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A/C Performance Test

WARNING: This page is about a different car, the 2014 Dodge Journey. However, it is still accessible from the selected car via links, so may be relevant.
WARNING:

Review the warnings and cautions for this system before performing the procedure. Failure to follow these instructions may result in serious injury or death.

CAUTION:

The use of an A/C recycling/charging station for purposes of determining the actual charge level of an A/C system is not recommend. Service recycling/charging stations do not reflect the correct amount of refrigerant charge in the A/C system after a single "reclaim" cycle. Tests have shown that it can take two or more "reclaim" cycles to remove all of the refrigerant charge, depending on the equipment being used. Use only the following procedure for determining the proper charge level.

NOTE:

When connecting the service equipment coupling to the line fitting, verify that the valve of the coupling is fully closed. This will reduce the amount of effort required to make the connection.

  1. Using a scan tool, check for Diagnostic Trouble Codes (DTCs) related to the Controller Area Network (CAN) data bus, Telematics Gateway (TGW), A/C heater module, Body Control Module (BCM) and Powertrain Control Module (PCM). If no DTCs are found, go to  2. If any DTCs are found, repair as required, then proceed to  2.
  2. Connect a tachometer and a manifold gauge set.
    NOTE:

    The ambient air temperature of the vehicle and the location where the vehicle will be tested must be a minimum of 21° C (70° F) before performing this test. Also the evaporator temperature sensor must be a minimum of 18° C (65° F) for this test as well. Place the vehicle in the testing area until the temperature within the vehicle reaches a minimum of 18° C (65° F).

  3. Operate the heating and A/C system under the following conditions.
    • Engine at normal operating temperature
    • Engine at normal idle speed
    • Door and windows closed
    • All air outlets fully open
    • Transaxle in Park
    • Front A/C and heater controls set to Recirculation mode, full cool, panel mode, high blower and with A/C compressor engaged. If the A/C compressor does not engage, see the A/C System Diagnosis table
    • If equipped with rear A/C, set rear controls to full cool and high blower
  4. Insert a thermometer in the driver side center panel air outlet and operate the A/C system until the thermometer temperature stabilizes or a minimum of 5 minutes.
    NOTE:

    This procedure requires the technician to know what the temperature and relative humidity is at the time of the test. The temperature must be combined with the relative humidity to calculate the apparent ambient temperature ("feels like" temperature), when the temperatures are above 21° C (70° F). Use the current ambient temperature and the relative humidity in your location. This information can be obtained from multiple sources, such as the internet or local news media.

  5. With the A/C compressor engaged, compare the air temperature at the center panel outlet and the compressor discharge pressure (high side) to the A/C Performance Temperature and Pressure chart.
    A/C PERFORMANCE TEMPERATURE AND PRESSURE

    Ambient Air Temperature (Apparent) 21° C
    (70° F)    		 27° C
    (80° F)    		 32° C
    (90° F)    		 38° C
    (100° F)    		 43° C
    (110° F)
    Air Temperature at Center Panel Outlet  9° C
    (48° F)    		 9° C
    (48° F)    		 12° C
    (54° F)    		 15° C
    (59° F)    		 24° C
    (75° F)
    Air Temperature at Driver Side 2nd Row Headliner Outlet  10° C
    (50° F)    		 13° C
    (55° F)    		 15° C
    (59° F)    		 17° C
    (63° F)    		 24° C
    (75° F)
    Suction Pressure at Service Port (Low Side)  138 to 310 kPa
    (20 to 45 psi)    		 138 to 345 kPa
    (20 to 50 psi)    		 207 to 365 kPa
    (30 to 55 psi)    		 207 to 414 kPa
    (30 to 60 psi)    		 241 to 448 kPa
    (35 to 65 psi)
    Discharge Pressure at Service Port (High Side)  1034 to 1724 kPa
    (150 to 250 psi)    		 1379 to 2068 kPa
    (175 to 300 psi)    		 1551 to 2241 kPa
    (175 to 325 psi)    		 1724 to 2413 kPa
    (250 to 350 psi)    		 2068 to 2758 kPa
    (300 to 475 psi)
  6. If the air outlet temperature fails to meet the specifications in the A/C Performance Temperature and Pressure chart, or if the compressor discharge pressure is high, see the A/C System Diagnosis table.
A/C SYSTEM DIAGNOSIS

