GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

1

Did you perform the HVAC Compressor Controls System Check?

--

Go to Step 2

Go to HVAC Compressor Controls System Check

2

Inspect the A/C Compressor fuse at the Underhood Fuse/Relay Center.

Is the fuse operational?

--

Go to Step 4

Go to Step 3

3

  1. Locate the overload.
  2. Replace the Underhood A/C Compressor Fuse.

Is the repair complete?

--

Go to HVAC Compressor Controls System Check

--

4

Inspect the IGN -E fuse at the Underhood Fuse/Relay Center.

Is the fuse operational?

--

Go to Step 6

Go to Step 5

5

  1. Locate the overload.
  2. Replace the IGN -E Fuse.

Is the repair complete?

--

Go to HVAC Compressor Controls System Check

--

6

  1. Disconnect the vehicle control module (VCM).
  2. Place the ignition switch in the RUN position.
  3. Turn on the air conditioning (A/C).
  4. Connect a test lampJ 35616-200 from the CKT 762 (DK GRN/WHT) cavity 25 of the VCM connector C3 to ground.

Did the test lamp light?

--

Go to Step 7

Go to Step 8

7

Connect a DMM J 39200 from CKT

 603 (DK GRN/WHT) cavity 30 of the VCM connector C3 to ground

Is there continuity?

--

Go to Step 9

Go to Step 10

8

  1. Disconnect the A/C high-pressure cut-off switch.
  2. Connect a test lampJ 35616-200 from CKT 66 (LT GRN/WHT) cavity B of the A/C high pressure cut-off switch connector to ground.

Did the test lamp light?

--

Go to Step 11

Go to Step 12

9

Connect a test lampJ 35616-200 from CKT 459 (DK GRN/WHT) cavity 1 of the VCM connector C3 to ground.

Did the test lamp light?

--

Go to Step 13

Go to Step 14

10

  1. Place the ignition switch in the OFF position.
  2. Disconnect the A/C low-pressure cut-off switch.
  3. Connect a DMM J 39200 from CKT 850 (BLK) cavity A of the switch connector to ground.

Is there continuity?

--

Go to Step 21

Go to Step 22

11

Use a J 39200 Digital Multimeter (DMM) in order to test the CKT 762 (DK GRN/WHT) for resistance between the A/C high-pressure cut-off switch cavity A and cavity 25 of the VCM connector C3.

Does the DMM show continuity?

--

Go to Step 15

Go to Step 16

12

Connect a test lamp J 35616-200 from CKT 66 (LT GRN) cavity H of the HVAC control module connector C2 to ground.

Did the test lamp light?

--

Go to Step 17

Go to Step 18

13

  1. Place the ignition switch in the OFF position.
  2. Reconnect the VCM.
  3. Disconnect the A/C compressor clutch connector.
  4. Place the ignition switch in the RUN position.
  5. Connect a test lamp J 35616-200 from CKT 59 (DK GRN) cavity B of the A/C compressor clutch connector to ground.

Did the test lamp light?

--

Go to Step 19

Go to Step 27

14

  1. Disconnect the A/C enable relay.
  2. Connect a test lamp J 35616-200 from the A/C enable relay CKT 639 (PNK) cavity D6 to ground.

Did the test lamp light?

--

Go to Step 20

Go to Step 28

15

Replace the A/C high-pressure cut-off switch.

Is the repair complete?

--

Go to HVAC Compressor Controls System Check

--

16

Repair the open in CKT 762 (DK GRN/WHT) between the A/C high pressure cut-off switch and the VCM.

Is the repair complete?

--

Go to HVAC Compressor Controls System Check

--

17

Repair the open in CKT 66 (LT GRN) between the HVAC control module and the A/C high-pressure cut-off switch.

Is the repair complete?

--

Go to HVAC Compressor Controls System Check

--

18

  1. Disconnect the HVAC Control Module Connector.
  2. Connect a test lamp J 35616-200 from CKT 141 (BRN) cavity E of the HVAC control module connector C2 to ground.

