Climate Control Pinpoint Test 3: A/C Does Not Operate/Does Not Operate Properly

NOTE:

Before carrying out the following test, diagnose any PCM DTCs.

NOTE:

Before carrying out the following test, check that the A/C system pressure is above 290 kPa (42 psi). If the pressure is below 290 kPa (42 psi), See A/C EVAPORATOR / CONDENSER CORE - ON-VEHICLE LEAK TEST .

NOTE:

The ambient temperature must be over 6°C (43°F).

CLIMATE CONTROL PINPOINT TEST 3 CHART - A/C DOES NOT OPERATE/DOES NOT OPERATE PROPERLY

PINPOINT TEST 3		AIR CONDITIONING (A/C) IS INOPERATIVE/DOES NOT OPERATE CORRECTLY
STEP	INSPECTION		ACTION
1	CHECK THE POWERTRAIN CONTROL MODULE (PCM) A/C PRESSURE SWITCH PID Key ON, Engine Running (KOER). Monitor the powertrain control module (PCM) A/C pressure switch PID. With the engine running, does the PCM A/C pressure switch PID read CLOSED?	Yes	Go to next step.
1		No	Go to step 4.
2	CHECK THE PCM A/C REQUEST PID WITH THE A/C ON Turn the function selector switch to the MAX A/C position. Monitor the PCM A/C request PID. Does the PCM A/C request PID read ON?	Yes	Go to next step.
2		No	Go to step 9.
3	CHECK THE PCM A/C CLUTCH RELAY PID WITH THE A/C ON Monitor the PCM A/C Clutch Relay PID. Does the PCM A/C clutch relay PID read ON?	Yes	Go to step 12.
3		No	Diagnose the PCM. See COMMUNICATIONS NETWORK .
4	4 CHECK CIRCUIT (B/Y) FOR VOLTAGE Key OFF. Disconnect the A/C compressor cycling switch connector 0740-201 Key ON, Engine OFF (KOEO). Measure the voltage between the A/C compressor cycling switch connector 0740-201 pin 4 (B/Y) and ground. Is the voltage greater than 10 volts?	Yes	Go to step 6.
4		No	Go to next step.
5	CHECK CIRCUIT (B/Y) FOR AN OPEN Key OFF. Disconnect the PCM connector 0140-175. Measure the resistance between A/C cycling switch 0740-201 pin 4, circuit (B/Y) and PCM 0140-175 pin 86, circuit (B/Y). Is the resistance less than 5 ohms?	Yes	Install a new PCM. See POWERTRAIN CONTROL MODULE (PCM) REMOVAL / INSTALLATION . Test the system for normal operation.
5		No	Repair circuit (B/Y) for an open. Test the system for normal operation.
6	CHECK CIRCUIT (R/Y) FOR GROUND Key OFF. Measure the resistance between A/C cycling switch 0740-201 pin 1, circuit (R/Y) and ground. Is the resistance less than 5 ohms?	Yes	Install a new A/C cycling switch. Test the system for normal operation.
6		No	Go to next step.
7	CHECK CIRCUIT (B/W) FOR AN OPEN Disconnect the A/C high pressure switch 0740-202. Measure the resistance between A/C high pressure switch 0740-202 pin 1, circuit (B/W) and ground. Is the resistance less than 5 ohms?	Yes	Go to next step.
7		No	Repair circuit (B/W). Test the system for normal operation.
8	CHECK CIRCUIT (R/Y) FOR AN OPEN Measure the resistance between A/C cycling switch 0740-201 pin 1, circuit (R/Y) and A/C high pressure switch 0740-202 pin 3, circuit (R/Y). Is the resistance less than 5 ohms?	Yes	Install a new A/C high pressure switch. Test the system for normal operation.
8		No	Repair circuit (R/Y) for an open. Test the system for normal operation.
9	CHECK CIRCUIT (V) FOR VOLTAGE Key OFF. Disconnect the PCM connector 0140-175. Key ON, Engine OFF (KOEO). Measure the voltage between PCM 0140-175 pin 41, circuit (V) and ground. Is the voltage greater than 10 volts?	Yes	Install a new PCM. Test the system for normal operation.
9		No	Go to next step.
10	CHECK CIRCUIT (GY/Y) Key OFF. Disconnect the function selector switch connector 0740-101. KOEO. Measure the voltage between function selector switch 0740-101 pin 1, circuit (GY/Y) and ground. Is the voltage greater than 10 volts?	Yes	Go to next step.
10		No	Verify smart junction box (SJB) fuse 27 (10A) is OK. If OK, Repair circuit (GY/Y). Test the system for normal operation.
11	CHECK CIRCUIT (V) FOR AN OPEN Key OFF. Measure the resistance between function selector switch 0740-101 pin 2, circuit (V) and PCM 0140-175 pin 41, circuit (V). Is the resistance less than 5 ohms?	Yes	Install a new function selector switch. Test the system for normal operation.
11		No	Repair circuit (V) for an open. Test the system for normal operation.
12	CHECK CIRCUIT (P/LB) FOR VOLTAGE Key OFF. Disconnect the A/C clutch relay Measure the voltage between A/C clutch relay socket pin 3, circuit (P/LB) and ground. Is the voltage greater than 10 volts?	Yes	Carry out the A/C clutch relay component test. See the SYSTEM WIRING DIAGRAMS article, Go to next step.
12		No	Verify power distribution box (PDB) fuse 25 (10A) is OK. If OK, Repair circuit (P/LB) for an open. Test the system for normal operation.
13	CHECK CIRCUIT (GY/W) FOR AN OPEN Key OFF. Disconnect the A/C clutch solenoid 0740-203. Measure the resistance between A/C clutch relay socket pin 5, circuit (GY/W) and A/C clutch solenoid 0740-203 pin 1, circuit (GY/W). Is the resistance less than 5 ohms?	Yes	Go to next step.
13		No	Repair circuit (GY/W) for an open. Test the system for normal operation.
14	CHECK FOR GROUND AT THE A/C COMPRESSOR CLUTCH FIELD COIL Measure the resistance between A/C clutch solenoid 0740-203, circuit (B) and ground. Is the resistance less than 5 ohms?	Yes	Go to next step.
14		No	Repair circuit (B) for an open. Test the system for normal operation.
15	CHECK THE A/C COMPRESSOR CLUTCH AIR GAP Key OFF. Measure the A/C compressor clutch air gap at 3 equally spaced locations between the clutch hub and the A/C compressor clutch pulley. Is the compressor clutch air gap greater than 0.75 mm (0.030 inch)?	Yes	Adjust the A/C compressor clutch air gap. See A/C COMPRESSOR MAGNETIC CLUTCH ADJUSTMENT . Test the system for normal operation.
15		No	Install a new A/C compressor clutch field coil. See A/C COMPRESSOR MAGNETIC CLUTCH REMOVAL / INSTALLATION . Test the system for normal operation.