Chart 4 Improper Air Delivery

Air Delivery Schematic:

Chart 4, Improper Air Delivery:

CIRCUIT DESCRIPTION
The Electronic Climate Control (ECC) programmer directs the blended air in one of several air delivery modes as instructed by the Body Control Module (BCM). While the side window outlets receive air flow during all modes of operation, the other outlets are directed air by the ECC programmer energizing specific vacuum valves feeding the appropriate combination of mode valve actuators. The ECC programmer determines the proper air delivery mode based upon the current program number, control panel setting, set temperature, low side temperature, coolant temperature, outside air temperature and sun load.

1. This step checks the vacuum supply to programmer
2. Checks the heater part of the heater A/C Bi-level Valve (door).
3. Checks the A/C part of the heater-A/C Bi-level Valve (door) and the defrost side of the A/C.defrost valve (door).
4. Checks the A/C side of the A/C-defrost valve (door).
5. Checks the vacuum hoses for restrictions and valves for binding.