Drive By Wire System
The Drive By Wire System is an electronic throttle control system. This system consists of the throttle valve control motor and Throttle Position (TP) sensor assembled in Throttle Body (TB), the accelerator position sensor, and the Engine Control Module (ECM).
When the engine is idling, the ECM controls the throttle valve control motor to maintain the proper idle speed according to engine loads. When the accelerator pedal is depressed, the ECM opens the throttle valve depending on the accelerator position sensor signals. The ECM controls the throttle valve control motor to maintain the set speed when the cruise control system is operating. The throttle valve control motor takes the place of the cruise control actuator. If wheel spin occurs during acceleration or cornering, the Traction Control System (TCS) control unit requests the ECM to reduce the engine power by retarding the ignition timing and closing the throttle valve. If the wheels lock during deceleration, the TCS control unit signals the ECM to open the throttle valve. When the engine speed exceeds 8,000 RPM (M/T) or 7,500 RPM (A/T), the ECM controls the throttle valve, regardless of the accelerator position, to protect the engine from over-revving.
On this system, the ECM monitors the position of the accelerator pedal with a dual circuit type accelerator position sensor, and monitors the operation of the throttle valve control motor with a Throttle Position (TP) sensor. When an abnormality occurs in the system, the ECM restricts the operation of the throttle valve control motor to allow the engine to continue to run. See Fig 1 .