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?

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Go to Step 2

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

2

Did both the recorded low and high side pressures fall within zone B on the A/C Pressure-Zone Classification Graphic but after continued operation of the A/C system, did the low and high side pressures equalize or remained unchanged?

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Go to Step 5

Go to Step 3

3

Refer to the recorded pressures.

Check for the following conditions:

    • The low side pressure equal to or above the specified pressure range of the A/C Performance Table
    • The high side pressure is below the specified pressure range of the A/C Performance Table
    • The low side refrigerant line at the compressor feels cool to warm
    • The high side refrigerant line at the compressor feels warm to hot

Do the listed conditions exist?

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Go to Step 6

Go to Step 4

4

Check for the following conditions:

    • The low side pressure is above the specified pressure range of the A/C Performance Table
    • The high side pressure is below the specified pressure range of the A/C Performance Table
    • The low side refrigerant line at the compressor feels warm
    • The high side refrigerant line at the compressor feels warm to hot

Do the listed conditions exist?

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Go to Step 5

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

5

The A/C compressor is malfunctioning. Replace the compressor. Refer to Air Conditioning Compressor Replacement .

Also replace the accumulator. Refer to Air Conditioning Accumulator Replacement

Is the repair(s) complete?

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Go to Step 7

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6

The A/C system has a low refrigerant charge. Evacuate and Recharge the A/C system to specifications. Refer to Refrigerant Recovery and Recharging

Is the repair complete?

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Go to Step 7

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7

  1. Take readings of the low and high side pressures as well as the I P outlet air temperatures after repairs are performed.
  2. Compare the low and high side pressures and IP outlet air 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?

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Go to Step 8

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

8

Operate the system in order to verify the repair

Did you correct the condition?

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Go to Step 9

Go to Diagnostic System Check in HVAC Systems - Manual

9

  1. Disconnect the J 39500-B .
  2. Install the air cleaner assembly. Refer to Air Cleaner Assembly Replacement in Engine Controls - 3.1L.

Is the action complete?

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System OK

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