GM Service Manual Online
For 1990-2009 cars only

Step

Action

Yes

No

1

Did you perform the function test?

Go to Step 2

Go to Function Test

2

  1. Inspect the control cables from the heater control unit to the heater case.
  2. Inspect for any improper routing, kinks, and interference.

Do any of the control cables have improper routing, kinks, or interference?

Go to Step 6

Go to Step 3

3

  1. Disconnect the control cable from the door that causes the binding.
  2. Cycle the door manually.

Does the door bind?

Go to Step 5

Go to Step 4

4

  1. Inspect the heater control unit for binding.
  2. Remove the heater control unit. Refer to Control Assembly Replacement .
  3. Disconnect the control cable from the heater control unit in order to determine if the cable or the control unit is binding.

Does control binding exist?

Go to Step 7

Go to Step 8

5

  1. Remove the heater case. Refer to HVAC Module Assembly Replacement .
  2. Inspect for the following conditions:
  3. • A damaged door seal
    • A bent door shaft
    • A warped heater case
  4. Replace the door seal or replace the heater case.

Is the repair complete?

Go to Function Test

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6

  1. Route the control cables in order to avoid interference with the instrument panel components.
  2. Replace any control cables that are kinked. Refer to the following:

Is the repair complete?

Go to Function Test

--

7

Replace the heater control unit. Refer to Control Assembly Replacement .

Is the repair complete?

Go to Function Test

--

8

Replace the corresponding control cable. Refer to the following:

Is the repair complete?

Go to Function Test

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