GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Buick 🢒 2000 🢒 Regal (China) 🢒 HVAC 🢒 HVAC Systems - Automatic 🢒 Air Recirculation Malfunction

Test Description

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

  1. Listen for an audible click or feel for the click when the vacuum control assembly operates. Repeat the test as necessary.

    2.

  2. Tests for voltage on circuit 41 at the vacuum control assembly.

    3.

  3. Verifies that the HVAC control module is providing ground to the vacuum control assembly.

    4.

  4. Tests if ground is constantly being applied to the vacuum control assembly.

Step

Action

Values

Yes

No

Schematic Reference: HVAC Air Delivery/Temperature Control Schematics

DEFINITION: Air recirculation is inoperative or is always ON.

1

Did you perform the HVAC Diagnostic System Check?

--

Go to Step 2

Go to Diagnostic System Check

2
  1. Install a scan tool.
  2. With a scan tool, observe the Recirculate Button parameter in the Heating and Air Conditioning data list.
  3. Activate the recirculation switch.

Does the scan tool indicate the Recirculate Button parameter changes state?

--

Go to Step 3

Go to Step 11

3
  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 recirculation switch in the ON position.
  5. Place the recirculation switch in the OFF position.

Does the recirculation door move from the recirculation position to the ambient air position?

--

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

Go to Step 4

4

With a scan tool, command the recirculation mode valve solenoid (Sol. 4-Air Inlet) ON and OFF.

Does the recirculation mode valve solenoid turn ON and OFF?

--

Go to Vacuum Test

Go to Step 5

5

  1. Turn OFF the ignition.
  2. Disconnect the vacuum control assembly.
  3. Turn ON the ignition, with the engine OFF.
  4. Probe circuit 41 of the vacuum control assembly with a test lamp that is connected to a good ground.

Does the test lamp illuminate?

--

Go to Step 6

Go to Step 12

6

  1. Measure the voltage between circuit 41 of the vacuum control assembly and the circuit 363 of the vacuum control assembly.
  2. With a scan tool, command the recirculation mode valve solenoid ON and OFF.

Does the measured voltage change between the specified values?

0-12 V

Go to Step 10

Go to Step 7

7

Does the measured voltage remain near the specified value?

12 V

Go to Step 9

Go to Step 8

8

Test the circuit 363 of the vacuum control assembly for a short to voltage or an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 15

Go to Step 11

9

Test the circuit 363 of the vacuum control assembly for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 15

Go to Step 10

10

Inspect for poor connections at the vacuum control assembly. 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 15

Go to Step 13

11

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 15

Go to Step 14

12

Repair the circuit 41 of the vacuum control assembly. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

--

Go to Step 15

--

13

Replace the vacuum control assembly. Refer to Vacuum Electrical Solenoid Replacement .

Did you complete the replacement?

--

Go to Step 15

--

14

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

Did you complete the replacement?

--

Go to Step 15

--

15

Operate the system in order to verify the repair.

Did you correct the condition?

--

System OK

Go to Step 4