INSPECTION AND VERIFICATION
Note. All Air Conditioning (A/C) related tests should be run in an ambient temperature of at least 10°C (50°F).
- Verify the customer concern by operating the system.
- Visually inspect for obvious signs of damage and system integrity. Visual Inspection Mechanical Electrical Coolant level Hose(s) Coolant pump Control flap(s) Duct(s) Vent(s) Cabin air filter Drive belt Air conditioning compressor Thermostatic expansion valve Evaporator Receiver drier Air conditioning condenser Refrigerant pipes Auxiliary drive belt Fuel fired booster heater Fuel fired booster heater fuel pump Fuel fired booster heater fuel pipes Fuse(s) Wiring harness Electrical connectors Blower Air conditioning compressor Electric cooling fan Automatic Temperature Control Module (ATCM) Refrigerant pressure sensor
- Listen for any unusual noises during climate control system operation.
- Inspect the refrigerant system with an ultraviolet (UV) lamp for traces of UV sensitive leak trace dye.
- If an obvious cause for an observed or reported concern is found, correct the cause (if possible) before proceeding to the next step.
- If the cause is not visually evident, verify the symptom and refer to the manufacturer approved diagnostic system.
SYMPTOM CHART
| Symptom | Possible Causes | Action |
|---|---|---|
| Air conditioning performance poor or inoperative | Refrigerant undercharged Refrigerant overcharged Thermostatic expansion valve faulty Receiver drier restricted Water in refrigerant | GO PINPOINT TEST A |
| Air conditioning operates briefly and then switches off | Electric cooling fan inoperative Air conditioning condenser airflow obstructed | Test the operation of the electric cooling fan Check the air conditioning condenser for external obstructions |
PINPOINT TEST A: PRELIMINARY TESTS
Pinpoint Test A
A1
PRELIMINARY TEST 1
- Close the valves on the air conditioning station
- Connect the air conditioning station to the vehicle charging ports
- Record the pressure values
Is a pressure registered on both gauges?
YES GO to Pinpoint Test «B»(ref-574736-S31184334332013091000000) .
NO GO to Pinpoint Test «D»(ref-574736-S34941782582013091000000) .
PINPOINT TEST B: FUNCTIONALITY TESTS
Pinpoint Test B
B1
FUNCTIONALITY TEST 1
- Close the valves on the air conditioning station
- Connect the air conditioning station to the vehicle charging ports
- Open all doors and the tailgate
- Start the engine
- Set the temperature to the lowest setting (all zones)
- Set the fan speed to maximum
- Set the recirculate switch to off
- Insert a temperature probe into the center air vent
- Raise engine speed to 1500rpm and maintain this speed for 5 minutes
- Record the temperature value
- Record the pressure values
Are the pressure readings stable and in the green 'normal' region of the gauge?
YES Air conditioning system operating normally
NO Air conditioning system fault present. GO to Pinpoint Test «C»(ref-574736-S37552956252013091000000) .
PINPOINT TEST C: GAUGE TESTS
Pinpoint Test C
C1
Did the gauges register a change in pressure when the air conditioning was switched on?
- Record the pressure values
Did the gauges register a change in pressure when the air conditioning was switched on?
YES GO to C 2 . → C2
NO Using the manufacturer approved diagnostic system, check the Automatic Temperature Control Module (ATCM) for related DTCs and refer to the relevant DTC index
C2
GAUGE TEST 2
- Record the pressure values
Are the pressure gauge readings fluctuating?
YES Moisture present in the air conditioning system. Recover the refrigerant. Install a new receiver drier. Refer to the relevant section of the service information and evacuate and recharge the air conditioning system. GO to Pinpoint Test «B»(ref-574736-S31184334332013091000000) .
NO GO to C 3 . → C3
C3
GAUGE TEST 3
- Record the pressure values
Are the pressure gauge readings too low?
C4
GAUGE TEST 4
- Using the manufacturer approved refrigerant leak detector, check for a refrigerant leak
Was a refrigerant leak detected?
YES Refer to the relevant section of the service information and recover the refrigerant. Repair as necessary. Evacuate and recharge the air conditioning system. GO to Pinpoint Test «B»(ref-574736-S31184334332013091000000) .
NO GO to C 5 . → C5
C5
GAUGE TEST 5
- Refer to the relevant section of the service information and recover the refrigerant
Was the weight of the recovered refrigerant less than specified for the air conditioning system?
YES Refer to the relevant section of the service information and evacuate and recharge the air conditioning system. GO to Pinpoint Test «B»(ref-574736-S31184334332013091000000) .
NO Install a new receiver drier. Refer to the relevant section of the service information and evacuate and recharge the air conditioning system. GO to Pinpoint Test «B»(ref-574736-S31184334332013091000000) .
C6
GAUGE TEST 6
- Record the pressure values
Are the pressure gauge readings too high?
YES GO to C 7 . → C7
NO Test inconclusive. GO to Pinpoint Test «B»(ref-574736-S31184334332013091000000) .
C7
GAUGE TEST 7
- Refer to the relevant section of the service information and recover the refrigerant
Was the weight of the recovered refrigerant more than specified for the air conditioning system?
YES Refer to the relevant section of the service information and evacuate and recharge the air conditioning system. GO to Pinpoint Test «B»(ref-574736-S31184334332013091000000) .
NO Install a new thermal expansion valve. Refer to the relevant section of the service information and evacuate and recharge the air conditioning system. GO to Pinpoint Test «B»(ref-574736-S31184334332013091000000) .
PINPOINT TEST D: NITROGEN LEAK TESTS
Pinpoint Test D
D1
NITROGEN LEAK TEST
- Charge the air conditioning system with nitrogen
- Isolate the nitrogen supply
- Monitor the pressure gauge and check for leaks
Has the source of the leak been identified?
YES Rectify the leak as necessary. Install a new receiver drier. Refer to the relevant section of the service information and evacuate and recharge the air conditioning system. GO to Pinpoint Test «B»(ref-574736-S31184334332013091000000) .
NO Refer to the relevant section of the service information and evacuate and recharge the air conditioning system. GO to Pinpoint Test «B»(ref-574736-S31184334332013091000000) .