System Performance Test. Pontiac Grand Prix 1998

For 1990-2009 cars only

Makes 🢒 Pontiac 🢒 1998 🢒 Grand Prix 🢒 HVAC 🢒 HVAC Systems - Automatic 🢒 System Performance Test

Important: Be sure to record the relative humidity and ambient temperature conditions at the time of the test.

Park the vehicle inside or in the shade. The ambient temperature must be at least 16° C (60° F).
Open the windows to ventilate the interior.
Vent the engine exhaust.
Open the hood and install the high and low side pressure gauges.
Record the ambient temperature outside.
Record the relative humidity. Use a psychrometer or consult the local weather bureau.
Close the doors and windows.
Set the A/C control assembly to outside air mode with the blower speed set to high, the temperature to full cold and push the A/C button to turn on the A/C on.
Open the A/C air outlet deflectors.
Place a thermometer in the right center A/C outlet.
Place the transaxle in PARK and start the engine, stabilize engine at 2000 RPM.
Run the A/C system until the outlet air reaches the lowest temperature (about 3 minutes).
Record the outlet air temperature and the high side and low side pressures.
Turn the engine off and compare the readings with the upper limit data in the A/C Performance Table. Normally operating A/c system should not exceed levels shown.
If the readings exceed the table limits. Refer to VDOT A/C System Diagnosis .
If the readings are under the table limits, refer to Refrigerant System Checks .

Relative Humidity	Ambient Air Temperature		Maximum Low Side Pressure		Engine Speed	Maximum Right Center Air Outlet Temperature		Maximum High Side Pressure
%	°F	°C	PSI	kPa	RPM	°F	°C	PSI	kPa
20	70	21	37	255	2000	46	8	225	1551
	80	27	37	255		47	8	275	1896
	90	32	37	255		53	12	325	2241
	100	38	38	262		54	12	325	2241
30	70	21	37	255	2000	48	9	240	1655
	80	27	37	255		50	10	285	1965
	90	32	39	269		57	14	340	2344
	100	38	43	262		60	16	360	2482
40	70	21	37	255	2000	49	9	260	1793
	80	27	37	255		53	12	305	2103
	90	32	42	290		60	16	355	3137
	100	38	49	338		66	19	395	2724
50	70	21	37	255	2000	51	11	275	1896
	80	27	39	269		56	13	320	2206
	90	32	46	317		63	17	375	2586
	100	38	55	379		72	22	430	2965
60	70	21	37	255	2000	53	12	290	2000
	80	27	42	290		59	15	340	2344
	90	32	49	338		66	19	390	2689
	100	38	60	414		78	26	445	3068
70	70	21	37	255	2000	55	13	305	2103
	80	27	45	310		62	17	355	2448
	90	32	53	365		70	21	405	2792
80	70	21	41	283	2000	56	13	320	2206
	80	27	48	331		65	18	370	2551
	90	32	57	393		73	23	420	2896
90	70	21	45	310	2000	58	14	335	2310
90	80	27	52	359	2000	68	20	385	2655