GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Buick 🢒 2005 🢒 Rendezvous - FWD 🢒 Vehicle Control Systems 🢒 Vehicle DTC Information 🢒 Too Cold in Vehicle

Test Description

The step numbers below refer to the step numbers on the diagnostic table.

  1. This checks for A/C compressor clutch always ON.

    2.

  2. This test is to ensure the cooling system is operating normally.

    3.

  3. The aspirator tube connects to the rear of the HVAC control module. The aspirator tube is used to draw air past the inside air temperature sensor.

Step

Action

Values

Yes

No

Schematic Reference: HVAC Schematics

Connector End View Reference: HVAC Connector End Views

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

1

Did you perform Diagnostic System Check - Vehicle?

--

Go to Step 2

Go to Diagnostic System Check - Vehicle in Vehicle DTC Information

2
  1. Install a scan tool.
  2. Turn ON the ignition, with the engine OFF.
  3. Observe the DTC List.

Does the scan tool display any DTC B0165, B0166, B0408, B0418, or B0233?

--

Go to Diagnostic Trouble Code (DTC) List - Vehicle in Vehicle DTC Information

Go to Step 3

3

  1. Start the engine.
  2. Turn OFF the HVAC controls.

Does the A/C compressor operate?

--

Go to HVAC Compressor Clutch Does Not Disengage

Go to Step  4

4

Place the blower motor switch in each speed position.

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

--

Go to Step 5

Go to Blower Motor Inoperative

5

Does the blower motor operate in the desired speeds?

--

Go to Step 6

Go to Blower Motor Malfunction

6
  1. Place the blower motor switch in the maximum speed position.
  2. Place the mode switch in the vent position.
  3. Place the recirculation switch in the ON and OFF positions.

Does the recirculation door operate properly?

--

Go to Step 7

Go to Air Recirculation Malfunction

7

Perform the heater performance diagnostic. Refer to Heating Performance Diagnostic in Heating, Ventilation and Air Conditioning.

Did you find and correct the condition?

--

Go to Step 21

Go to Step 8

8
  1. Turn ON the ignition, with engine OFF.
  2. With a scan tool, command the right and left air temperature actuators Hot and Cold.
  3. Observe the Right Temp Door Position and the Left Temp Door Position parameters.

Do the counts change when the actuators are commanded?

--

Go to Step 9

Go to Step 13

9
  1. Install a thermometer near the inside air temperature sensor.
  2. With a scan tool, observe the Inside Air Temp data parameters in the Heating and Air Conditioning Data list.

Does the scan tool indicate the sensor temperature are within 3°C (5°F) of the thermometer temperatures?

--

Go to Step 11

Go to Step 10

10

Inspect for a blocked aspirator tube of the HVAC control module.

Did you find and correct the condition?

--

Go to Step 21

Go to Step 17

11
  1. Turn the engine OFF.
  2. Install a scan tool.
  3. Cover the sunload sensor.
  4. Start the engine.
  5. Adjust the driver side temperature to 22°C (72°F).
  6. With a scan tool, observe the Sunload Sensor data parameter in the Heating and Air Condition data list.

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

230 Counts

Go to Step 12

Go to Step 16

12

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

Does the voltage change?

--

System OK

Go to Step 16

13

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

Did you find and correct the condition?

--

Go to Step 21

Go to Step 14

14

Test the suspect actuator ignition 3 voltage circuit for a short to ground, an open, or high resistance. Refer to Circuit Testing and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 21

Go to Step 15

15

Inspect for poor connections at the harness connector of the suspect 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?

--

Go to Step 21

Go to Step 19

16

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?

--

Go to Step 21

Go to Step 18

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?

--

Go to Step 21

Go to Step 20

18

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

Did you complete the replacement?

--

Go to Step 21

--

19

Important: Perform the recalibration procedure for the air temperature actuator

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?

--

Go to Step 21

--

20

Replace the HVAC control module. Refer to Control Module References in Computer/Integrating Systems.

Did you complete the replacement?

--

Go to Step 21

--

21

Operate the system in order to verify the repair.

Did you correct the condition?

--

System OK

Go to Step 3