No. 23 A/C Does Not Work Sufficiently

23	A/C DOES NOT WORK SUFFICIENTLY
DESCRIPTION	The A/C compressor magnetic clutch does not engage when the A/C switch is turned on.
POSSIBLE CAUSE	PCM DTC is stored Refrigerant pressure switch malfunction Improper refrigerant charging amount Seized A/C compressor Evaporator temperature sensor malfunction Open or short circuit in wiring harness between evaporator temperature sensor and climate control unit Climate control unit malfunction (A/C switch malfunction or climate control unit does not determine A/C request or transmit the A/C request signal) Open or short circuit in wiring harness between climate control unit terminal K and PCM terminal 1 AU Open circuit in wiring harness between climate control unit terminal H and body ground. A/C compressor malfunction Open circuit in wiring harness between A/C compressor terminal A and body ground A/C relay malfunction Open circuit in wiring harness between A/C relay and PCM terminal 1I Open circuit in wiring harness between ignition switch (IG2) and A/C relay Open circuit in wiring harness between battery positive terminal and A/C relay Open circuit in wiring harness between A/C relay and A/C magnetic clutch

DIAGNOSTIC PROCEDURE

STEP	INSPECTION	RESULTS	ACTION
1	Turn the ignition switch to the ON position (Engine off). Retrieve any DTCs. Are there any DTCs displayed?	Yes	Go to the appropriate DTC inspection. (See DTC TABLE ).
1		No	Go to the next step.
2	Access PCM PID ACCS using the M-MDS. Start the engine and idle it. Turn the PID ACCS to ON from OFF using the M-MDS simulation function. Is the A/C magnetic clutch engaged?	Yes	Go to the next step.
2		No	Go to Step 10.
3	Disconnect the refrigerant pressure switch connector. Connect the jumper wire between refrigerant pressure switch wiring harness-side connector terminals A and D. Start the engine and idle it. Access PCM PID AC_REQ using the M-MDS. Monitor the PID AC_REQ while turning on and off by switching the control panel. Does the PID change according to air control panel switching? (See PCM INSPECTION ).	Yes	Go to Step 5.
3		No	Go to the next step.
4	Connect the jumper wire between refrigerant pressure switch wiring harness-side connector terminals A and body ground. Start the engine and idle it. Access PCM PID AC_REQ using the M-MDS. Monitor the PID AC_REQ. Is the PID indicated on? (See PCM INSPECTION ).	Yes	Go to the next step.
4		No	Repair for open circuit between refrigerant pressure switch terminal A and PCM terminal 1AU.
5	Inspect refrigerant pressure switch. (See REFRIGERANT PRESSURE SWITCH INSPECTION [FULL-AUTO AIR CONDITIONER] ). (See REFRIGERANT PRESSURE SWITCH INSPECTION (MANUAL AIR CONDITIONER) ). Is the refrigerant pressure switch normal?	Yes	Inspect for following and repair or replace if necessary. Refrigerant charging amount A/C compressor for seizure
5		No	Replace the refrigerant pressure switch. (See REFRIGERANT PRESSURE SWITCH REMOVAL/INSTALLATION [FULL-AUTO AIR CONDITIONER] ). (See REFRIGERANT PRESSURE SWITCH REMOVAL/INSTALLATION (MANUAL AIR CONDITIONER) ).
6	Inspect for open or short circuit between climate control unit terminal K and refrigerant pressure switch terminal D. Is there any malfunction?	Yes	Repair for open or short circuit.
6		No	Go to the next step.
7	Turn the ignition to off. Disconnect the climate control unit connector. Verify continuity between climate control unit wiring harness-side connector terminal H and body ground. Is there any continuity?	Yes	Go to the next step.
7		No	Repair for open circuit.
8	Reconnect the climate control unit connector. Measure the voltage at climate control unit terminal M. Is the voltage within the specified? (See CLIMATE CONTROL UNIT INSPECTION [FULL-AUTO AIR CONDITIONER] ). (See CLIMATE CONTROL UNIT INSPECTION (MANUAL AIR CONDITIONER) ).	Yes	Go to the next step.
8		No	Replace the climate control unit. (A/C switch malfunction or climate control unit does not determine A/C request or transmit the A/C request signal) (See CLIMATE CONTROL UNIT REMOVAL/INSTALLATION [FULL-AUTO AIR CONDITIONER] ). (See CLIMATE CONTROL UNIT REMOVAL/INSTALLATION (MANUAL AIR CONDITIONER) ).
9	Inspect the evaporator temperature sensor. (See EVAPORATOR TEMPERATURE SENSOR INSPECTION [FULL-AUTO AIR CONDITIONER] ). (See EVAPORATOR TEMPERATURE SENSOR INSPECTION (MANUAL AIR CONDITIONER) ). Is the evaporator temperature sensor normal?	Yes	Inspect and repair for open or short circuit between evaporator temperature sensor and climate control unit.
9		No	Replace the evaporator temperature sensor. (See REFRIGERANT PRESSURE SWITCH REMOVAL/INSTALLATION [FULL-AUTO AIR CONDITIONER] ). (See EVAPORATOR TEMPERATURE SENSOR REMOVAL/INSTALLATION (MANUAL AIR CONDITIONER) ).
10	Start the engine and kite it. Turn the PID ACCS to ON from OFF using the M-MDS simulation function. Measure the voltage between A/C compressor terminal B and body ground. Is the voltage specified? Specification 10.5 V or more	Yes	Go to the next step.
10		No	Go to Step 15.
11	Verify continuity between A/C compressor terminal A and body ground. Is there any continuity?	Yes	Go to the next step.
11		No	Repair or replace for open circuit and/or poor contact ground points.
12	Inspect the A/C relay. (See RELAY INSPECTION ). Is the A/C relay normal?	Yes	Go to the next step.
12		No	Replace the A/C relay.
13	Turn the ignition off. Disconnect the A/C relay and PCM connectors. Verify continuity between A/C relay and PCM terminal 1I at wiring harness-side connector. Is there any continuity?	Yes	Inspect for open circuit in followings: Between ignition switch (IG2) and A/C relay Between battery positive post and A/C relay Between A/C relay and A/C magnetic clutch
13		No	Repair or replace for open circuit.
14	Verify test results. If normal, return to diagnostic index to service any additional symptoms. (See SYMPTOM DIAGNOSTIC INDEX ). If malfunction remains, inspect related Service Bulletins and/or On-line Repair Information and perform repair or diagnosis. If vehicle is repaired, troubleshooting completed. If vehicle is not repaired or additional diagnostic information is not available, replace the PCM. (See PCM REMOVAL/INSTALLATION ).