Coolant Temperature Switch

PURPOSE
The enrichment coolant temperature switch operates in conjunction with the WOT vacuum switch (warm) to cause the mixture control solenoid to provide the rich air/fuel mixture necessary for the increased airflow during warm engine wide open throttle operation. This switch closes when the engine coolant temperature reaches 135° F.

The open loop coolant temperature switch is open during engine warm-up below 95° F. This results in the MCU not accepting the oxygen sensor voltage output and predetermined air/ fuel mixture is maintained (open loop mode of operation).


NOTE: The enrichment coolant temperature switch and open loop coolant temperature switch are not contained in one unit.