Performance Test @ 72 Km/h (45 Mph)

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. Turn A/C Off - A/C button indicator light Off.
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.

IMPORTANT: A Tech 2 with version 19.005 or higher software is required to perform this test.

9. Connect Tech 2 to data link connector (DLC).
10. Using the Tech 2, verify engine is operative at thermostat control temperature - ECT is 188°F or greater.
11. Use the appropriate Tech 2 special function to set engine cooling fan speed to medium.

^ For L81 engines.
a. Select Fan Control 1 and press enter.
b. Command fan control On. Display should indicate fans are operating at MED.
c. Turn A/C On - A/C button indicator light On.

^ On L61 engines:
a. Select HVAC Performance special function and press enter. Display should indicate fans arc operating at MED.
b. Turn A/C On - A/C button indicator light On.

IMPORTANT: Allow A/C system pressures to stabilize before beginning test.

12. Drive vehicle at 72 km/h (45 mph).
13. Record A/C system pressures and outlet temperature every minute for 5 minutes.
14. Release Tech 2 control of engine cooling fans.
15. Compare recorded values to system performance charts then continue down diagnostic flow chart.