GM Service Manual Online
For 1990-2009 cars only

Step

Action

Values

Yes

No

1

Measure the voltage at terminal 4 of the intake motor.

Is the voltage within the specified range?

11-14 V

Go to Step 3

Go to Step 2

2

  1. Inspect the connector and circuit for any wiring or terminal problems
  2. Repair any problems found.

Is the repair complete?

--

System OK

--

3

  1. To measure the voltages at the specified terminals of the motor connector, refer to the Intake Control Table .
  2. Change the intake setting and observe the voltage changes.

Are these voltages within the specified value?

--

Go to Step 4

Go to Step 5

4

Replace the intake motor. Refer to Recirculation Actuator Replacement .

Is the repair complete?

--

System OK

--

5

  1. Refer to the Intake Control Table to measure the voltages at the specified terminals of the controller connector.
  2. Change the intake setting and observe the voltage changes.

Are these voltages within the Motor Control table?

--

Go to Step 6

Go to Step 7

6

  1. Inspect the wiring harness and connectors between the controller and the motor that is not performing properly.
  2. Repair or replace the wiring harness or the defective terminal.

Is the repair complete?

--

System OK

--

7

Inspect the connector at the controller.

Is there a defective terminal?

--

Go to Step 8

Go to Step 9

8

Repair or replace the terminal.

Is the repair complete?

--

System OK

--

9

Replace the controller. Refer to Heater and Air Conditioning Control Replacement .

Is the repair complete?

--

System OK

--