NO.27 A/C DOES NOT WORK SUFFICIENTLY [MZR-CD 2.2]

NO.27 A/C DOES NOT WORK SUFFICIENTLY [MZR-CD 2.2]SM2444563

id0103f3843000

27	A/C DOES NOT WORK SUFFICIENTLY
DESCRIPTION	• A/C compressor magnetic clutch does not engage when the A/C switch is turned on.
POSSIBLE CAUSE	• PCM, climate control unit, instrument cluster or multi information display DTC is stored • Refrigerant pressure sensor 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 • Instrument cluster malfunction (Does not receive A/C request signal from climate control unit or transmit it to PCM) (Full-auto air conditioner) • Multi information display malfunction • 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 J and BCM terminal 3L (Manual air conditioner) • BCM malfunction (Does not receive A/C request signal from climate control unit or transmit it to PCM) (Manual air conditioner) • 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 1BX • 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 • PCM malfunction

A/C DOES NOT WORK SUFFICIENTLY

DESCRIPTION

• A/C compressor magnetic clutch does not engage when the A/C switch is turned on.

POSSIBLE CAUSE

• PCM, climate control unit, instrument cluster or multi information display DTC is stored

• Refrigerant pressure sensor 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

• Instrument cluster malfunction (Does not receive A/C request signal from climate control unit or transmit it to PCM) (Full-auto air conditioner)

• Multi information display malfunction

• 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 J and BCM terminal 3L (Manual air conditioner)

• BCM malfunction (Does not receive A/C request signal from climate control unit or transmit it to PCM) (Manual air conditioner)

