Circuit Description

The throttle actuator control (TAC) motor is controlled by the engine control module (ECM). The DC motor located in the throttle body drives the throttle plate. In order to decrease idle speed, the ECM commands the throttle closed, which reduces air flow into the engine. In order to increase idle speed, the ECM commands the throttle plate open, which allows more air flow into the engine. If the actual idle RPM does not match the desired idle RPM within a calibrated time, DTC P0507 sets.