GMC Chevrolet Camaro 1998 Service Manual page 139

HVAC HVAC System - Manual 1-29
Low Side Pressure
Step Action Value(s) Yes No
)
DEFINITION: Left area diagnosis and service.
Were you sent here from the VDOT System Performance
Go to the VDOT
1 Diagnostic Table?
-
System
Go to Step 2
Performance
With the engine running, connect high and low side
2
pressure gages.
207 kPa
Are the high and low side pressures equal to the
(30 psi)
specified value? Go to Step 3 Go to Step 8
1. Close all the vehicle doors and windows.
2. Run the engine at 2000 rpm.
3. Set the temperature control to full cold.
3
4. Set the blower motor speed to high.
207 kPa
(30 psi)
-
5. Cycle the mode knob from vent to A/C every
20 seconds for 3 minutes.
Are the high and low side pressures equal to the
specified value? Go to Step 4
Inspect for the following conditions:
• A slow rise in pressure in both the low and high
4
side gages.
• The compressor suction line is warm.
-
• The discharge line is very hot.
Do all of the above conditions exist?
Go to Step 5 Go to Step 6
Replace the compressor. Refer to Compressor
5
Replacement (3.BL)
or
Compressor Replacement (5. 7L). -
-
Is the repair complete? System OK
Turn the engine OFF.
6
With the compressor clutch disengaged, does the
compressor clutch driver (not the pulley) turn freely
-
by hand? Go to Step 5 Go to Step 7
Inspect the low side pressure.
7
Is there a rapid rise in the low side pressure with the
2000-2800 rpm
Go to the
engine rpm between the value(s) shown? Control Valve Go to Step 5
8
Inspect the low side pressure.
172-241 kPa
Go to the
Is the low side pressure within the specified values?
(27-38 psi)
Go to Step 9
Control Valve
9
Feel the liquid line before the expansion (orifice) tube.
-
Is the liquid cold?
Go to Step 10
Go to Step 12
Inspect the liquid line for a restriction before the expansion
10
(orifice) tube.
-
Go to the
Is there a restriction in the liquid line before the expansion
System
(orifice) tube?
Go to Step 11 .
Performance
Repair the restriction or replace the liquid line before the
Go to the
11
expansion (orifice) tube. -
System
Is the repair complete? System OK Performance
12
Add 0.40 kg ( 14 oz) of refrigerant to the system:
-
Does the cooling improve?
Go to Step 13 Go to Step 15
13
Perform a leak test. Refer to
Leak Testing.
-
Is there a leak?
Go to Step 14
System OK
1. Repair the leak.
14
2. Recover and recharge the A/C system. Refer to
- -
Refrigerant Recovery and Recharging.
)
Is the repair complete? System OK