GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Buick 🢒 2001 🢒 LeSabre 🢒 DTC 🢒 DTC B0269

Circuit Description

The recirculation actuator is an electronic device that incorporates a stepper motor and feedback potentiometer. The instrument panel integration module (IPM) controls the recirculation door position by sending a control signal to the actuator. The signal's value is dependent upon the desired setting selected by the vehicle occupants. The control signal is near 0 V when the recirculation actuator is commanded toward the outside air position, near 5 V when commanded toward the recirculation position, and near 2.5 V when stationary. As the recirculation actuator moves, the potentiometer produces the actual door position signal that is sent to the IPM. The IPM continues to command the actuator to move until the desired and actual values are equal.

When a calibration or recalibration procedure is performed, the IPM calculates the recirculation door travel range. The IPM commands the actuator through it's full range. The IPM stores the learned minimum and maximum position values. The travel range value is calculated by subtracting the minimum position value from the maximum position value. The IPM compares the travel range to calibrated limits. If the travel range value is less than or equal to the maximum calibrated limit and greater than or equal to the minimum calibrated limit, then the calibration is considered successful. The IPM continuously compares the actual actuator position to the calibrated minimum and maximum position values.

Conditions for Running the DTC
    • The range fault code can only be set following a calibration/recalibration of the recirculation actuator.
    • The IPM will not perform a calibration/recalibration of the recirculation actuator if DTC B0272 is set as current.

Conditions for Setting the DTC

The actual total travel range of the recirculation door (max - min) is less than 149 counts (2.9 volts) or greater than 220 counts (4.3 volts).

Action Taken When the DTC Sets
    • The IPM will continue to make use of whatever travel range is still available.
    • The IPM will recalibrate the recirculation door travel range each time the ignition switch is turned ON.

Conditions for Clearing the DTC
    • A successful recalibration of the recirculation door must be completed.
    • A history DTC clears after 50 malfunction free ignition cycles.
    • The IPM receives the clear code command from the scan tool.

Diagnostic Aids
    • The calibration limit is 149-220 counts (2.9-4.3 V). An actual range below this limit suggests an obstruction of the recirculation door or a binding linkage limiting travel. An actual range above this limit suggests an over travel condition (damaged or missing foam seals).
    • If the condition is not present, refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.

Test Description

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

  1. A total travel range greater than 15 counts indicates a mechanical malfunction with the door or linkage, causing an over travel or under travel condition. A total travel range less than 15 counts indicates an electrical malfunction, binding door, or binding linkage.

  1. This step uses the fused jumper wire to drive the actuator to its maximum and minimum positions. Use the scan tool to determine the total travel range of the actuator (maximum position - minimum position).

Step

Action

Values

Yes

No

Schematic Reference: HVAC Schematics

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
  1. With a scan tool, observe the Min. Air Inlet Dr. Pos and Max. Air Inlet Dr. Pos parameters in the Instrument Panel Module data list.
  2. Subtract the value of the Min Air Inlet Dr. Pos parameter from the value of the Max Air Inlet Dr. Pos parameter.

Does the result of the calculation indicate that the total travel of the recirculation door is within the specified range?

149-220 Counts

(2.9-4.3 V)

Go to Diagnostic Aids

Go to Step 3

3

Does the result of the calculation indicate that the total travel range of the recirculation door is greater than the specified value?

15 Counts

(0.3 V)

Go to Step 10

Go to Step 4

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

Does the test lamp illuminate?

--

Go to Step 5

Go to Step 13

5

Measure the voltage from the 5 volt reference circuit of the recirculation actuator to a good ground.

Does the voltage measure near the specified value?

5 V

Go to Step 6

Go to Step 9

6

Important: The ignition must be cycled from OFF to ON with the mode actuator disconnected during this step. Failure to do this may result in misdiagnosis.

  1. Turn the ignition OFF.
  2. Turn the ON the ignition, with the engine OFF.
  3. Measure the voltage from the recirculation door control circuit of the recirculation actuator to a good ground.

Does the voltage measure within the specified range?

2.3-2.7 V

Go to Step 8

Go to Step 7

7

Test the door control circuit of the recirculation actuator 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 16

Go to Step 12

8

Important: The mode actuator connector and the instrument panel integration module connector must be connected during this step in order to avoid misdiagnosis.

  1. Turn the ignition OFF.
  2. Connect the recirculation actuator.
  3. Turn ON the ignition, with the engine OFF.
  4. With the scan tool, observe the Air Inlet Dr Actual parameter in the Instrument Panel Module HVAC Door Positions data list.
  5. Connect a 3-amp fused jumper wire between the recirculation door control circuit and the 5 volt reference circuit of the recirculation actuator (drives the actuator toward the recirculation position).
  6. Remove and reconnect the jumper wire between the recirculation door control circuit and the low reference circuit of the recirculation actuator (drives the actuator toward the outside air position).

Does the scan tool indicate that the total travel range of the recirculation door is greater than the specified value?

15 Counts

Go to Step 12

Go to Step 10

9

Test the 5 volt reference circuit of the recirculation actuator for an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 16

Go to Step 12

10

Inspect the recirculation door and the recirculation actuator for the following conditions.

    • A misaligned recirculation actuator. Refer to Recirculation Actuator Replacement .
    • Broken or binding linkages or recirculation door
    • An obstruction that prevents the recirculation actuator from operating within it's full range of motion
    • Missing seals to the recirculation door
    • Misaligned seals to the recirculation door

Did you find and correct the condition?

--

Go to Step 16

Go to Step 11

11

Inspect for poor connections at the harness connector of the recirculation 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 16

Go to Step 14

12

Inspect for poor connections at the harness connector 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 16

Go to Step 15

13

Repair the ignition 3 voltage circuit of the recirculation actuator. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

--

Go to Step 16

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14

Important: Recalibrate the recirculation actuator.

Replace the recirculation actuator. Refer to Recirculation Actuator Replacement .

Did you complete the replacement?

--

Go to Step 16

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15

Important: Recalibrate the IPM.

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

Did you complete the replacement?

--

Go to Step 16

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16
  1. Use the scan tool in order to clear the DTCs.
  2. Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text.

Does the DTC reset?

--

Go to Step 2

System OK