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Home >> Chevrolet >> 2004 >> Optra Base, Standard >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - 1.4L DOHC - DTC P1402 To DTC P1661 >> DTC P1511 >> Circuit Description

Circuit Description

The throttle body assembly contains an idle speed control (ISC) motor that is used to control the engine speed at idle. The engine control module (ECM) commands the ISC motor to adjust the throttle angle for idle speed control. An idle switch is also integrated into the throttle body assembly. The idle switch position is dependent upon the position of the throttle. The ECM uses a high and low control circuit to command the ISC motor. If the ECM detects a fault with the ISC motor control circuits or motor, this DTC sets.