GMC chevrolet camaro 2000 Service Manual page 111

1-14 Heating, Ventilation and Air Conditioning
HVAC
Cooling Insufficient, A/C System - Pressure Zone B (cont'd)
Step Action Value(s) Yes
No
(
4
· is the pressure rise slow on both the low and high
-
side gages?
Go to Step 10 Go to Step 5
1. Turn the engine OFF.
2. Ensure that the compressor clutch is disengaged.
5
3. Attempt to rotate the compressor clutch driver
(NOT the pulley) by hand.
-
Does the compressor clutch driver (NOT the pulley) turn
freely by hand? Go to Step 10 Go to Step 6
1. Start the engine and allow the engine to idle.
2. Turn the A/C ON by depressing the A/C button on the
HV AC control.
6
3. Observe the low side pressure readings.
-
4. Elevate the engine speed to
between 3000-3800 RPM.
Is there a rapid rise in the low side pressure between
3000-3800 engine RPM? Go to Step 7 Go to Step 10
1. Elevate and maintain the engine speed at 2000 RPM.
2. The HVAC control still set to the following positions:
• The A/Con
• Temperature control to full cold
• Mode control knob to UPPER (IP outlets)
7
3. Set the blower switch to low
69-345 kPa
4. The vehicle windows and doors still closed.
(10-50 psi)
5. The vehicle hood still fully raised.
6. Both engine cooling fans operating.
(
7. Record the low side pressure reading.
Is the low side pressure reading within the specified
values? Go to Step 8 Go to Step 9
1. The engine still idling in PARK.
2. The HVAC control set to the following positions:
• A/C button to ON
O
Temperature control to full cold
• Mode control knob to UPPER (IP outlets)
• Blower switch to high
3. Elevate and maintain the engine speed at 2000 RPM.
8
4. Allow the low and high side pressure readings to
-
stabilize, if necessary.
(Stabilization usually requires 2-3 minutes.)
5. Record the low and high pressure readings.
6. Compare the low and high side pressures to the A/C
System Pressure - Zone Classification Graph above.
Do both the low and high side pressures fall within Zone B
on the chart (low side pressure still high and high side
pressure· still low)? Go to Step 10
Go to Step 11
1. Recover the refrigerant.
2. Replace the control valve.
Refer to Compressor Pressure Relief Valve Removal
9
(V5.- Conventional Mount) and Compressor Pressure
Relief Valve Install (V5 - Conventional Mount) or
-
-
Compressor Pressure Relief Valve Removal
(V7 - Direct Mount) and Compressor Pressure Relief
(
Valve Install (V7 - Direct Mount).
Is the repair complete?
Go to Step 12