1. Disconnect the in-car sensor connector from the automatic temperature controller (ATC).
2. Examine the wiring from the sensor to the connector and the connector for any signs of damage.
3. Measure the resistance between the in-car sensor connector terminals.

Is there any sign of damage in the wiring or connector, or is the resistance outside the specified value at 20-25°C (68-77°F)?

2,100-2,600 ohms

Go to Step 2

Go to Step 3

Repair the damaged wiring or the connector, or replace the in-car sensor as required.

Is the repair complete?

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System OK

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1. Turn ON the ignition, with the engine OFF.
2. Measure the voltage between the 2 connector terminals on the controller housing.

Does the voltage measure greater than the specified value?

4 V

Go to Step 7

Go to Step 4

Inspect the terminals on the in-car sensor connector.

Is any problem found with the connector?

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Go to Step 5

Go to Step 6

Repair the connector terminals or replace the in-car sensor or ATC as required.

Is the repair complete?

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System OK

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1. Reconnect the in-car sensor to the controller.
2. Turn ON the ignition, with the engine OFF.
3. Observe the temperature display area.

Does this display indicate the continuing presence of a code 1 condition?

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Go to Step 7

System OK

Replace the ATC controller. Refer to Heater and Air Conditioning Control Replacement .

Is the repair complete?

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System OK

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