• 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 1BX

• 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

• PCM malfunction

Diagnostic Procedure

STEP	INSPECTION	RESULTS	ACTION
1	Switch the ignition ON (Engine off). Retrieve PCM, BCM, instrument cluster and climate control unit DTCs. (See ON-BOARD DIAGNOSTIC TEST [MZR-CD 2.2].) (See DTC INSPECTION [BCM].) (See DTC INSPECTION [INSTRUMENT CLUSTER].) (See DTC DISPLAY.) Are there any DTCs displayed?	Yes	Go to the applicable DTC inspection. (See DTC TABLE [MZR-CD 2.2].) (See DTC TABLE [BCM].) (See DTC TABLE [MULTI INFORMATION DISPLAY].) (See DTC TABLE.)
1		No	Go to the next step.
2	Access the PCM PID ACCS using the M-MDS. (See ON-BOARD DIAGNOSTIC TEST [MZR-CD 2.2].) Start the engine and idle it. Turn the ACCS PID to ON from OFF using the M-MDS simulation function. Is the A/C magnetic clutch engaged?	Yes	Full-auto air conditioner: • Go to Step 6. Manual air conditioner: • Go to the next step.
2		No	Go to Step 15.
3	Access the BCM PID ACSW using the M-MDS. (See PID/DATA MONITOR INSPECTION [BCM].) Monitor the ACSW PID while turning on and off the air conditioner by switching the control panel. Is the PID normal? (See PID/DATA MONITOR TABLE [BCM].)	Yes	Go to Step 6.
3		No	Go to the next step.
4	Remove the climate control unit. (See CLIMATE CONTROL UNIT REMOVAL [MANUAL AIR CONDITIONER].) Reconnect the climate control unit connector. Start the engine and idle it. Measure the climate control unit terminal J (24-pin) voltage while turning on and off the air conditioner by control panel. Is the voltage change in specified according to control panel switching? (See CLIMATE CONTROL UNIT REMOVAL [MANUAL AIR CONDITIONER].)	Yes	Go to the next step.
4		No	Go to Step 6.
5	Inspect for open or short circuit between climate control unit terminal J (24-pin) and BCM terminal 3L. Is there any open or short circuit detected?	Yes	Repair or replace the suspected wiring harness.
5		No	Replace the BCM (BCM can not receive the A/C request signal from climate control unit or transmit it to PCM). (See BODY CONTROL MODULE (BCM) REMOVAL/INSTALLATION.)
6	Start the engine and idle it. Measure the voltage of the following terminals: • Full-auto air conditioner: ― Climate control unit terminal 1F • Manual air conditioner: ― Climate control unit terminal I Is the voltage normal? (See CLIMATE CONTROL UNIT INSPECTION [FULL-AUTO AIR CONDITIONER].) (See CLIMATE CONTROL UNIT INSTALLATION [MANUAL AIR CONDITIONER].)	Yes	Go to Step 9.
6		No	Go to the next step.
7	Switch the ignition ON (Engine off). Measure the voltage of the following terminals: • Full-auto air conditioner: ― Climate control unit terminal 1C • Manual air conditioner: ― Climate control unit terminal K Is the voltage normal? (See CLIMATE CONTROL UNIT INSPECTION [FULL-AUTO AIR CONDITIONER].) (See CLIMATE CONTROL UNIT INSTALLATION [MANUAL AIR CONDITIONER].)	Yes	Go to the next step.
7		No	Replace the climate control unit. (See CLIMATE CONTROL UNIT REMOVAL/INSTALLATION [FULL-AUTO AIR CONDITIONER].) (See CLIMATE CONTROL UNIT REMOVAL [MANUAL AIR CONDITIONER].) (See CLIMATE CONTROL UNIT INSTALLATION [MANUAL AIR CONDITIONER].)
8	Inspect for open or short circuit between following climate control unit terminal (24-pin) and evaporator temperature sensor terminal: • Full-auto air conditioner: ― Between climate control unit terminal 1C and evaporator temperature sensor terminal A ― Between climate control unit terminal 1F and evaporator temperature sensor terminal B • Manual air conditioner: ― Between climate control unit terminal K and evaporator temperature sensor terminal A ― Between climate control unit terminal I and evaporator temperature sensor terminal B Is there any open or short circuit detected?	Yes	Repair or replace the suspected wiring harness.
8		No	Replace the evaporator temperature sensor. (See EVAPORATOR TEMPERATURE SENSOR REMOVAL/INSTALLATION [FULL-AUTO AIR CONDITIONER].) (See EVAPORATOR TEMPERATURE SENSOR REMOVAL/INSTALLATION [MANUAL AIR CONDITIONER].)
9	Inspect the refrigerant pressure switch. (See REFRIGERANT PRESSURE SWITCH INSPECTION [FULL-AUTO AIR CONDITIONER].) (See REFRIGERANT PRESSURE SENSOR INSPECTION [MANUAL AIR CONDITIONER].) Is the refrigerant pressure sensor/refrigerant pressure switch normal?	Yes	Full-auto air conditioner: • Go to Step 13. Manual air conditioner: • Replace the climate control unit (A/C switch malfunction or climate control unit can not determine A/C request or transmit it to BCM). (See CLIMATE CONTROL UNIT REMOVAL [MANUAL AIR CONDITIONER].) (See CLIMATE CONTROL UNIT INSTALLATION [MANUAL AIR CONDITIONER].)
