LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Scion >> 2009 >> xB Automatic >> Repair and Diagnosis >> Electrical >> Body Electrical >> OEM System Circuits >> Engine Control >> System Outline >> Input Signals
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Input Signals

  1. Engine coolant temperature signal circuit

    The engine coolant temperature sensor detects the engine coolant temperature and has a built-in thermistor with a resistance which varies according to the engine coolant temperature. The engine coolant temperature is input into TERMINAL THW of the engine control module as a control signal.

  2. Intake air temperature signal circuit

    The intake air temperature sensor is installed in the mass air flow meter and detects the intake air temperature which is input as a control signal to TERMINAL THA of the engine control module.

  3. Vehicle speed signal circuit

    The vehicle speed signal is input from the speed sensor to the skid control ECU with actuator, and is sent to the engine control module through communication control.

  4. RPM signal circuit

    The engine RPM is detected by the crankshaft position sensor installed in the cylinder block and the signal is input into TERMINAL NE+ of the engine control module as a control signal.

  5. Throttle position signal circuit

    The throttle position sensor detects the throttle valve opening angle as a control signal, which is input into TERMINALS VTA1 and VTA2 of the engine control module.

  6. Battery signal circuit

    Voltage is constantly applied to TERMINAL BATT of the engine control module. When the ignition Switch is turned on, the voltage for engine control module start-up power supply is applied to TERMINALS +B and +B2 of the engine control module via the EFI MAIN relay.

    The current flowing through the IGN fuse flows to TERMINAL IGSW of the engine control module.

  7. Intake air volume signal circuit

    Intake air volume is detected by the mass air flow meter and the signal is input to TERMINAL VG of the engine control module as a control signal.

  8. Stop light switch signal circuit

    The stop light switch is used to detect whether the vehicle is braking or not and the signal is input into TERMINAL STP of the engine control module as a control signal.

  9. Starter signal circuit

    To confirm whether the engine is cranking, the voltage which is being applied to the starter motor during cranking is detected and the signal is input into TERMINAL STA of the engine control module as a control signal.

  10. Engine knock signal circuit

    Engine knocking is detected by knock sensor and the signal is input into TERMINAL KNK1 as a control signal.

  11. Air fuel ratio signal system

    The air fuel ratio is detected and input as a control signal into TERMINAL A1A+ of the engine control module.

  12. Oxygen sensor signal circuit

    The oxygen density in the exhaust gases is detected and input as a control signal into TERMINAL OX1B of the engine control module. To maintain stable detection performance by the heated oxygen sensor, a heater is used for warning the sensor. The heater is also controlled by engine control module.