Coolant Temperature Sensor
Sensor provides ECU with engine temperature information relating to warm-up enrichment operation. During warm-up from cold start, additional fuel is required to maintain engine performance. As engine temperature increases, the ECU decreases fuel enrichment until engine reaches normal operating temperature. Models not equipped with a coolant temperature sensor utilize a cylinder head temperature sensor instead. This functions in the same manner. Input is used to control air/fuel mixture, timing and idle speed.