GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Buick 🢒 2003 🢒 Park Avenue 🢒 HVAC 🢒 HVAC Systems - Automatic 🢒 Temperature Variation Between Driver and Passenger Outlets

Step

Action

Value(s)

Yes

No

Schematic Reference: HVAC Schematics

Connector End View Reference: HVAC Connector End Views

DEFINITION: Temperature variation between driver and passenger A/C or heater outlets.

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

2

Important:: In order to execute the HVAC Recalibration command, the scan tool disrupts keep alive memory (KAM) causing DTC B1652 (Loss of KAM) to be set as history.

  1. Install a scan tool.
  2. Turn ON the ignition, with the engine OFF.
  3. With a scan tool, perform the HVAC Recalibration command in Heating and Air Conditioning Special Functions.
  4. With a scan tool, observe the current and history DTC list in Heating and Air Conditioning.

Does the scan tool display DTC B1340, B1341, B1343, or B1344?

--

Go to Diagnostic Trouble Code (DTC) List

Go to Step 3

3

Did the customer concern occur during A/C mode operation?

--

Go to Step 4

Go to Step 10

4

Important:: Ambient air temperature must be above 5°C (41°F).

  1. Cover the right and left sunload sensors.
  2. Start the engine.
  3. Fully open all panel outlets.
  4. Place the temperature switch in the coldest position.
  5. Place the mode switch in the vent position.
  6. Place the blower motor switch in the maximum speed position.
  7. Place the right air temperature switch assembly in the neutral position.
  8. Ensure that the recirculation indicator is not illuminated.

Are the right and left center panel outlet temperatures similar?

--

System OK

Go to Step 5

5

Perform the A/C 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?

--

Go to Step 23

Go to Step 6

6

Inspect the air temperature sensors for proper installation. Refer to the following procedures:

Did you find and correct the condition?

--

Go to Step 23

Go to Step 7

7
  1. Cover the right and left sunload sensors.
  2. Start the engine.
  3. Place the temperature switch in the 24°C (75°F) position.
  4. Place the right air temperature switch in the neutral position.
  5. With a scan tool, observe the Right and Left Solar Sensor data parameters in the Heating and Air Conditioning Open/Short data list.

Does the scan tool indicate that the Right and Left Solar Sensor data parameters are more than the specified value?

230  Counts

Go to Step 8

Go to Step 18

8
  1. Uncover the right and left sunload sensors.
  2. Direct the J 42220 Leak Detection Lamp at the right and then the left sunload sensors.

Do the counts change similarly and correspond to the proper sunload sensor?

--

Go to Step 9

Go to Step 18

9
  1. Install a thermometer near each of the four air temperature sensors.
    2. • The upper right temperature sensor
    • The upper left temperature sensor
    • The lower right temperature sensor
    • The lower left temperature sensor
  2. With a scan tool, observe the Driver AC Duct Temp and Passenger AC Duct Temp data parameters in the Heating and Air Conditioning HVAC Sensor data list.

Does the scan tool indicate that the sensor temperatures vary from the thermometer temperatures by less than the specified value?

3°C

(5°F)

System OK

Go to Step 16

10

Inspect the cooling system for the following conditions:

    • A low coolant level
    • A loose or worn accessory drive belt
    • A leaking radiator hose or heater hose
    • A kinked radiator hose or heater hose
    • A missing radiator cap pressure seal
    • A leaking radiator cap

Did you find and correct the condition?

--

Go to Step 23

Go to Step 11

11
  1. Cover the right and left sunload sensors.
  2. Start the engine.
  3. Fully open all panel outlets.
  4. Place the temperature switch in the warmest position.
  5. Place the mode switch in the floor (lower) position.
  6. Place the blower motor switch in the maximum speed position.
  7. Place the right air temperature switch assembly in the neutral position.

Are the right and left outlet temperatures similar?

--

System OK

Go to Step 12

12

Check the upper right, upper left, lower right, and lower left air temperature sensors for proper installation. Refer to the following procedures:

Did you find and correct the condition?

--

Go to Step 23

Go to Step 13

13
  1. Ensure the right and left sunload sensors are covered.
  2. Start the engine.
  3. Place the temperature switch in the 24°C (75°F) position.
  4. Place the right air temperature switch in the neutral position.
  5. With a scan tool, observe the Right and Left Solar Sensor data parameters in the Heating and Air Conditioning Open/Short data list.

Does the scan tool indicate that the Right and Left Solar Sensor data parameters are more than the specified value?

230  Counts

Go to Step 14

Go to Step 18

14
  1. Uncover the right and left sunload sensors.
  2. Direct the J 42220 at the right and then the left sunload sensors.

Do the counts change similarly and correspond to the proper sunload sensor?

--

Go to Step 15

Go to Step 18

15
  1. Install a thermometer near each of the four air temperature sensors.
    2. • The upper right temperature sensor
    • The upper left temperature sensor
    • The lower right temperature sensor
    • The lower left temperature sensor
  2. With a scan tool, observe the Driver AC Duct Temp, Driver Htr. Duct Temp, Passenger AC Duct Temp and Passenger Htr. Duct Temp data parameters in the Heating and Air Conditioning HVAC Sensor data list.

Does the scan tool indicate that the sensor temperatures vary from the thermometer temperatures by less than the specified value?

3°C

(5°F)

System OK

Go to Step 16

16

Inspect for poor connections at the harness connector of the suspect temperature 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 23

Go to Step 17

17

Test the suspect temperature sensor resistance. Refer to Sensor Resistance Table .

Is the resistance measurement near the value in the Sensor Resistance Table?

--

Go to Step 19

Go to Step 21

18

Inspect for poor connections at the harness connector of the suspect 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 23

Go to Step 20

19

Inspect for poor connections at the harness connectors of the instrument panel integration module (IPM). 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 23

Go to Step 22

20

Replace the suspect sunload sensor. Refer to Sun Load Sensor Replacement - Left Side or Sun Load Sensor Replacement - Right Side .

Did you complete the replacement?

--

Go to Step 23

--

21

Replace the temperature sensor. Refer to the following procedures:

Did you complete the replacement?

--

Go to Step 23

--

22

Important:: Perform the recalibration procedure for the replacement IPM.

Replace the IPM. Refer to Instrument Panel Module Replacement in Body Control System.

Did you complete the replacement?

--

Go to Step 23

--

23

Operate the system in order to verify the repair.

Did you correct the condition?

--

System OK

Go to Step 2