Engine Coolant Temperature Sensor, Turbo

Fig. 28 Coolant Temperature Sensor:

Fig. 29 Coolant Temperature Sensor Resistance Graph:

Fig. 19 Coolant Temperature Sensor Location:

The coolant temperature sensor, Fig. 28, is a negative temperature coefficient resistor (NTC). As the temperature increases, the resistance decreases, Fig. 29. The sensor is located in the cylinder head, next to the #1 spark plug, Fig. 19. The resistance signal is used by the control unit to advance the ignition timing when the engine is cold, and manifold pressure is below 1.0 bar (0 in Hg). The sensor is also used to correct the fuel mixture at various temperatures.