1. Turn the ignition switch ON.
2. Set the blower speed manually for maximum speed.
3. Measure voltage between the automatic temperature control (ATC) controller terminal A10 and ground.

Is the voltage measured approximately equal to the specified value?

0 ohms

Go to Step 3

Go to Step 2

Replace the ATC controller.

Did you complete the replacement?

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System OK

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1. Inspect the wiring harness associated with the MAX-HI relay for defects or high terminal resistance.
2. Repair any defects found.

Did you find and correct the condition?

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System OK

Go to Step 4

Replace the MAX-HI relay.

Did you complete the replacement?

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System OK

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