Air Temperature Sensor ( Ambient / Intake ): Description and Operation

Fig. 4 Switches & sensors location. V8 engine:

The CTS, Fig. 4, is used on eight cylinder engines only and is located in the No. 8 runner on eight cylinder engines. When the incoming air fuel mixture is below 60°F, the CTS will close, allowing no EGR timer function, no EGR valve operation and, on eight cylinder engines, air injection upstream on exhaust manifold. When incoming air fuel mixture is above 60°F, the CTS will open allowing EGR timer to expire, the EGR valve to operate and, on eight cylinder engines air injection switched downstream into the exhaust system.