Initial Inspection and Diagnostic Overview

Operational Check
The purpose of the operational check is to confirm that the system operates properly.

Conditions: Engine running and at usual operating temperature

CHECKING MEMORY FUNCTION
1. Set the temperature to 32 °C (90 °F).
2. Press the OFF switch.
3. Turn ignition switch OFF.
4. Start engine.
5. Press the AUTO switch.
6. Confirm that the set temperature remains at previous temperature.
7. Press the OFF switch.

If NG, go to trouble diagnosis procedure for ATC-77, "Memory Function". Memory Function Does Not Operate
If OK, continue with next check.

CHECKING BLOWER
1. Press top of blower control switch. Blower should operate on low speed. The fan symbol should have one blade lit.
2. Press top of blower control switch again, and continue checking blower speed and fan symbol until all speeds are checked.
3. Leave blower on maximum speed.

If NG, go to trouble diagnosis procedure for ATC-55, "Blower Motor Circuit". Blower Motor Circuit
If OK, continue with next check.




CHECKING DISCHARGE AIR
If NG, go to trouble diagnosis procedure for ATC-47, "Mode Door Motor Circuit". Mode Door Motor Circuit
If OK, continue with next check.




CHECKING RECIRCULATION
If NG, go to trouble diagnosis procedure for ATC-53, "Intake Door Motor Circuit". Intake Door Motor Circuit
If OK, continue with next check.

CHECKING TEMPERATURE DECREASE
1. Rotate temperature control dial counterclockwise (driver) until 16 °C (60 °F) is displayed.
2. Check for cold air at discharge air outlets.

If NG, go to trouble diagnosis procedure for ATC-65, "Insufficient Cooling". Insufficient Cooling
If OK, continue with next check.

CHECKING TEMPERATURE INCREASE
1. Rotate temperature control dial clockwise (driver) until 32 °C (90 °F) is displayed.
2. Check for hot air at discharge air outlets.

If NG, go to trouble diagnosis procedure for ATC-73, "Insufficient Heating". Insufficient Heating
If OK, continue with next check.

CHECKING TEMPERATURE DECREASE
1. Press the DUAL switch (indicator ON).
2. Rotate temperature control dial counterclockwise (passenger) until 16 °C (60 °F) is displayed.
3. Check for cold air at passenger discharge air outlets.

If NG, go to trouble diagnosis procedure for ATC-65, "Insufficient Cooling". Insufficient Cooling
If OK, continue with next check.

CHECKING TEMPERATURE INCREASE
1. Rotate temperature control dial clockwise (passenger) until 32 °C (90 °F) is displayed.
2. Check for hot air at passenger discharge air outlets.

If NG, go to trouble diagnosis procedure for ATC-73, "Insufficient Heating". Insufficient Heating
If OK, continue with next check.

CHECK A/C SWITCH
1. Press the OFF switch.
2. Press the top of the fan switch. the fan should operate.
3. Press A/C switch.
4. A/C switch indicator will turn ON.
- Confirm that the compressor clutch engages (sound or visual inspection).

If NG, go to trouble diagnosis procedure for ATC-61, "Magnet Clutch Circuit". Magnet Clutch Circuit
If OK, continue with next check.

CHECK NAVI DISPLAY OR A/C DISPLAY
1. Turn ignition switch ON.
2. Press each switch on the front air control and monitor the HVAC display.
- Confirm that the HVAC display operates correctly for each switch pressed.

If NG, go to trouble diagnosis procedure for NAVI, refer to AV-133,"On Board Self-Diagnosis Function". Terminal and Reference Value For Display Unit For A/ C display refer to ATC-89, "A/C Display (without NAVI)". A/C Display (Without NAVI)
If OK, continue with next check.

CHECKING AUTO MODE
1. Press the OFF switch.
2. Press AUTO switch.
3. Display should indicate AUTO.
- Confirm that the compressor clutch engages (sound or visual inspection). (Discharge air and blower speed will depend on ambient, in-vehicle, and set temperatures.)

If NG, go to trouble diagnosis procedure for ATC-42, "Power Supply and Ground Circuit for Front Air Control and Unified Meter and A/C Amp", Power Supply and Ground Circuit For Front Air Control and Unified Meter and A/C Ampthen if necessary, trouble diagnosis procedure for ATC-61, "Magnet Clutch Circuit". Magnet Clutch Circuit
If all operational checks are OK (symptom cannot be duplicated), go to malfunction Simulation Tests in ATC- 25, "How to Perform Trouble Diagnosis for Quick and Accurate Repair" Symptom Chart and perform tests as outlined to simulate driving conditions environment. If symptom appears, refer to, ATC-25, "How to Perform Trouble Diagnosis for Quick and Accurate Repair" Symptom Chart and perform applicable trouble diagnosis procedures.