LEMON Manuals: Even more car manuals for everyone
Home >> Cadillac >> 2004 >> CTS Base, 3.2 N >> Repair and Diagnosis >> External Pages >> Different variant/trim >> Section 20 (Engine Controls - 3.6L - Diagnosis (DTC P0351 - P1014)) >> Diagnosis >> DTC P0638 >> Circuit Description

Circuit Description

WARNING: This page is about a different variant/trim than selected.

The engine control module (ECM) controls the throttle valve by applying a varying voltage to the control circuits of the throttle actuator control (TAC) motor. The ECM monitors the duty cycle that is required to actuate the throttle valve. The ECM monitors the throttle position (TP) sensors 1 and 2 to determine the actual throttle valve position. If the ECM detects that the duty cycle to control the throttle valve to the desired position is more than a predetermined value, this DTC sets.