1. Turn OFF the ignition.
2. Disconnect the automatic temperature control (FATC) controller connector.
3. Disconnect the power transistor connector.
4. Measure the resistance between terminal 4 of the power transistor and terminal B20 of the FATC controller.

Does the resistance equal the specified value?

0 ohms

Go to Step 2

Go to Step 6

Measure the resistance between terminal 1 of the power transistor and terminal B9 of the FATC controller.

Does the resistance measure equal tothe specified value?

0 ohms

Go to Step 3

Go to Step 6

1. Connect the power transistor connector and the FATC connectors.
2. Turn ON the ignition.
3. Measure the voltage between ground and terminal B9 of the FATC controller while changing the blower speed from 1 to 5 manually.

Do the voltages measured match approximately the specified values within ±0.5 V?

1: 8.8 V

2: 6.8 V

3: 4.8 V

4: 2.8 V

5: 0 V

Go to Step 4

Go to Step 5

Replace the FATC controller.

Did you complete the repair?

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System OK

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Measure the resistance between terminal 6 of the power transistor and terminal 1 of the blower motor.

Does the resistance measure equal to the specified value?

0 ohms

Go to Step 7

Go to Step 6

Repair or replace the wiring harness for the circuit (Violet).

Did you complete the repair?

--

System OK

--

Inspect the wiring harness of the motor and power supply.

Is there any problem in the wiring, the relay, or the fuse?

--

Go to Step 9

Go to Step 8

Replace the power transistor.

Did you complete the repair?

--

System OK

--

Repair or replace the wiring harness, the relay, or the fuse as required.

Did you complete the repair?

--

System OK

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