Feedback Idle Speed Control

The ECU has a pre-programmed target idle speed which is maintained by the ISCV based on feedback from the Ne signal. Feedback idle speed control occurs any time the throttle is closed and the engine is at normal operating temperature. The target idle speed is programmed in an ECU look up table and varies depending on inputs from the A/C and NSW signals. Any time actual speed varies by greater than 20 rpm from target idle speed, the ECU will adjust the ISC valve position to bring idle speed back on target.

FEEDBACK IDLE SPEED CONTROL

—v.

\

A-»B: After Start Control

B Warm-up Control

B

Load

Control

I ^ No Load

| Control

Coolant Temperature °F

Coolant Temperature °F

Do It Yourself Car Diagnosis

Do It Yourself Car Diagnosis

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