Temperature Sensing

IHKR1 TEMPERATURE SENSING

The IHKR1 system uses five Negative Temperature Coefficient (NTC) temperature sensors. As temperature increases, sensor resistance decreases; as temperature decreases, resistance increases.







AMBIENT TEMPERATURE SENSOR: The ambient temperature sensor is mounted on the housing assembly, at the right fresh air flap. It is the only sensor that does not have a connector. To replace the sensor, its wires must be cut and a new sensor spliced to the wiring harness.







EVAPORATOR TEMPERATURE SENSOR: The evaporator temperature sensor slides into a small hole at the lower left side of the housing assembly (just to the right of the accelerator pedal). It fits inside the evaporator core, and is used to keep the evaporator temperature at about 35 °F.







INTERIOR TEMPERATURE SENSOR: The interior temperature sensor is mounted inside the control panel, behind a protective grille. The interior temperature sensor is very important since the control module calculates the "Y" factor largely from this sensor's input and the left/right desired temperature knob settings.







HEATER CORE TEMPERATURE SENSOR (2): A heater core temperature sensor is located just behind each heater core, where it is exposed to air that has just passed through the core. The left and right heater core temperature sensors are identical and interchangeable.

All of these temperature sensors can be checked using the DIS unit by selecting the "temperature sensors" option from the Diagnosis "Status Requests" screen. Remember that, as of the current DIS software release, temperature values are shown in Celsius units only.