throttle actuator to provide the proper throttle valve opening angle.

MONITOR DESCRIPTION

The ECM monitors the idle speed and idling air flow volume to conduct idle speed control. The ECM determines that the idle speed control system is malfunctioning if either of the following conditions is met:

• The difference between the target engine idle speed and actual engine idle speed exceeds the threshold and the idle control correction value is stuck at the upper or lower limit for 5 seconds or more.
• After driving at a vehicle speed of 10 km/h (6.25 mph) or more, the difference between the target and actual engine idle speed exceeds the threshold 5 times or more during a driving cycle, and then the system determines that the idle control correction value is stuck at the upper or lower limit, or that the idle control correction value has been changed by an amount that exceeds the threshold.

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 GTS to the DLC3.
2. Turn the ignition switch to ON.
3. Turn the GTS on.
4. Clear the DTCs (even if no DTCs are stored, perform the clear DTC procedure).
5. Turn the ignition switch off and wait for at least 30 seconds.
6. Turn the ignition switch to ON [A].
7. Turn the GTS on.
8. Start the engine and warm it up until the engine coolant temperature is 75°C (167°F) or higher with the A/C switch and all the accessories off [B].
9. Idle the engine for 5 minutes or more [C].

   HINT:

   In order to keep the idling stable, turn off the A/C and all other electric loads and do not perform any shift operations.

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: P050500.
14. Check the DTC judgment result.

    GTS 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.
    • If the judgment result is INCOMPLETE, perform steps [E] through [F].
    • [A] to [D]: 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 auxiliary battery terminal or attempt to clear the DTCs during this procedure, as doing so will clear the universal trip and normal judgment histories.
15. Accelerate the vehicle to 10 km/h (6.25 mph) or more, and then idle the engine for 20 seconds or more [E].

    CAUTION:

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

16. Repeat step [E] 5 times.
17. Enter the following menus: Powertrain / Engine / Trouble Codes [F].
18. 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.
19. Enter the following menus: Powertrain / Engine / Utility / All Readiness.
20. Input the DTC: P050500.
21. Check the DTC judgment result.

    GTS 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 [F]: 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 auxiliary battery terminal or attempt to clear the DTCs during this procedure, as doing so will clear the universal trip and normal judgment histories.

CAUTION / NOTICE / HINT

HINT:

• The following conditions may also cause DTC P050500 to be stored:
  1. If the floor carpet or floor mat is resting slightly on the accelerator pedal, causing the accelerator pedal to be slightly depressed and therefore the throttle valve position to be slightly open.
  2. The accelerator pedal is not fully released.
• Refer to "Data List / Active Test" [Engine Speed, ISC F/B Learn Torque and ISC F/B Torque].

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• Read Freeze Frame Data using the GTS. 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) Read the DTCs.

HINT:

If any DTCs other than P050500 are output, troubleshoot those DTCs first.

B

GO TO DTC CHART

A

(a) Check the PCV hose connections.

(b) Check the PCV valve.

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OK:

PCV hose and PCV valve are connected correctly and are not damaged.

NG

REPAIR OR REPLACE PCV VALVE OR HOSE

OK

(a) Check the intake system for vacuum leaks.

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OK:

No leaks from the intake system.

HINT:

Perform "Inspection After Repair" after repairing or replacing the intake system.

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NG

REPAIR OR REPLACE INTAKE SYSTEM

OK

(a) Start the engine and warm it up until the engine coolant temperature is 75°C (167°F) or higher.

HINT:

The A/C switch and all accessories should be off.

(b) Enter the following menus.

(c) Check the engine idling condition and Intake Manifold Absolute Pressure values in the Data List while performing the Active Test.

NOTICE:

• Do not leave the EGR valve open for 10 seconds or more during the Active Test.
• Be sure to return the EGR valve to step 0 when the Active Test is completed.
• Do not open the EGR valve 30 steps or more during the Active Test.

OK:

The value of Intake Manifold Absolute Pressure and Engine Speed change in response to EGR step position.

Standard:

HINT:

During Active Test, if the idling condition does not change in response to EGR step position, then there is probably a malfunction in the EGR valve.

OK

GO TO STEP 6

NG

(a) Remove the EGR valve assembly.

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(b) Check if the EGR valve is stuck open.

OK:

EGR valve is tightly closed.

HINT:

Perform "Inspection After Repair" after replacing the EGR valve assembly.

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NG

REPLACE EGR VALVE ASSEMBLY

OK

(a) Check the throttle body with motor assembly condition.

OK:

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

HINT:

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

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NG

REPLACE THROTTLE BODY WITH MOTOR ASSEMBLY

OK

(a) Clear the DTCs.

(b) Turn the ignition 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) Read the pending DTCs.

A

END

B

REPLACE ECM

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