Charge Temperature Switch
Used on 6 cyl. and V8 engines only. CTS switch is located in No. 6 branch runner of intake manifold on 6 cyl. engines and in No. 8 branch runner of intake manifold on V8 engines. When air/fuel mixture temperature is below 60°F, switch will be closed, preventing EGR timer and valve operation. When air/fuel mixture temperature is above 60°F, switch will open, allowing EGR timer and valve operation and on V8 engines, change air pump air injection from upstream to downstream in exhaust system.