Engine - Coolant Temperature Sensor/Switch: Description and Operation

Coolant Temperature Sensor (B11/9 And B11/10) Location:

PURPOSE AND LOCATION
The two coolant temperature sensors (B11/9 and B11/10) which are located at front center of engine, measures engine coolant temperature. The information provided by the coolant temperature sensors is used by the LH control modules (N3/2 and N3/3) to calculate air/fuel mixture and idle speed correction. The same information is also used by the EZL/AKR control modules via the controller area network (CAN).

Fig. 39 Coolant Temperature Sensor:

OPERATION
Actually there are two independent temperature sensors combined in one housing. Both sensors are the negative temperature coefficient (NTC) type (resistance decreases as coolant temperature increases). The sensor has two ground connections, engine ground and LH control module ground.
Since both circuits of the sensor have the same resistance curves, the sensor connector can be installed in either orientation without affecting the operation of the circuit.