1. Turn ON the ignition.
2. Observe the temperature indication screen of the controller.

Does the digit flash?

Go to Step 2

Go to Step 3

Run a self diagnosis circuit check.

Does the display indicate a defect code?

Go to the specific DTC table

Go to Step 7

Observe the blower motor operation.

Is the blower motor functioning properly?

Go to Step 4

Go to Blower Motor Inoperative

Use the blower push switch to cycle the blower through its different speeds.

Does the motor function at different speeds?

Go to Step 5

Go to DTC 6

1. Run the blower and operate the MODE push switch manually.
2. Inspect for airflow out the various outlets.

Does the air flow from the different outlets as it should?

Go to Step 7

Go to Step 6

1. Remove the heater outlet and check for obstructions.
2. Remove any obstructions found.

Is the heater operating?

System OK

Go to Step 9

Observe the air mix door motor while changing the temperature setting from LO to HI and then from HI to LO.

Is the air mix door actuator functioning properly?

Go to Step 8

Go to DTC 4

Perform the checks found in HVAC Preliminary Checks .

Is the system operating normally now?

System OK

Go to Step 9

Place the controller in the AUTO mode.

Is smoke taken into the intake port of the in-car sensor?

Go to Step 12

Go to Step 10

Inspect the intake hose for the in-car sensor.

Is the hose in good condition?

Go to Step 12

Go to Step 11

Repair or replace the intake hose.

Did you complete the repair?

System OK

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Inspect the in-car sensor using the test in DTC 1.

Is there a problem indicated in the sensor, the sensor wiring, or the controller?

Go to Step 13

Go to Step 14

Repair or replace the sensor, the wiring , or the controller as required.

Did you complete the repair?

System OK

--

Inspect the ambient air temperature sensor using the test in DTC 2.

Is there a problem indicated in the sensor, the sensor wiring, or the controller?

Go to Step 15

Go to Step 16

Repair or replace the sensor, the wiring, or the controller as required.

Did you complete the repair?

System OK

--

Inspect the sun sensor using the test in DTC 5.

Is there a problem indicated in the sensor, the sensor wiring or the controller?

Go to Step 17

Go to Step 18

Repair or replace the sensor, the wiring, or the controller as required.

Did you complete the repair?

System OK

--

Perform the coolant temperature sensor test.

Is the coolant temperature sensor functioning properly?

Go to Step 19

Go to Step 20

Replace the coolant temperature sensor.

Did you complete the repair?

System OK

--

Replace the full automatic temperature control (FATC) controller.

Did you complete the repair?

System OK

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