Condition Possible Causes Correction
Rapid A/C compressor clutch cycling with poor panel outlet temperatures (fixed displacement compressors only). 1. Low refrigerant system charge. 1. See Refrigerant System Leaks in this group. Test the refrigerant system for leaks. Repair, evacuate and charge the refrigerant system, if required.
Equal low and high side pressures 1. No refrigerant in the refrigerant system. 1. See Refrigerant System Leaks in this group. Test the refrigerant system for leaks. Repair, evacuate and charge the refrigerant system, if required.
2. Inoperative A/C compressor or A/C clutch (depending on compressor application). 2. See A/C Compressor in this group. Test the compressor and/or A/C clutch and replace, if required.
3. Improperly installed or inoperative evaporator temperature sensor. 3. See Evaporator Temperature Sensor in this group. Correctly install or test the sensor and replace, if required.
4. Improperly installed or inoperative A/C pressure transducer. 4. See A/C High Pressure Transducer in this group. Test the transducer and replace, if required.
5. Inoperative control module, CAN bus or wiring. 5. See the appropriate Electrical Diagnostic Procedures for testing of the modules and CAN bus, and see Wiring Information for compressor control circuit repair, if required.
Normal refrigerant pressures, but A/C Performance Test air temperatures at center panel outlet are too high. 1. Excessive refrigerant oil in system. 1. See Refrigerant Oil Level in this group. Recover the refrigerant from the refrigerant system and inspect the refrigerant oil content. Restore the refrigerant oil to the proper level, if required.
2. Blend door actuator(s) improperly installed or inoperative. 2. See Blend Door Actuator this group. Inspect the actuator(s) for proper operation. Replace the actuator as required.
3. Blend-air door(s) inoperative or sealing improperly. 3. See HVAC Housing in this group. Inspect the blend-air door(s) for proper operation and sealing. Repair if required.
The low side pressure is normal or slightly low, and the high side pressure is too low. 1. Low refrigerant system charge. 1. See Refrigerant System Leaks in this group. Test the refrigerant system for leaks. Repair, evacuate and charge the refrigerant system, if required.
2. Refrigerant flow through the A/C evaporator is restricted. 2. See A/C Evaporator in this group. Replace the restricted A/C evaporator, if required.
3. Restricted refrigerant flow through the refrigerant lines. 3. See Plumbing in this group. Inspect the refrigerant lines for kinks, tight bends or improper routing. Correct the routing or replace the refrigerant line if required.
4. Inoperative A/C compressor. 4. See A/C Compressor in this group. Replace the compressor, if required.
The low side pressure is normal or slightly high, and the high side pressure is too high. 1. Inoperative radiator cooling fan. 1. See ENGINE COOLING SYSTEM . Test the radiator cooling fan and replace, if required.
2. A/C condenser air flow restricted. 2. See A/C Condenser in this group. Check the A/C condenser for damaged fins, foreign objects obstructing air flow through the condenser fins and missing or improperly installed air seals. Clean, repair or replace components as required.
3. Refrigerant flow through the A/C receiver/drier is restricted. 3. See A/C Receiver/Drier in this group. Replace the restricted A/C receiver/drier, if required.
4. Restricted refrigerant flow through the refrigerant lines. 4. See Plumbing in this group. Inspect the refrigerant lines for kinks, tight bends or improper routing. Correct the routing or replace the refrigerant line if required.
5. Refrigerant system overcharged. 5. See Refrigerant System Charge in this group. Recover the refrigerant from the refrigerant system. Charge the refrigerant system to the proper level, if required.
6. Air in the refrigerant system. 6. See Refrigerant System Leaks in this group. Test the refrigerant system for leaks. Repair, evacuate and charge the refrigerant system, if required.
7. Engine overheating. 7. See ENGINE COOLING SYSTEM . Test the engine cooling system and repair, if required.
The low side pressure is too high, and the high side pressure is too low. 1. Accessory drive belt slipping. 1. See ENGINE COOLING SYSTEM . Inspect the accessory drive belt condition and tension. Replace the accessory drive belt or tensioner, if required.
2. Inoperative A/C expansion valve. 2. See A/C Expansion Valve in this group. Replace the valve, if required.
3. Inoperative A/C compressor. 3. See A/C Compressor in this group. Replace the compressor, if required.
The low side pressure is too low, and the high side pressure is too high. 1. Restricted refrigerant flow through the refrigerant lines. 1. See Liquid Line, Suction Line and Discharge Line in this group. Inspect the refrigerant lines for kinks, tight bends or improper routing. Correct the routing or replace the refrigerant line, if required.
2. Restricted refrigerant flow through the A/C expansion valve. 2. See A/C Expansion Valve in this group. Replace the valve, if required.
3. Restricted refrigerant flow through the A/C condenser. 3. See A/C Condenser in this group. Replace the restricted condenser, if required.
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