Performance Test - Service Stall - HVAC System - Manual

IMPORTANT:
^ If ambient air temperature is lower than 0°C (32°F), A/C compressor will not be enabled.
^ 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 gauge set to high and low side service ports.
3. Start engine.
4. Depress A/C button so that indicator light is lit.
5. Depress re-circulation button so that indicator light is lit.
6. Install thermometer into right center outlet.
7. Set mode knob to I/P outlet position - full counter-clockwise.




8. Set temperature knob to full cold position - full counter-clockwise.
9. Set blower to third speed - M2.
10. Open both front doors and windows to stabilize interior air temperature with outside ambient temperature.
11. Connect Tech 2 to diagnostic port and select "Engine Cooling Fan Control" menu.
12. Verify engine is at thermostat control temperature - ECT is 188°F or more.
13. Increase engine speed to 2000 rpm and hold.
14. Record A/C system pressures and outlet temperature every minute for five minutes.
15. Release throttle to return engine to idle.
16. Release control of engine cooling fans.
17. Compare recorded values to system performance charts then continue down diagnostic flow chart.