Climate Control Pinpoint Test 5: Insufficient A/C Cooling

NOTE:

Make sure the heater control valve is functioning correctly before proceeding with this test. See PINPOINT TEST 2: INSUFFICIENT, ERRATIC OR NO HEAT for information regarding the heater control valve operation.

CLIMATE CONTROL PINPOINT TEST 5 CHART - INSUFFICIENT A/C COOLING

PINPOINT TEST 5		INSUFFICIENT A/C COOLING
STEP	INSPECTION		ACTION
1	CHECK THE CENTER A/C REGISTER DISCHARGE TEMPERATURE Carry out the refrigerant system tests. See A/C REFRIGERANT SYSTEM TESTS . Use the recorded data from the refrigerant system tests to plot a vertical line for ambient temperature and a horizontal line for center A/C register discharge temperature. Is the intersection of the two lines within the upper and lower limits?	Yes	The tests indicate that the system is functioning normally.
1		No	Go to step 2.
2	CHECK FOR NORMAL DISCHARGE PRESSURE Use the recorded data from the refrigerant system tests to plot a vertical line for ambient temperature and a horizontal line for compressor discharge (high) pressure. See A/C REFRIGERANT SYSTEM TESTS . Is the intersection of the two lines within the upper and lower limits?	Yes	Go to step 3.
2		No	Go to step 8.
3	EVALUATE THE SYSTEM LOW PRESSURE PERFORMANCE Use the recorded data from the refrigerant system tests to plot a vertical line for ambient temperature and a horizontal line for compressor suction (low) pressure. See A/C REFRIGERANT SYSTEM TESTS . Is the intersection of the two lines within the upper and lower limits?	Yes	Go to step 4.
3		No	Go to step 6.
4	CHECK FOR A SLOW OR CONTINUOUS RUN A/C CLUTCH CYCLE RATE Use the recorded data from the refrigerant system tests to plot a vertical line for ambient temperature and a horizontal line for total A/C clutch cycle time (time on plus time off) in seconds. See A/C REFRIGERANT SYSTEM TESTS . Is the intersection of the two lines above the upper limit?	Yes	Go to step 5.
4		No	Replace the A/C evaporator core due to a partially restricted or plugged condition. See EVAPORATOR CORE REMOVAL / INSTALLATION . Test the system for normal operation.
5	CHECK FOR A LONG OR CONTINUOUS A/C CLUTCH OFF TIME Use the recorded data from the refrigerant system tests to plot a vertical line for ambient temperature and a horizontal line for A/C clutch off time in seconds. See A/C REFRIGERANT SYSTEM TESTS . Is the intersection of the two lines above the upper limit?	Yes	Discharge and recover the system to remove excessive moisture or refrigerant oil. See A/C REFRIGERANT SYSTEM TESTS . Test the system for normal operation.
5		No	Go to step 7.
6	CHECK FOR A HIGH SUCTION PRESSURE See the data plot used to evaluate the system low pressure performance in Step 3. Is the intersection of the two lines above the upper limit?	Yes	Remove the A/C evaporator core orifice to replace missing or damaged (leaking) O-ring seals. See EVAPORATOR CORE REMOVAL / INSTALLATION . Test the system for normal operation.
6		No	Replace the A/C cycling switch due to a low cut-out condition. Test the system for normal operation.
7	CHECK THE AMBIENT TEMPERATURE See the data plot used to evaluate the system A/C clutch off time in Step 5. Is the ambient temperature above 26°C (80°F)?	Yes	This is normal operation for the refrigerant system in high humidity conditions.
7		No	Discharge and recover the system to correct an overcharge condition. See A/C REFRIGERANT SYSTEM TESTS . Test the system for normal operation.
8	CHECK FOR A HIGH DISCHARGE PRESSURE See the data plot used to evaluate the system high pressure performance in Step 2. Is the intersection of the two lines above the upper limit?	Yes	Go to step 9.
8		No	Go to step 11.
9	CHECK FOR A NORMAL LOW PRESSURE Use the recorded data from the refrigerant system tests to plot a vertical line for ambient temperature and a horizontal line for compressor suction (low) pressure. Is the intersection of the two lines within the upper and lower limits?	Yes	See COOLING SYSTEM INSPECTION - 2.3L to diagnose the engine cooling system. Test the system for normal operation. See COOLING SYSTEM INSPECTION - 4.0L to diagnose the engine cooling system. Test the system for normal operation.
9		No	Go to step 10.
10	CHECK FOR A NORMAL-TO-LOW SUCTION PRESSURE See the data plot used to evaluate the system low pressure performance in Step 9. Is the intersection of the two lines below the lower limit?	Yes	Replace the A/C evaporator core orifice due to a partially restricted or plugged condition. See EVAPORATOR CORE ORIFICE REMOVAL / INSTALLATION . Test the system for normal operation.
10		No	Inspect the A/C condenser core for a partially blocked or inadequate air flow. Test the system for normal operation.
11	CHECK FOR A NORMAL SUCTION PRESSURE Use the recorded data from the refrigerant system tests to plot a vertical line for ambient temperature and a horizontal line for compressor suction (low) pressure. Is the intersection of the two lines within the upper and lower limits?	Yes	Go to step 12.
11		No	Go to step 15.
12	CHECK FOR A SLOW A/C CLUTCH CYCLE RATE Use the recorded data from the refrigerant system tests to plot a vertical line for ambient temperature and a horizontal line for total A/C clutch cycle time (time on plus time off) in seconds. Is the intersection of the two lines above the upper limit?	Yes	Replace the manifold and tube assembly due to a partially restricted or plugged condition. See A/C MANIFOLD AND TUBE ASSEMBLY REMOVAL / INSTALLATION - 2.3L . See A/C MANIFOLD AND TUBE ASSEMBLY REMOVAL / INSTALLATION - 4.0L . Test the system for normal operation.
12		No	Go to step 13.
13	CHECK FOR A NORMAL A/C CLUTCH OFF TIME Use the recorded data from the refrigerant system tests to plot a vertical line for ambient temperature and a horizontal line for A/C clutch off time in seconds. Is the intersection of the two lines within the upper and lower limits?	Yes	Inspect the A/C evaporator core due to a low or restricted air flow. See EVAPORATOR CORE INSPECTION . Test the system for normal operation.
13		No	Go to step 14.
14	CHECK FOR A LONG A/C CLUTCH OFF TIME See the data plot used to evaluate the system A/C clutch off time performance in Step 13. Is the intersection of the two lines above the upper limit?	Yes	Replace the A/C condenser core due to a partially restricted or plugged condition. See A/C CORE REMOVAL / INSTALLATION . Test the system for normal operation.
14		No	Discharge and recover the system to correct a low refrigerant charge. See A/C REFRIGERANT SYSTEM TESTS . Test the system for normal operation.
15	CHECK THE A/C EVAPORATOR CORE ORIFICE Remove the A/C evaporator core orifice. See EVAPORATOR CORE ORIFICE REMOVAL / INSTALLATION . Is the A/C evaporator core orifice missing?	Yes	Replace the A/C evaporator core orifice. Test the system for normal operation.
15		No	Replace the A/C compressor due to low performance. See A/C COMPRESSOR REMOVAL / INSTALLATION - 2.3L . . See A/C COMPRESSOR REMOVAL / INSTALLATION - 4.0L . Test the system for normal operation.