Coolant Switch

The switch is located on the thermostat housing and supplies a signal to the computer when engine coolant temperature reaches a predetermined temperature.

This information is required to prevent air/fuel ratio from changing until engine reaches normal operating temperature. The computer also controls the amount of spark advance with a cold engine. See Fig 1 and Fig 2 .

Fig 1: Location of Coolant Switch (1.6L)

Fig 2: Location of Coolant Switch (2.2L)