Initial Inspection and Diagnostic Overview

Operational Check
The purpose of the operational check is to confirm that the system operates as it should. The systems which will be checked are the blower, mode (discharge air), ambient display, intake air, defrost, econ, auto, temperature decrease, temperature increase, and the memory function.

CONDITIONS:
Engine running at normal operating temperature.

PROCEDURE:





1. Check blower
1) Press FAN switch (Up) one time.
MANUAL should appear on the display.
Blower should operate on low speed, and the fan symbol should have one blade lit.
2) Press FAN switch one more time.
3) Continue checking blower speed and fan symbol until all four speeds have been checked.
4) Leave blower on high speed.
5) Press FAN switch (Down) onetime. Blower should operate in third speed.
6) Continue checking blower speed and fan symbol until all three speeds have been checked.





2. Check discharge air
1) Press the Face switch.
Display should show air to the face.
2) Confirm that all discharge air comes out the face vents.
3) Press Face and Foot switch.
Display should show air to face and foot (bi-level).
4) Confirm that discharge air comes out the face and foot vents.
5) Press the Foot switch.
Display should show air to foot.
6) Confirm that discharge air comes mostly from the foot outlets, with some air from the defroster outlets.
7) Press DEF and Foot switch.
Display should show air to foot and defrost.
8) Confirm that discharge air comes mostly from the defrost vents, with some air from the foot outlets.





3. Check ambient display
Press the AMB switch.
Display should show the outside (ambient) temperature for approximately 5 seconds.





4. Check recirc
1) Press RECIRC switch.
RECIRC indicator should light.
2) Listen for intake door position change (you should hear blower sound change slightly).





5. Check defrost
1) Press defrost switch.
2) Check that RECIRC is canceled.
The discharge air should be coming only from the defrost vents.
3) Confirm that the compressor clutch is engaged (visual inspection).
The display should indicate AUTO, MANUAL, and defrost.





6. Check ECON mode
1) Press ECON switch.
Defrost should be canceled.
Discharge air outlet will depend on ambient, in-vehicle, and set temperatures.
Display should indicate ECON (no AUTO, no MANUAL).
2) Confirm that the compressor clutch is not engaged (visual inspection).





7. Check AUTO mode
1) Press AUTO switch.
2) Confirm that the compressor clutch engages (audio or visual inspection).
Display should indicate AUTO (no ECON, no MANUAL).
(Discharge air will depend on ambient, in-vehicle, and set temperatures).





8. Check temperature decrease
1) Turn temperature switch counterclockwise until 18°C (65°F) is displayed.
2) Check for cold air at discharge air outlets.





9. Check temperature Increase
1) Turn temperature switch clockwise until 32°C (85°F) is displayed.
2) Listen for changes in blower speed as set temperature changes.
3) Check for hot air at discharge air outlets.





10. Check memory function
1) Press off switch.
2) Turn the ignition off.
3) Turn the ignition on.
4) Press the AUTO switch.
5) Confirm that the set temperature remained at 32°C (85°F).





11. Check rear window defogger
1) Press rear window defogger switch.
Rear window defogger indicator should turn on.