Circuit/System Description
WARNING: This page is about a different car, the 2008 Buick LaCrosse and 2008 Buick Allure. However, it is still accessible from the selected car via links, so may be relevant.
The commanded throttle position (TP), based on accelerator pedal position (APP), is compared to the actual throttle position. The TP values should be within a calibrated range of each other. The throttle actuator control (TAC) module monitors the commanded and the actual throttle position. If the TAC module detects that the commanded and actual throttle positions are not within a calibrated range of each other, the TAC module or the powertrain control module (PCM) cannot determine throttle position, or if both TP sensors are invalid, a message is sent to the PCM across serial data and DTC P1516 is set.