Schematic Reference: HVAC Schematics

DEFINITION: The temperature cannot be adjusted, or cooling is insufficient during A/C operation.

1

Did you perform the HVAC Diagnostic System Check?

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Go to Step 2

Go to Diagnostic System Check - HVAC Systems - Manual

Important: Both left (driver) and right (passenger) air temperature control concerns are diagnosed in this table.

1. Turn ON the ignition, with the engine OFF.
2. Place the blower motor switch in each speed position.

Does the blower motor operate in any of the speed positions?

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Go to Step 3

Go to Blower Motor Inoperative

Does the blower motor operate in the desired speed(s)?

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Go to Step 4

Go to Blower Motor Malfunction

1. Start the engine.
2. Place the blower motor switch in the maximum speed position.
3. Place the mode switch in the MAX position.

Does the recirculation door move to the recirculation position?

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Go to Step 5

Go to Vacuum Control System Diagnostic

When the A/C is ON, does the customer concern occur?

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Go to Step 6

Go to Step 8

IMPORTANT:: Ambient air temperature must be above 3°C (38°F).

1. Start the engine.
2. Place the blower motor switch in the maximum speed position.
3. Place the mode switch in the VENT position.
4. Place the A/C request switch in the ON position.
5. Place the left and right temperature switches in the coldest position.

Does the A/C compressor operate?

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Go to Step 7

Go to HVAC Compressor Clutch Does Not Engage

Perform the refrigerant system performance test. Refer to Air Conditioning (A/C) System Performance Test in Heating Ventilation and Air Conditioning.

Did you find and correct the condition?

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Go to Step 19

Go to Step  8

1. Observe the drive shaft of the left and right air temperature actuator.
2. Place the air temperature switches from the coldest position to the warmest position.

Do the left and right air temperature actuator drive shafts rotate?

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Go to Step 9

Go to Step 10

Inspect the air temperature doors and the air temperature actuators for the following conditions:

Did you find and correct the condition?

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Go to Step 19

Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems

Test the ignition 3 voltage circuit of the suspect air temperature actuator for an open or a high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

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Go to Step 19

Go to Step 11

Test the ground circuit of the suspect air temperature actuator for an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

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Go to Step 19

Go to Step 12

Test the air temperature door control circuit of the suspect air temperature actuator for an open, high resistance, short to ground, or short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

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Go to Step 19

Go to Step 13

13

Important: The HVAC control module connector must be connected to correctly perform this test.

1. Turn ON the ignition, with the engine OFF.
2. Measure the voltage from the suspect air temperature door control circuit of the air temperature actuator to a good ground.
3. Place the air temperature switch from the coldest position to the warmest position.

Does the voltage measure within the specified values with a smooth transition between cold and hot?

0-12 V

Go to Step 14

Go to Step 16

Inspect for poor connections at the harness connector of the air temperature actuator. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

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Go to Step 19

Go to Step 15

Inspect the air temperature actuator, door and any attaching linkage for binding or a condition that prevents drive shaft rotation.

Did you find and correct the condition?

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Go to Step 19

Go to Step  17

Inspect for poor connections at the harness connector of the HVAC control module. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

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Go to Step 19

Go to Step 18

Replace the suspect air temperature actuator. Refer to Air Temperature Actuator Replacement - Right Side or Air Temperature Actuator Replacement - Left Side .

Did you complete the replacement?

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Go to Step 19

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Replace the HVAC control module. Refer to HVAC Control Module Replacement .

Did you complete the replacement?

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Go to Step 19

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Operate the system in order to verify the repair.

Did you correct the condition?

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System OK

Go to Step 2