NO.23 A/C DOES NOT WORK SUFFICIENTLY [MZR 2.0, MZR 2.5]

id0103e1802900

23

A/C DOES NOT WORK SUFFICIENTLY

DESCRIPTION

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

POSSIBLE CAUSE

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

•  Improper refrigerant charging amount

•  Refrigerant pressure sensor malfunction

•  Evaporator temperature sensor malfunction

•  Open or short circuit in wiring harness between evaporator temperature sensor and climate control unit (Full-auto air conditioner)

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

•  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)

•  Communication error between instrument cluster and climate control unit

•  Communication error between PCM and instrument cluster

•  Poor ground of magnetic clutch

•  Open or short circuit in wiring harness between climate control unit terminal 2P and instrument cluster terminal 2I (Manual air conditioner)

•  Open the magnetic clutch

•  A/C relay is stuck open

•  Seized A/C compressor

•  Open circuit in wiring harness between A/C relay and PCM terminal 1I

•  Open circuit in wiring harness between A/C relay and ignition switch (IG2) (vehicles without advanced keyless entry and push button start system)

•  Open circuit in wiring harness between A/C relay and IG2 relay (vehicles with advanced keyless entry and push button start system)

•  Open circuit in wiring harness between A/C relay and battery positive terminal

•  Open circuit in wiring harness between A/C relay and magnetic clutch

•  PCM malfunction

23	A/C DOES NOT WORK SUFFICIENTLY
DESCRIPTION	• The A/C compressor magnetic clutch does not engage when the A/C is turned on.
POSSIBLE CAUSE	• PCM, climate control unit, instrument cluster or multi information display DTC is stored. • Improper refrigerant charging amount • Refrigerant pressure sensor malfunction • Evaporator temperature sensor malfunction • Open or short circuit in wiring harness between evaporator temperature sensor and climate control unit (Full-auto air conditioner) • Instrument cluster malfunction (Does not receive A/C request signal from climate control unit or transmit it to PCM) • 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) • Communication error between instrument cluster and climate control unit • Communication error between PCM and instrument cluster • Poor ground of magnetic clutch • Open or short circuit in wiring harness between climate control unit terminal 2P and instrument cluster terminal 2I (Manual air conditioner) • Open the magnetic clutch • A/C relay is stuck open • Seized A/C compressor • Open circuit in wiring harness between A/C relay and PCM terminal 1I • Open circuit in wiring harness between A/C relay and ignition switch (IG2) (vehicles without advanced keyless entry and push button start system) • Open circuit in wiring harness between A/C relay and IG2 relay (vehicles with advanced keyless entry and push button start system) • Open circuit in wiring harness between A/C relay and battery positive terminal • Open circuit in wiring harness between A/C relay and magnetic clutch • PCM malfunction

