DTC B1647 KIA

Description

GENERAL OPERATION: The Electronic Throttle Control (ETC) Motor is controlled using an H-Bridge circuit inside the Powertrain Control Module (PCM). An H-Bridge is an electronic circuit that enables a voltage to be applied across a load in either direction. The H-Bridge arrangement is generally used to reverse the polarity direction of the DC motor which allows the DC motor to run forward and backwards. The DC motor located in the Throttle Body drives the throttle blade. In order to decrease engine speed, along with spark and fuel delivery changes, the PCM commands the throttle blade closed reducing air flow into the engine and the engine speed decreases. In order to increase engine speed, the PCM commands the throttle blade open, increasing air flow and engine speed. On a normally functioning Throttle Body, the duty cycle of the ETC Motor should not go above approximately 40%. See the figure below for a general configuration and operation of an H-Bridge:An H-Bridge circuit is built with four solid-state switches. When the switches S1 and S4 are closed and S2 and S3 are open (left) a positive voltage will be applied across the motor. Opening S1 and S4 switches and closing S2 and S3 switches (right) will allow the motor to reverse operation. Click to Enlarge