Coolant Temperature Sensor

This sensor is located in the thermostat housing or intake manifold runner. By monitoring engine temperature it signals the SMEC when to operate the air switching in the EGR and Spark Advance systems. Resistance across coolant temperature sensor terminals should read 7000-13,000 ohms at 70°F (21°C) or 700-1000 ohms at 200°F (70°C).