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Home >> Chevrolet >> 2002 >> Blazer 4D Utility, 4WD, Part Time >> Repair and Diagnosis >> External Pages >> Different car >> Section 1909 (Heating, Ventilation, And Air Conditioning) >> Diagnostic Information and Procedures >> Air Conditioning (A/C) Diagnostics - Pressure Zone C

Air Conditioning (A/C) Diagnostics - Pressure Zone C

WARNING: This page is about a different car, the 2009 Saturn Vue. However, it is still accessible from the selected car via links, so may be relevant.
Step Action Yes No
DEFINITION: The low and the high side pressures are both higher than normal.
  • Restricted Condenser Air Flow
  • Cooling Fan Malfunction
  • Thermal Expansion Valve (TXV) Malfunction
1 Were you sent here from the air conditioning (A/C) System Performance Test? Go to Step 2  Go to Air Conditioning (A/C) System Performance Test (LY7)  or Air Conditioning (A/C) System Performance Test (LZ4)  or Air Conditioning (A/C) System Performance Test (LE5)  or Air Conditioning (A/C) System Performance Test (LY7 Red Line)  or Air Conditioning (A/C) System Performance Test (LAT Green Line)  or Air Conditioning (A/C) System Performance Test (HP5) 
2
  1. Start the engine.
  2. Turn ON the A/C.
  3. Inspect for proper cooling fan operation. Refer to Cooling Fan Inoperative (LAT) or Cooling Fan Inoperative (LE5) or Cooling Fan Inoperative (LCS) .
Are the cooling fans ON and operating properly?
Go to Step 3  Go to Step 5 
3 Visually inspect for the following conditions:
  • Damaged condenser cooling fins
  • Missing or misaligned air baffles
  • Restricted air flow

Do any of these conditions exist?
Go to Step 4  Go to Step 6 
4 Repair the air flow restriction.
Is the action complete?
Go to Step 9  -
5 Repair the fault to the cooling fan operation. Refer to Cooling Fan Inoperative (LAT) or Cooling Fan Inoperative (LE5) or Cooling Fan Inoperative (LCS) .
Is the repair complete?
Go to Step 9  -
6 Feel the liquid line on both sides of the thermal expansion valve (TXV).Are the temperatures on both sides of the TXV similar? Go to Step 7  Go to Step 8 
7 Replace the damaged or faulty TXV. Refer to Air Conditioning Evaporator Thermal Expansion Valve Replacement .
Is the action complete?
Go to Step 9  -
8
  1. Air is in the refrigerant system, or the system is overcharged. Refer to the view screen on J 43600  ACR 2000 Air Conditioning Service Center for foreign gas content in the refrigerant. See Special Tools .
  2. Recover and recharge the A/C system. Refer to Refrigerant Recovery and Recharging (With HP5)  or Refrigerant Recovery and Recharging (Without HP5) .
Is the action complete?
Go to Step 9  -
9
  1. Record the low and high side pressures and the instrument panel outlet air temperature after you have performed the repairs.
  2. Compare the pressures and the instrument panel outlet air temperature to those listed in the A/C Performance Chart. Refer to Air Conditioning (A/C) System Performance Test (LY7)  or Air Conditioning (A/C) System Performance Test (LZ4)  or Air Conditioning (A/C) System Performance Test (LE5)  or Air Conditioning (A/C) System Performance Test (LY7 Red Line)  or Air Conditioning (A/C) System Performance Test (LAT Green Line)  or Air Conditioning (A/C) System Performance Test (HP5) .
Are the readings within the specified ranges listed in the A/C Performance Chart?
Go to Step 10  Go to Air Conditioning (A/C) System Performance Test (LY7)  or Air Conditioning (A/C) System Performance Test (LZ4)  or Air Conditioning (A/C) System Performance Test (LE5)  or Air Conditioning (A/C) System Performance Test (LY7 Red Line)  or Air Conditioning (A/C) System Performance Test (LAT Green Line)  or Air Conditioning (A/C) System Performance Test (HP5) 
10 Operate the system in order to verify the repair.
Did you find and correct the condition?
System OK Go to Symptoms - HVAC Systems - Manual or Symptoms - HVAC Systems - Automatic .