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Makes 🢒 Buick 🢒 2001 🢒 Regal (China) 🢒 HVAC 🢒 HVAC Systems - Manual 🢒 Air Recirculation Malfunction

Air Recirculation Malfunction CJ4

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 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 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 - HVAC Systems - Manual

2
  1. Install a scan tool.
  2. Turn ON the ignition, with the engine OFF.
  3. With a scan tool, observe the Recirculate Button parameter in the Heating and Air Conditioning data list.
  4. Activate the recirculation switch.

Does the scan tool indicate that 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 Step 4

Go to Step 5

4
  1. Place the auxiliary recirculation switch in the ON position.
  2. Place the auxiliary recirculation switch in the OFF position.

Does the recirculation door operate properly?

--

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

Go to Step 13

5
  1. Measure the voltage from the auxiliary recirculation/A/C request signal circuit of the HVAC control module to a good ground.
  2. Activate the auxiliary recirculation switch.

Does the measured voltage change?

--

Go to Step 7

Go to Step 6

6

Test the auxiliary recirculation/A/C request signal circuit of the HVAC control module for an open, short to ground or short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 22

Go to Step 16

7

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 Control System Diagnostic

Go to Step 8

8

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

Does the test lamp illuminate?

--

Go to Step 9

Go to Step 18

9

  1. Measure the voltage between the ignition-3 voltage circuit of the vacuum control assembly and the recirculation mode valve solenoid control circuit 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 15

Go to Step 10

10

Does the measured voltage remain near the specified value?

12 V

Go to Step 12

Go to Step 11

11

Test the recirculation mode valve solenoid control circuit 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 22

Go to Step 17

12

Test the recirculation mode valve solenoid control circuit 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 22

Go to Step 17

13
  1. Measure the voltage from the auxiliary recirculation/A/C request signal circuit of the HVAC control module to a good ground.
  2. Activate the auxiliary recirculation switch.

Does the measured voltage change?

--

Go to Step 17

Go to Step 14

14

Test the auxiliary recirculation/A/C request signal circuit of the HVAC control module for an open, short to ground or short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 22

Go to Step 16

15

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 22

Go to Step 19

16

Inspect for poor connections at the harness connector of the auxiliary 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 22

Go to Step 20

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 22

Go to Step 21

18

Repair the ignition-3 voltage circuit of the vacuum control assembly. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

--

Go to Step 22

--

19

Replace the vacuum control assembly. Refer to Vacuum Control Assembly Replacement .

Did you complete the replacement?

--

Go to Step 22

--

20

Replace the auxiliary HVAC control module. Refer to Auxiliary Heater and Air Conditioning Control Replacement .

Did you complete the replacement?

--

Go to Step 22

--

21

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

Did you complete the replacement?

--

Go to Step 22

--

22

Operate the system in order to verify the repair.

Did you correct the condition?

--

System OK

Go to Step 4