Operation CHARM: Car repair manuals for everyone.

Performance Test - 72 Km/H (45 MPH) - HVAC System - Manual




1. Install a manifold gauge set to high and low side service ports and route hoses so that gauges can be read from inside vehicle with hood closed.
2. Start engine.
3. Depress A/C button so that indicator light is lit.
4. Select outside air - re-circulation button indicator light is off.
5. Install thermometer into right center outlet.
6. Set mode knob to I/P outlet position - full counter-clockwise.
7. Set temperature knob to full cold position - full counter-clockwise.
8. Set blower to third speed - M2.




9. Connect Tech 2 to diagnostic port and select "Engine Cooling Fan Control" menu. (See Tech 2 user guide for screen information.)
10. Verify engine is at thermostat control temperature - ECT is 188°F or more.
11. Drive vehicle 72 km/h (45 mph).
12. Record A/C system pressures and outlet temperature every minute for five minutes.
13. Release control of engine cooling fans.
14. Compare recorded values to system performance charts then continue down diagnostic flow chart.