Notice: The purity of the system refrigerant should be confirmed before any other diagnostics are begun. The RI-2002DS refrigerant identifier has the ability to identify R-12, R134a, R-22, potentially dangerous hydrocarbons, and non-condensable gases (NCG) such as air. If the A/C system contains anything less than 98 percent pure refrigerant, the refrigerant is considered contaminated and the temperature/pressure charts will not be valid. Contaminated refrigerant should not be recovered as it will contaminate the recovery machine and refrigerant supply tank. Air is not considered a contaminate as it can be purged.

1. Turn ON refrigerant identifier and let it reach operating temperature (3-5 minutes).
2. When display reads "HOSE," and with the vehicle turned OFF, attach the hose to the low side (suction) port and open service valves.
3. Press ENTER button.
4. The display will read GAS as a sample of refrigerant is taken and analyzed.
5. When analysis is complete, display will show, by percentage, the make-up of gases.

•	If refrigerant is less than 98 percent pure, the temperature/pressure charts will not be accurate for system diagnosis.

•	If refrigerant is pure but contains air, system should be recovered and recharged with virgin refrigerant before proceeding.

If an A/C system problem still exists after you have completed the preliminary inspects, more diagnostic tests must follow. These include manifold gage set readings. Follow the steps listed below for installing a manifold gage set.

Caution: Always wear goggles and wrap a clean cloth around fittings, valves, and connections when performing work that involves opening the refrigerant system.

Important: Inspect to make sure gages read zero before installing manifold gage set.

1. Close both hand valves of manifold gage set.
2. Connect low pressure (blue) gage hose to suction service port located on the suction pipe. Pull valve assembly collar up, place valve assembly over service port and release collar.
3. Open service valve.
4. Connect high pressure (red) gage hose to discharge service port located on the liquid line. Pull valve assembly collar up, place valve assembly over service port and release collar.
5. Open service valve.

Important: If ambient air temperature is lower than 0° C (32° F), A/C compressor will not be enabled.

Important: This test must be performed in a service stall environment that protects the vehicle from wind that could cause incorrect pressure/temperature readings.

1. Open hood and leave open during entire test.
2. Install a manifold gage set to high and low side service ports.
3. Disconnect vehicle thermal expansion valve (TXV) temperature sensor electrical connector and connect a temperature sensor that is exposed to ambient air.
4. Start engine and warm to operating temperature. Use scan tool to verify coolant temperature is being thermostatically controlled approx. 88°C (190°F).
5. Install thermometer into right center outlet.
6. Open both front doors and windows to stabilize interior air temperature with outside ambient temperature.
7. Press re-circulation button so that indicator light is lit.
8. Set temperature knob to full cold position.
9. Set mode knob to I/P outlet position.
10. Set blower to third speed.
11. Press A/C button.
12. Using Tech 2, command fan to HIGH speed.
13. Using accelerator pedal, increase engine speed to 2,000 RPM and hold.
14. Continue running until system pressures and outlet temperature stabilizes. Usually 4 to 8 minutes.
15. Record A/C system pressures and outlet temperature every minute for five minutes.
16. Exit out of the scan tool test and return engine to idle.
17. Release Tech 2 control of engine cooling fans.
18. Compare recorded values to system performance charts then continue down diagnostic flow chart.
19. When test is complete, re-connect the electrical connector for the vehicle TXV temperature sensor.