Evaporator Temperature Sensor: Operation: Notes

WARNING: This page is about a different car, the 2004 Dodge Dakota. However, it is still accessible from the selected car via links, so may be relevant.

The A/C-heater control will send a programmable communications interface (PCI) bus message to the powertrain control module (PCM), which will check engine, coolant temperature, and refrigerant pressure temperature before turning on the A/C compressor clutch. Turning the A/C compressor clutch on will allow the system to cool the A/C evaporator. The BCM will send a message to the PCM when the evaporator temperature becomes too cold. The PCM will then turn the A/C compressor clutch off, before evaporator freeze-up occurs. The DRBIII(R) scan tool can be used to monitor this operation. The temperature set point at which the clutch is turned off varies with the outside ambient temperature. The temperature at which the clutch is turned on is preset to 1°C (2°F) above the off setpoint mentioned above. Refer to ( Figure ) and the Evaporator Temperature Sensor Set Point table for the correct setpoint.