GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

1

Inspect the control cables from the heater control unit to the heater case and to the blower case for proper routing, kinks, and interference.

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

--

Go to Step 6

Go to Step 2

2

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

Does the door bind?

--

Go to Step 4

Go to Step 3

3

Inspect for control binding.

Does the control bind?

--

Go to Step 5

Go to Step 11

4

  1. Remove the heater case. Refer to Heater Case Replacement .
  2. Inspect the door seal for proper installation.

Is the door seal OK?

--

Go to Step 8

Go to Step 7

5

  1. Remove the heater control unit. Refer to Control Assembly Replacement .
  2. Disconnect the control cable from the heater control unit.
  3. Inspect the control cable for binding.

Does the control cable bind?

--

Go to Step 9

Go to Step 10

6

  1. Route the control cables in order to avoid interference.
  2. Replace the control cables if the cables are kinked.

Is the repair complete?

--

Go to Step 12

--

7

Repair the door seal as necessary.

Is the repair complete?

--

Go to Step 12

--

8

  1. Inspect for a bent door shaft and/or a warped heater case.
  2. Repair the door shaft and the heater case as needed.

Is the repair complete?

--

Go to Step 12

--

9

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

Is the repair complete?

--

Go to Step 12

--

10

Replace the corresponding control cable. Refer to Temperature Control Cable Replacement , Mode Control Cable Replacement or Vent Control Cables Replacement .

Is the repair complete?

--

Go to Step 12

--

11

  1. Reinstall the control cable.
  2. Verify the proper clearance to the IP components.
  3. Repair as necessary.

Is the action complete?

--

Go to Step 12

--

12

Perform the functional test. Refer to Function Test .

Is the action complete?

--

System OK

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