GMC chervolet camaro 1999 Service Manual page 123

1-32 HVAC System - Manual
HVAC
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 Step2 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 StepB
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.lL ). -
-
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