The electronic climate control (ECC) module serves as an
interface between the passenger and the air delivery system. The ECC module
compares passenger selections with environmental conditions and will adjust
air delivery accordingly.
Available air delivery modes:
| • | External air circulation |
| • | Internal air circulation |
The ECC module requires two voltage sources to operate. Voltage is available
in the following modes:
| • | With ignition switch in RUN: |
| - | Ignition switch (RUN position) |
A path to ground for the ECC module is provided by CKT 1850 (BLK)
to grounds G203/G204.
The ECC module receives inputs from the following temperature sensors:
| • | Inside air temperature sensor and CKT 734 (DK GRN). |
| | A fan located internally to the inside air temperature sensor housing
continually draws passenger compartment air over the sensor increasing accuracy
of the temperature reading. The HVAC fuse applies voltage to CKT 341
(BRN) for the fan motor when the ignition switch is in the RUN position.
A path to ground for the fan motor is provided by CKT 1850 (BLK) to
ground G202. |
| • | Ambient air temperature sensor and CKT 636 (DK GRN/WHT) |
| • | Sun load temperature sensor and CKT 590 (LT BLU/BLK) |
| • | Duct air temperature sensor and CKT 404 (BRN) |
| • | Duct air temperature sensor and CKT 405 (LT GRN) |
CKT 552 (BLK) provides the common ground path for the sensors
back to the ECC module.
The ECC module will use the sensor information to determine how much
airflow to the heater core is required and will adjust the air temperature
valve accordingly. The air temperature valve is located internally to the
heater core housing. The position of the air temperature valve is reported
to the ECC module by the air temperature valve sensor and motor. The HVAC
fuse applies voltage to CKT 341 (BRN) for the air temperature valve
sensor and motor when the ignition switch is in the RUN position.
Operation of the air temperature valve sensor and motor is supported
by the following circuits:
| • | CKT 1688 (LT BLU/BLK) for the 5 volt reference |
| • | CKT 1791 (YEL) for the ground reference |
| • | CKT 733 (LT BLU) for the signal return path |
| • | CKT 1199 (DK BLU) for the motor drive signal |
The ECC module will control the actuation of individual solenoids of
the HVAC solenoid assembly to direct air to the appropriate outlets. The HVAC
fuse applies voltage to CKT 341 (BRN) for the HVAC solenoid assembly
when the ignition switch is in the RUN position. With voltage available the
ECC module will complete the current path to ground.
The ECC module control of the HVAC solenoid assembly is supported by
the following circuits:
