GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

1

Were you sent here from the Cooling Insufficient, A/C System diagnostic table?

--

Go to Step 2

Go to Cooling Insufficient - Air Conditioning (A/C) System

2

Visually inspect for restricted air flow at the condenser.

Is the air flow through the condenser restricted?

--

Go to Step 3

Go to Step 4

3

Repair the air flow restriction condition or replace the condenser, if damaged. Refer to Condenser Replacement .

Is the repair complete?

--

Go to Step 9

--

4

Start the engine and turn the A/C ON.

Are the cooling fan(s) ON and operating properly?

--

Go to Step 6

Go to Step 5

5

Repair the cooling fan operation fault. Refer to Electric Cooling Fan Diagnosis in Engine Controls - 3.4L or Electric Cooling Fan Diagnosis in Engine Controls - 3.8L.

Is the repair complete?

--

Go to Step 9

--

6

  1. The engine still idling in PARK.
  2. The A/C still turned ON.
  3. Feel the liquid line on both sides of the expansion (orifice) tube.

Is the temperature the same before and after the orifice?

--

Go to Step 7

Go to Step 8

7

Turn the engine OFF.

Replace the damaged/faulty expansion (orifice) tube (orifice opening too large and/or the O-ring is damaged or missing). Refer to Expansion (Orifice) Tube Replacement .

Is the repair complete?

--

Go to Step 9

--

8

  1. Turn the engine OFF.
  2. Air is in the refrigerant system, or the system is overcharged.
  3. Verify A/C system capacity. Refer to System Capacities .
  4. Recover, Evacuate and Recharge A/C system to specifications. Refer to Refrigerant Recovery and Recharging .

Is the repair complete?

--

Go to Step 9

--

9

Take readings of the low and high side pressures as well as the IP center outlet air temperatures after repairs are performed.

Compare the pressures and outlet temperatures to those listed in the A/C Performance Table. Refer to Cooling Insufficient - Air Conditioning (A/C) System .

Are the readings within the specified ranges?

--

Got to Step 10

Go to Cooling Insufficient - Air Conditioning (A/C) System

10

Operate the system in order to verify the repair.

Did you correct the condition?

--

Got to Step 11

Go to Symptoms in HVAC Systems - Manual

11

  1. Disconnect the J 39500-B .
  2. Install the LH diagonal brace. Refer to Front Fender Upper Diagonal Brace Replacement in Body Front End.
  3. Install the cross vehicle brace. Refer to Cross Vehicle Brace Replacement in Body Front End.

Is the action complete?

--

System OK

--