Air Conditioning (A/C) Diagnostics - Pressure Zone A
WARNING: This page is about a different car, the 2010 Pontiac G5 and 2010 Chevrolet Cobalt. However, it is still accessible from the selected car via links, so may be relevant.
| Step | Action | Value | Yes | No |
|---|---|---|---|---|
DEFINITION: The high and low side pressures may be normal or slightly less than normal.
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| 1 | Were you sent here from the A/C System Performance Test? | - | Go to Step 2 | Go to Air Conditioning (A/C) System Performance Test (LNF) |
| 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 4°C (5°F)? |
- | 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? | - | 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, possibly accompanied by heavy frost on the liquid line between the expansion device and the evaporator? |
- | 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:
WARNING:
Refer to Moving Parts and Hot Surfaces Warning
.
Do the listed conditions exist? |
- | 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:
Do the listed conditions exist? |
- | Go to Step 8 | Go to Air Temperature Malfunction |
| 7 | The A/C system may be undercharged.
Is the repair complete? |
- | Go to Step 13 | - |
| 8 | The A/C system may be contaminated. View the J 43600 ACR 2000 Air Conditioning Service Center information screen for detection of foreign gases in the A/C system. See Special Tools . Do foreign gases exist? |
- | Go to Step 9 | Go to Step 10 |
| 9 |
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- | Go to Step 13 | - |
| 10 | The A/C system may contain too much moisture or air.
Are the panel outlet temperatures within the specified ranges of the A/C Performance Test Table? |
- | Go to Step 14 | Go to Step 11 |
| 11 |
NOTE:
Review the vehicles A/C repair history. If the vehicle history shows multiple A/C repairs and is suspected of improper polyalkylene glycol (PAG) oil balancing in the previous repairs, perform the following procedure: Was more than the total system capacity of refrigerant oil recovered from the J 43600
oil drain bottle? See Special Tools .
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148 ml (5 oz) | Go to Step 12 | Go to Step 12 |
| 12 |
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- | Go to Step 13 | - |
| 13 |
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- | Go to Step 14 | Go to Air Conditioning (A/C) System Performance Test (LNF) |
| 14 | Operate the system in order to verify the repair. Did you find and correct the condition? |
- | System OK | Go to Symptoms - HVAC Systems - Manual |