Did the test lamp light?

--

Go to Step 25

Go to Step 26

19

Use a J 39200 DMM in order to test for resistance from CKT 850 (BLK) cavity A of the A/C compressor clutch connector to ground.

Does the DMM show continuity?

--

Go to Step 32

Go to Step 35

20

  1. Connect a fused jumper between the A/C enable relay CKT 459 (DK GRN/WHT) cavity C4 to CKT 639 (PNK).
  2. Connect a test lamp J 35616-200 from the VCM connector C2 CKT 459 (DK GRN/WHT) to ground.

Did the test lamp light?

--

Go to Step 36

Go to Step 31

21

Use a J 39200 DMM in order to test CKT 603 (DK GRN) for resistance between the switch and cavity 30 of the VCM connector  C3.

Does the DMM show continuity?

--

Go to Step 23

Go to Step 24

22

Repair the open in CKT 850 (BLK) between the A/C low cut-off pressure switch and ground G104.

Is the repair complete?

--

Go to HVAC Compressor Controls System Check

--

23

Replace the A/C low-pressure cut-off switch.

Is the repair complete?

--

Go to HVAC Compressor Controls System Check

--

24

Repair the open in CKT 603 (DK GRN) between the A/C low-pressure cut-off switch and the VCM.

Is the repair complete?

--

Go to HVAC Compressor Controls System Check

--

25

Replace the HVAC control module.

Refer to Control Assembly Replacement .

Is the repair complete?

--

Go to HVAC Compressor Controls System Check

--

26

Repair the open in CKT 141 (BRN) between the instrument panel fuse block and the HVAC control module.

Is the repair complete?

--

Go to HVAC Compressor Controls System Check

--

27

Connect a test lamp J 35616-200 from the A/C enable relay CKT 1240 (ORN) cavity C6 and ground.

Did the test lamp light?

--

Go to Step 30

Go to Step 29

28

Repair the open in CKT 639 (PNK) between the A/C enable relay (underhood fuse-relay center) and the ignition-E fuse (underhood fuse-relay center).

Is the repair complete?

--

Go to HVAC Compressor Controls System Check

--

29

Repair the open in CKT 1240 (ORN) between the A/C enable relay (underhood fuse-relay center) and the A/C compressor fuse (underhood fuse-relay center).

Is the repair complete?

--

Go to HVAC Compressor Controls System Check

--

30

  1. Remove the A/C Enable Relay.
  2. Connect a fused jumper between the A/C enable relay CKT 1240 (ORN) cavity C6 and CKT 59 (GRN) cavity D4.
  3. Connect a test lamp J 35616-200 from the A/C compressor clutch connector CKT 59 (DK GRN) to ground.

Did the test lamp light?

--

Go to Step 36

Go to Step 33

31

Repair the open in CKT 459 (DK GRN/WHT) between the A/C enable relay and the VCM.

Is the repair complete?

--

Go to HVAC Compressor Controls System Check

--

32

Use a J 39200 DMM in order to test for resistance between Pin B and Pin A of the A/C compressor clutch.

Is the resistance less than the recommended value?

10 ohms

Go to Powertrain On Board Diagnostic (OBD) System Check

Go to Step 34

33

Repair the open in CKT 59 (DK GRN) between the A/C enable relay and the A/C compressor clutch.

Is the repair complete?

--

Go to HVAC Compressor Controls System Check

--

34

Replace the A/C compressor clutch. Refer to Compressor Clutch Plate/Hub Assembly Installation (HT6/HD6).

Is the repair complete?

--

Go to HVAC Compressor Controls System Check

--

35

Repair the open in CKT 850 (BLK) between the A/C compressor clutch and ground G104.

Is the repair complete?

--

Go to HVAC Compressor Controls System Check

--

36

Replace the A/C Enable Relay.

Is the repair complete?

--

Go to HVAC Compressor Controls System Check

--