Description & Operation: Notes

Transmission Controlled Spark (TCS) system reduces the emission of oxides of nitrogen (NOx) by lowering peak combustion temperature. TCS system consists of a solenoid vacuum valve located at right rear of intake manifold (V8 engines) or on a bracket at rear of intake manifold (6-cylinder engines), a solenoid control switch located at the transmission, and a Coolant Temperature Override (CTO) switch located at the thermostat housing (V8 engines) or left rear side of block (6-cylinder engines).