ELECTRONIC THROTTLE CONTROL OPERATION [L8, LF, L3]

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Target Throttle Valve Opening Angle Calculation

• The PCM calculates the target throttle valve opening angle based on signals from accelerator pedal position (APP) sensors No.1 and No.2.

• In order to change the actual throttle valve opening angle to the calculated target opening angle, the PCM controls the direction and size of the current sent to the throttle actuator.

• Throttle position (TP) sensors No.1 and No.2 detect the actual throttle valve opening angle.

Throttle Valve Opening Angle Learning

• After the ignition switch is turned off, the PCM opens and closes the throttle valve. At this time, the input voltage of the TP sensor at the fully closed position and the fully open position is stored.

• This learned voltage measurement at the fully closed and open position is used when correcting the throttle opening angle. (See IDLE AIR CONTROL (IAC) OUTLINE [L8, LF, L3].)

Fail-safe

• If the PCM detects any of the following malfunctions, it limits the throttle valve opening angle, performs fuel cut and other control measures to limit engine output, as well as stopping the flow of electricity to the throttle actuator. When this flow of electricity is stopped, the throttle valve is limited to the minimum opening angle possible for driving:

- TP sensor No.1 malfunction

- TP sensor No.2 malfunction

- APP sensor No.1 malfunction

- APP sensor No.2 malfunction

- Throttle actuator malfunction

- PCM internal circuit (for electronic throttle control) malfunction

- Throttle body (throttle valve and return spring) malfunction