2000 L Series HVAC Service Manual Update

The purpose of this bulletin is to update all the 2000 L-Series HVAC Service Manuals at your location.

Obtain all the 2000 L-Series HVAC Service Manuals at your location and update as indicated below.

1. Cross out page 21 and 22 with a marker or pen.
2. Remove this front page from staple in upper corner.
3. Insert revised procedure provided with this bulletin between pages 20 and 21.

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 the hood and leave it open during the entire test.
2. Install a manifold gage set to high and low side service ports.
3. Start engine.



4. Turn the A/C Off - A/C button indicator light Off.
5. Depress the re-circulation button so that the indicator light is On.
6. Install the thermometer into the right center outlet.
7. Set the mode knob to the I/P outlet position - full counter-clockwise.
8. Set the temperature knob to the full cold position - full counter-clockwise.
9. Set the blower to third speed -- M2.
10. Open both front doors and windows to stabilize the interior air temperature with outside ambient temperature.

Important:  A Tech 2 with version 19.007 or higher software is required to perform this test.

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

•	For L81 engines:

•	Select Fan Control 1 and press enter.

•	Command fan control On. Display should indicate fans are operating at MED.

•	Turn A/C On - A/C button indicator light On.

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

•	Using throttle, increase the engine speed to 2000 rpm and hold.

•	On L61 engines:

•	Select HVAC Performance special function and press enter. Display should indicate fans are operating at MED.

•	Turn the A/C On - A/C button indicator light On.

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

•	Using a Tech 2, increase the engine speed to 2000 rpm.

14. Record the A/C system pressures and outlet temperature every minute for 5 minutes.
15. Release the throttle to return the engine to idle.
16. Release Tech 2 control of engine cooling fans by exiting Tech 2 special function.
17. Compare recorded values to the system performance charts then continue down the diagnostic flow chart.

1. Install a manifold gage set to high and low side service ports and route hoses so that gages can be read from inside the vehicle with hood closed.
2. Start the engine.
3. Turn the A/C Off -- A/C button indicator light Off.
4. Select outside air -- re-circulation button indicator light is Off.
5. Install the thermometer into the right center outlet.



6. Set the mode knob to I/P outlet position -- full counter-clockwise.
7. Set the temperature knob to full cold position -- full counter-clockwise.
8. Set the blower to third speed -- M2.

Important:  A Tech 2 with version 19.007 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 operating 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:

•	Select Fan Control 1 and press enter.

•	Command fan control On. Display should indicate fans are operating at MED.

•	Turn A/C On -- A/C button indicator light On.

•	On L61 engines:

•	Select HVAC Performance special function and press enter. Display should indicate fans are operating at MED.

•	Turn A/C On -- A/C button indicator light On.

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

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