When the engine is started, the ECU opens the ISCV to a pre-programmed position based on coolant temperature and sensed rpm. The higher the commanded rpm, the longer the duty ratio will be. As the engine approaches normal operating temperature, engine speed is gradually reduced.
Once the engine is fully warmed up, the ECU utilizes a feedback idle speed control strategy which functions identically with the stepper motor ISC system. Different target idle speeds are established depending on the status of load sensor inputs.
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