2006 Scion tC AutomaticFACTORY OEM SERVICE PROCEDURE

Typical Malfunction Thresholds: Wiring Diagram

Fig 1: Throttle Actuator Control Motor Circuit - Wiring Diagram
G04221172Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

HINT:

  • Read freeze frame data using the intelligent tester. Freeze frame data records the engine conditions when a malfunction is detected. When troubleshooting, freeze frame data can help determine if the vehicle was running or stopped, 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.
  • The throttle actuator current (THROTTLE MOT) and the throttle actuator duty ratio (THROTTLE OPN / THROTTLE CLS) can be read using the intelligent tester. However, the ECM shuts off the throttle actuator current when the ETCS malfunctions.
  1. INSPECT THROTTLE BODY (THROTTLE ACTUATOR RESISTANCE) 
    1. Disconnect the T1 throttle body connector.
    2. Measure the resistance of the throttle actuator.

    Standard resistance 

    TESTER CONNECTION SPECIFIED CONDITION CHART

    Tester Connection Specified Condition
    M+ (2) - M- (1) 0.3 and 100 Ω at 20°C (68°F)

    NG : REPLACE THROTTLE BODY 

    Fig 2: Identifying T1 Throttle Body Connector Terminals
    G04221173Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    OK : Go to next Step 

  2. CHECK WIRE HARNESS (THROTTLE ACTUATOR - ECM) 
    1. Disconnect the T1 throttle body connector.
    2. Disconnect the E6 ECM connector.
    3. Measure the resistance of the wire harness side connectors.

    Standard resistance 

    TESTER CONNECTION SPECIFIED CONDITION CHART

    Tester Connection Specified Condition
    M+ (T1-2) - M+ (E6-3) Below 1 Ω
    M- (T1-1) - M- (E6-2) Below 1 Ω
    M+ (T1-2) or M+ (E6-3) - Body ground 10 kΩ or higher
    M- (T1-1) or M- (E6-2) - Body ground 10 kΩ or higher

    NG : REPAIR OR REPLACE HARNESS AND CONNECTOR 

    Fig 3: Disconnecting E6 ECM Connector
    G04221174Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    OK : Go to next Step 

  3. INSPECT THROTTLE BODY 
    1. Check for foreign objects between the throttle valve and the housing.

    NG : REMOVE FOREIGN OBJECT AND CLEAN THROTTLE BODY 

    OK : Go to next Step 

  4. INSPECT THROTTLE VALVE 
    1. Check if the throttle valve opens and closes smoothly.

    NG : REPLACE THROTTLE BODY 

    OK : REPLACE ECM 

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • • You smell fuel, burning insulation, or see smoke.
  • • Brakes feel soft, pull hard to one side, or make grinding noises.
  • • The engine overheats, stalls repeatedly, or misfires under load.
  • • You are missing required tools, torque specs, or safe lifting equipment.
  • • You are not confident in the next step or safety outcome.

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