1. Disconnect the ambient air sensor connector from the front bumper harness.
2. Measure the resistance between the ambient air sensor connector terminals.

Is the resistance equal to the specified value at 20-25°C (68-77°F)?

2,100-2,600 ohms

Go to Step 5

Go to Step 2

1. Remove the ambient air sensor from behind the front bumper.
2. Examine the wiring for any open or short and examine the connector for any damage.

Is there a problem with the wiring or the connector?

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Go to Step 3

Go to Step 4

Repair the problem found in the ambient air sensor wiring or the connector.

Is the repair complete?

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System OK

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Replace the ambient air sensor. Refer to Ambient Air Temperature Sensor Replacement .

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 terminals in the ambient air sensor connector on the front bumper harness.

Does the voltage measure greater than the specified value?

4 V

Go to Step 7

Go to Step 6

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 2 condition?

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Go to Step 8

System OK

1. Pull the automatic temperature controller (ATC) from the instrument panel, leaving the wiring harness connected.
2. Measure the voltage between terminals A13 and B8 by backprobing the connectors.

Does the voltage measure less than the specified value?

4 V

Go to Step 8

Go to Step 9

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

Is the repair complete?

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System OK

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1. Trace the wiring for the ambient air sensor from the ATC, through connectors C217, C210, C103, and C101 at the engine fuse block, and C108 to the ambient air sensor connector on the front bumper harness.
2. Repair any open or high resistance condition in the wiring or a connector terminal.

Is the repair complete?

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System OK

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