GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

1

Has the HVAC Diagnostic System Check been performed?

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Go to Step 2

Go to Diagnostic System Check

2

  1. Install a scan tool.
  2. Start the engine and allow to idle.
  3. Display the PCM Eng 2 Data List.
  4. Turn the A/C button ON.

Does the scan tool indicate the A/C Relay Command is ON?

--

Go to Step 5

Go to Step 3

3

Does the scan tool indicate the A/C Request is YES?

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Go to Step 8

Go to Step 4

4

  1. Display the HVAC Inputs screen.
  2. Press the A/C button.

Does the scan tool indicate the A/C button is ON while the button is pressed?

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Go to Step 8

Go to Step 9

5

Test and repair the clutch coil feed circuit 59 for an open or high resistance. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

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Go to Step 10

Go to Step 6

6

Test and repair the clutch coil ground circuit 150 for an open or high resistance. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

--

Go to Step 10

Go to Step 7

7

Replace the A/C compressor clutch. Refer to Compressor Clutch Coil Removal (V7 - Direct Mount) .

Is the repair complete?

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Go to Step 10

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8

Replace the PCM. Refer to Powertrain Control Module Replacement .

Is the repair complete?

--

Go to Step 10

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9

Replace the HVAC Control Assembly. Refer to Control Assembly Replacement .

Is the repair complete?

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Go to Step 10

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10

  1. Clear any DTCs which may have set.
  2. Operate the system in order to verify the repair.

Did you correct the condition?

--

System OK

Go to Diagnostic System Check