9		No	Go to the next step.
10	Inspect the refrigerant pressure. (See REFRIGERANT PRESSURE CHECK.) Is the refrigerant pressure normal?	Yes	Go to the next step. (Manual air conditioner)/Go to Step 12. (Full-auto air conditioner)
10		No	Repair or replace the malfunctioning part according to the inspection results.
11	Switch the ignition ON (Engine off). Measure the voltage of the following terminals: • Climate control unit terminal N Is the voltage normal? (See CLIMATE CONTROL UNIT INSTALLATION [MANUAL AIR CONDITIONER].)	Yes	Go to the next step.
11		No	Replace the climate control unit. (See CLIMATE CONTROL UNIT REMOVAL [MANUAL AIR CONDITIONER].) (See CLIMATE CONTROL UNIT INSTALLATION [MANUAL AIR CONDITIONER].)
12	Inspect for open or short circuit between following climate control unit terminal (24-pin) and refrigerant pressure sensor terminal: • Full-auto air conditioner: ― Between refrigerant pressure switch terminal B and PCM terminal 1AF ― Between refrigerant pressure switch terminal D and body ground • Manual air conditioner: ― Between climate control unit terminal E and refrigerant pressure sensor terminal A ― Between climate control unit terminal N and refrigerant pressure sensor terminal B ― Between climate control unit terminal K and refrigerant pressure sensor terminal C Is there any open or short circuit detected?	Yes	Repair or replace the suspected wiring harness.
12		No	Replace the refrigerant pressure sensor/refrigerant pressure switch. (See REFRIGERANT PRESSURE SENSOR REMOVAL/INSTALLATION [FULL-AUTO AIR CONDITIONER].) (See REFRIGERANT PRESSURE SENSOR REMOVAL/INSTALLATION [MANUAL AIR CONDITIONER].)
13	Verify the multi information display indication of A/C system while turning on and off the air conditioner by switching the control panel. Does the multi information display indicate properly?	Yes	Replace the instrument cluster (Instrument cluster can not receive the A/C request signal from climate control unit or transmit it to PCM). (See INSTRUMENT CLUSTER REMOVAL/INSTALLATION.)
13		No	Go to the next step.
14	Inspect the multi information display. (See MULTI INFORMATION DISPLAY INPUT/OUTPUT CHECK MODE.) Is the multi information display normal?	Yes	Replace the climate control unit (A/C switch malfunction or climate control unit can not determine A/C request or transmit it to instrument cluster). (See CLIMATE CONTROL UNIT REMOVAL/INSTALLATION [FULL-AUTO AIR CONDITIONER].)
14		No	Repair or replace the malfunctioning part according to the inspection results.
15	Start the engine and idle it. Verify that the A/C relay operation sound is heard while PCM PID ACCS to ON from OFF using the M-MDS simulation function. Is the A/C operation sound heard?	Yes	Go to the next step.
15		No	Go to Step 17.
16	Inspect the A/C compressor magnetic clutch. (See MAGNETIC CLUTCH INSPECTION [FULL-AUTO AIR CONDITIONER].) (See MAGNETIC CLUTCH INSPECTION [MANUAL AIR CONDITIONER].) Is the magnetic clutch normal?	Yes	Inspect and repair for open or short circuit between battery positive terminal and A/C compressor terminal A.
16		No	Replace the magnetic clutch. (See MAGNETIC CLUTCH DISASSEMBLY/ASSEMBLY [FULL-AUTO AIR CONDITIONER].) (See MAGNETIC CLUTCH DISASSEMBLY/ASSEMBLY [MANUAL AIR CONDITIONER].)
17	Inspect the A/C relay. (See RELAY INSPECTION [MZR-CD 2.2].) Is the A/C relay normal?	Yes	Go to the next step.
17		No	Replace the A/C relay.
18	Remove the A/C relay. Start the engine and idle it. Measure the A/C relay terminal (fuse box side connector) while PCM PID ACCS to ON from OFF using the M-MDS simulation function. Is the voltage below 1.0 V?	Yes	Inspect and repair for open circuit between ignition switch terminal B and A/C relay terminal E.
18		No	Inspect and repair for open or short to power supply circuit between PCM terminal 1BX and A/C relay terminal A.
19	Verify test results. • If normal, return to the diagnostic index to service any additional symptoms. (See SYMPTOM DIAGNOSTIC INDEX [MZR-CD 2.2].) • If the malfunction remains, inspect the related Service Information and perform repair or diagnosis. ― If the vehicle is repaired, troubleshooting completed. ― If the vehicle is not repaired or additional diagnostic information is not available, reprogram the PCM if later calibration is available.