Schematic Reference: HVAC Schematics

DEFINITION: The temperature cannot be adjusted or the heating is insufficient.

1

Did you perform the HVAC Diagnostic System Check?

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Go to Step 2

Go to Diagnostic System Check - HVAC Systems - Automatic

1. Disconnect the scan tool.
2. Turn OFF the ignition.
3. Remove the RADIO-HVAC fuse to interrupt the keep alive memory of the HVAC Control Module.
4. Install the RADIO-HVAC fuse.
5. Install a scan tool.
6. Turn ON the ignition, with the engine OFF.
7. Observe the Diagnostic Trouble Code (DTC) List in Body, Heating, and Air Conditioning.

Does the scan tool display any DTC B0361, B0363, B0365, B0367, B0441 or B0446?

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Go to Diagnostic Trouble Code (DTC) List

Go to Step 3

3

Important:: The ambient air temperature must be above 3°C (38°F).

1. Start the engine.
2. Place the HVAC control module in OFF position.

Does the A/C compressor operate?

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Go to Step 4

Go to HVAC Compressor Clutch Does Not Disengage

Place the blower motor switch in each speed position.

Does the blower motor operate in each speed position?

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Go to Step 5

Go to Blower Motor Inoperative

Does the blower motor provide sufficient air flow?

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Go to Step 6

Go to Blower Motor Malfunction

1. Start the engine.
2. Place the mode switch in the vent position.
3. Place the blower motor switch in the maximum speed position.
4. Place the outside air switch in the ON position.
5. Place the recirculation switch in the ON position.

Does the recirculation door operate properly?

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Go to Step 7

Go to Air Recirculation Malfunction

7

Inspect the cooling system for the following conditions:

Refer to Heating Performance Diagnostic in Heating, Ventilation and Air Conditioning.

Did you find and correct the condition?

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Go to Step 20

Go to Step 8

1. Install a thermometer near the inside air temperature sensor and record the air temperature.
2. With a scan tool, record the values of the Inside Air Temp data parameters in the Body, Heating and Air Conditioning Data list. Refer to Sensor Resistance Table .

Does the scan tool indicate that the inside air temperature sensor is near the specified value for the recorded air temperature?

-5 to +5°C

(-5 to +5°F)

Go to Step 10

Go to Step 9

Inspect for a blocked, malfunctioning, or incorrectly installed inside air temperature sensor. Refer to Inside Air Temperature Sensor Replacement .

Did you find and correct the condition?

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Go to Step 20

Go to Step 13

1. Turn the engine OFF.
2. Install a scan tool.
3. Cover the sunload sensor.
4. Start the engine.
5. Set the passenger side temperature to the 12 o'clock or neutral position.
6. Adjust driver side temperature to 22°C (72°F).
7. With a scan tool, observe the Sunload Sensor data parameter in the Body, Heating, and Air Conditioning data list.

Does the scan tool indicate that the Sunload Sensor parameter is greater than the specified value?

230 Counts

Go to Step 11

Go to Step 15

1. Uncover the sunload sensor.
2. Direct a light source at the sunload sensor.

Does the voltage change?

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Go to Step 12

Go to Step 15

Does the customer need to change the set temperature frequently to maintain comfort?

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Go to Symptoms - HVAC Systems - Automatic

System OK

Inspect for poor connections at the harness connector of the inside air temperature sensor. 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 20

Go to Step 14

1. Turn OFF the ignition.
2. Test the inside air temperature sensor resistance. Refer to Sensor Resistance Table .

Does the resistance measure near the specified value?

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Go to Step 16

Go to Step 17

Inspect for poor connections at the harness connector of the sunload sensor. 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 20

Go to Step 18

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 20

Go to Step 19

Replace the inside air temperature sensor. Refer to Inside Air Temperature Sensor Replacement .

Did you complete the replacement?

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Go to Step 20

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Replace the sunload sensor. Refer to Sun Load Sensor Replacement .

Did you complete the replacement?

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Go to Step 20

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Important:: Perform the recalibration procedure for the HVAC control module.

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

Did you complete the replacement?

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Go to Step 20

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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 3