The electronic climate control (ECC) module may access
3 additional purge modes when the following conditions exist:
| • | When the system is powered up, purge the system of stale air and/or
redirect the air in order to avoid window fogging or other undesirable conditions. |
| • | When the ignition is turned ON and the fan increase/decrease knob
is not in the OFF position, the ECC module will determine if any of the undesirable
conditions exist. |
The ECC module may select from one of the following 3 purge modes in
order to eliminate the undesirable condition:
Normal Purge Mode
Moisture tends to accumulate in the heater and the A/C module assembly
after the engine has been turned off. When the engine is restarted and the
A/C system turns ON this moisture may be expelled from the windshield or
panel outlets and cause window fogging. The normal purge mode is bypassed
if the fan is in a manual selection.
Cold Purge Mode
In the cold weather, the moist breath air from the vehicle occupants
may condense on the windshield. On cold startup, the ECC module checks for
indications that this condition may occur. If this condition occurs, the
ECC module performs the following actions:
| • | Positions the doors in order to direct air out of the windshield
outlets |
The ECC module then resumes normal system operation.
A/C Purge Mode
Moisture tends to accumulate in the ECC module assembly after the engine
has been turned off. When the engine is restarted and the A/C system turns
ON, this moisture may be expelled from the panel outlets toward the front
seat occupants.
During startup, the heater and ECC module inspects for indications that
this condition may occur. If this condition occurs, the ECC module performs
the following actions:
| • | Positions the A/C door in order to direct air toward the floor |
The ECC module then resumes normal system operation.
