Charge Temperature Switch

This sensor is located in the intake manifold. The switch will be closed when intake charge (air/fuel mixture) is below 60°F. This permits no EGR timer function, no EGR valve operation and switches air injection upstream into exhaust system. When temperature is above 60°F, the switch opens, allowing EGR timer to time out, the EGR valve to operate and air injection is switched downstream into the exhaust system.