System Performance Test

Pressure-Temperature Relationship Chart:

A/C System Performance Table:

Tool Required:
J 21213-A Four Jack-Dual Range Temperature Tester or Equivalent

1. Park the vehicle inside or in a shaded area.
2. Open doors or windows to ventilate the interior.
3. Vent the engine exhaust, if necessary.
4. Open the hood and install high and low side pressure gages. Route lines over the rear hood seal and tape the gages to the windshield for viewing.
5. Close the hood.
6. Record the ambient temperature at the vehicle.
7. Record the relative humidity. Use a psychrometer or consult the local weather bureau.

Important

- Make sure to record the relative humidity and ambient temperature conditions at the time of the test.

8. Close the doors or windows.
9. Set the mode control to "NORM A/C," blower control on "HIGH," and temperature control on full "Cold."
10. Open the air conditioning outlets.
11. install J 21213-A or equivalent into the right center air conditioning outlet.
12. Place the transmission in "PARK" or "NEUTRAL."
13. Start the engine, stabilize engine speed at 2000 RPM, and start the timer.
14. Run the air conditioning system until the outlet air reaches the lowest temperature (about 3 minutes).
15. Record the outlet air temperature and high-side and low-side pressures.
16. Turn the engine off and compare the readings. Normally operating air conditioning systems should not exceed the levels shown on the Pressure Temperature Relationship and System Performance Test tables.