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Makes 🢒 Cadillac 🢒 2008 🢒 XLR 🢒 Diagnostic Navigation 🢒 Programming and Setup 🢒 Air Conditioning (A/C) Diagnostics - Pressure Zone A

Step

Action

Value

Yes

No

DEFINITION: The high and low side pressures may be normal or slightly less than normal.

    • Air Delivery Concern
    • Slight Refrigerant Under Charge
    • Refrigerant Contamination

1

Were you sent here from the A/C System Performance Test?

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Go to Step 2

Go to Air Conditioning (A/C) System Performance Test

2

Refer to the panel air outlet temperatures recorded during the A/C system performance test.

Does the discharge air temperature between the right and left center panel outlets vary by more than 2-3°C (3-4°F)?

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Go to Step 7

Go to Step 3

3

Did the customer mention that the A/C system output temperatures are good at first, but then turn warm during extended drives?

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Go to Step 4

Go to Step 5

4

Increase engine speed to 2,000 RPM.

During extended operation of the A/C system, does the low side pressure decrease?

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Go to Air Conditioning (A/C) Diagnostics - Pressure Zone D

Go to Step 5

5

Refer to the pressures recorded during the A/C system performance test.

Inspect for the following conditions:

Caution: Refer to Moving Parts and Hot Surfaces Caution in the Preface section.

    • The high side pressure is slightly greater than the specified pressure ranges but still within Zone A on the A/C Pressure-Zone Classification Chart in the A/C System Performance Test. Refer to Air Conditioning (A/C) System Performance Test .
    • The discharge side of the compressor hose assembly is hot.
    • The suction side of the compressor hose assembly is cool.

Do the listed conditions exist?

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Go to Step 7

Go to Step 6

6

Refer to the pressures recorded during the A/C system performance test.

Inspect for the following conditions:

    • The low side pressure is slightly lower than the specified pressure ranges but still within Zone A on the A/C Pressure-Zone Classification Chart in the A/C System Performance Test. Refer to Air Conditioning (A/C) System Performance Test .
    • The discharge side of the compressor hose assembly is warm-to-hot.
    • The suction side of the compressor hose assembly is cool-to-warm.

Do the listed conditions exist?

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Go to Step 8

Go to Air Temperature Malfunction

7

The A/C system may be undercharged.

  1. Leak test A/C system. Refer to Leak Testing .
  2. Recharge the A/C system to specifications. Refer to Refrigerant Recovery and Recharging .

Is the repair complete?

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Go to Step 14

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8

The A/C system may be contaminated.

View the J 43600 ACR 2000 information screen for detection of foreign gases in the A/C system.

Do foreign gases exist?

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Go to Step 9

Go to Step 10

9
  1. Evacuate the A/C system to a scavenging tank. Refer to Refrigerant Recovery and Recharging .
  2. Recharge the A/C system to specifications.

Is the repair complete?

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Go to Step 14

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10

The A/C system may contain too much moisture or air.

  1. Evacuate and recharge the A/C system to specifications. Refer to Refrigerant Recovery and Recharging .
  2. Operate the A/C system and inspect the panel outlet air temperatures. Refer to Air Conditioning (A/C) System Performance Test .

Are the panel outlet temperatures within the specified ranges of the A/C Performance Test Table?

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Go to Step 14

Go to Step 11

11

The A/C system may contain too much refrigerant oil.

    Important: Operate the A/C system on low, in order to enhance oil flow to the high side of the system.

  1. Operate the A/C system with the engine at idle speed and the blower speed on low for approximately 15 minutes.
  2. Recover the refrigerant from the A/C system. Refer to Refrigerant Recovery and Recharging .
  3. Remove the condenser. Refer to Condenser Replacement .
  4. Drain and measure the refrigerant oil from the condenser.

Was more than the specified amount of refrigerant oil drained from the condenser?

150 ml (5 oz)

Go to Step 12

Go to Step 13

12
  1. Install the condenser. Refer to Condenser Replacement .
  2. Flush the A/C system. Refer to Flushing .
  3. Recharge the A/C system. Refer to Refrigerant Recovery and Recharging .

Are the repairs complete?

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Go to Step 14

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13
  1. Add the specified amount of refrigerant oil to the condenser. Refer to Refrigerant System Capacities .
  2. Install the condenser. Refer to Condenser Replacement .
  3. Recharge the A/C system. Refer to Refrigerant Recovery and Recharging .

Are the repairs complete?

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Go to Step 14

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14

Operate the system in order to verify the repair.

Did you find and correct the condition?

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System OK

Go to Symptoms - HVAC Systems - Automatic