Diagnostic procedure

STEP	INSPECTION	RESULTS	ACTION
1	Retrieve the PCM, instrument cluster, multi information display and climate control unit DTCs. (See ON-BOARD DIAGNOSTIC TEST [MZR 2.0, MZR 2.5].) (See DTC INSPECTION [INSTRUMENT CLUSTER].) (See DTC INSPECTION [INFORMATION DISPLAY/MULTI INFORMATION DISPLAY].) (See DTC DISPLAY [FULL-AUTO AIR CONDITIONER].) Are any DTCs present?	Yes	Go to the appropriate DTC inspection. (See DTC TABLE [MZR 2.0, MZR 2.5].) (See DTC TABLE [INSTRUMENT CLUSTER].) (See DTC TABLE [INFORMATION DISPLAY/MULTI INFORMATION DISPLAY].) (See DTC TABLE [FULL-AUTO AIR CONDITIONER].)
1		No	Go to the next step.
2	Access the ACCS PID using the M-MDS. (See ON-BOARD DIAGNOSTIC TEST [MZR 2.0, MZR 2.5].) Start the engine and idle it. Turn the ACCS PID to ON from OFF using the M-MDS simulation function. Is the magnetic clutch engaged?	Yes	Manual air conditioner: • Go to Step 4. Full-auto air conditioner: • Go to the next step.
2		No	Go to Step 13.
3	Access the climate control unit PID AC_PRES using the M-MDS. (See PID/DATA MONITOR DISPLAY [FULL-AUTO AIR CONDITIONER].) Monitor the climate control unit AC_PRES PID while turning on and off the air conditioner by switching the control panel. Is the AC_PRES PID value normal? (See PID/DATA MONITOR TABLE [FULL-AUTO AIR CONDITIONER].)	Yes	Go to Step 6.
3		No	Go to Step 5.
4	Remove the climate control unit. (See CLIMATE CONTROL UNIT REMOVAL/INSTALLATION [MANUAL AIR CONDITIONER].) Reconnect the climate control unit connector. Measure the voltage at the climate control unit terminal 1H (wiring harness-side). Is the voltage normal? (See CLIMATE CONTROL UNIT INSPECTION [MANUAL AIR CONDITIONER].)	Yes	Go to Step 7.
4		No	Go to the next step.
5	Inspect the refrigerant pressure sensor. (See REFRIGERANT PRESSURE SENSOR INSPECTION [MANUAL AIR CONDITIONER].) (See REFRIGERANT PRESSURE SENSOR INSPECTION [FULL-AUTO AIR CONDITIONER].) Is there any malfunction?	Yes	Replace the refrigerant pressure sensor. (See REFRIGERANT PRESSURE SENSOR REMOVAL/INSTALLATION [MANUAL AIR CONDITIONER].) (See REFRIGERANT PRESSURE SENSOR REMOVAL/INSTALLATION [FULL-AUTO AIR CONDITIONER].)
5		No	Inspect the following: • Refrigerant charging amount • A/C compressor for seizure Repair or replace the malfunctioning part according to the inspection result.
6	Access the climate control unit PID EVAP_TEMP using the M-MDS. (See PID/DATA MONITOR DISPLAY [FULL-AUTO AIR CONDITIONER].) Monitor the climate control unit PID EVAP_TEMP while turning on and off the air conditioner by switching the control panel. Is the EVAP_TEMP PID value normal? (See PID/DATA MONITOR TABLE [FULL-AUTO AIR CONDITIONER].)	Yes	Go to Step 9.
6		No	Go to Step 8.
7	Remove the climate control unit. (See CLIMATE CONTROL UNIT REMOVAL/INSTALLATION [MANUAL AIR CONDITIONER].) Reconnect the climate control unit connector. Measure the voltage at the climate control unit terminal 1C (wiring harness-side). Is the voltage normal? (See CLIMATE CONTROL UNIT INSPECTION [MANUAL AIR CONDITIONER].)	Yes	Go to Step 11.
7		No	Go to the next step.
8	Inspect the evaporator temperature sensor. (See EVAPORATOR TEMPERATURE SENSOR INSPECTION [MANUAL AIR CONDITIONER].) (See EVAPORATOR TEMPERATURE SENSOR INSPECTION [FULL-AUTO AIR CONDITIONER].) Is there any malfunction?	Yes	Replace the evaporator temperature sensor. (See EVAPORATOR TEMPERATURE SENSOR REMOVAL/INSTALLATION [MANUAL AIR CONDITIONER].) (See EVAPORATOR TEMPERATURE SENSOR REMOVAL/INSTALLATION [FULL-AUTO AIR CONDITIONER].)
8		No	Inspect for open or short circuit between evaporator temperature sensor and climate control unit. Repair or replace the suspected wiring harness.
9	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 does not receive the A/C request signal from climate control unit or transmit it to PCM.) (See INSTRUMENT CLUSTER REMOVAL/INSTALLATION.)
9		No	Go to the next step.
10	Inspect the multi information display. (See MULTI INFORMATION DISPLAY INSPECTION.) Is there any malfunction?	Yes	Replace the multi information display. (See MULTI INFORMATION DISPLAY REMOVAL/INSTALLATION.)
10		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].)
11	Remove the climate control unit. (See CLIMATE CONTROL UNIT REMOVAL/INSTALLATION [MANUAL AIR CONDITIONER].) Reconnect the climate control unit connector. Start the engine and idle it. Measure the voltage at the climate control unit terminal 2P (wiring harness-side) while turning on and off the air conditioner by switching the control panel. Is the voltage change in specified according to air control panel switching? (See CLIMATE CONTROL UNIT INSPECTION [MANUAL AIR CONDITIONER].)	Yes	Replace the instrument cluster (instrument cluster does not receive A/C request signal from climate control unit or transmit it to PCM). (See INSTRUMENT CLUSTER REMOVAL/INSTALLATION.)
11		No	Go to the next step.
12	Inspect for open or short circuit between climate control unit terminal 2P (wiring harness-side) and instrument cluster terminal 2I (wiring harness-side). Is there any malfunction?	Yes	Repair or replace the suspected wiring harness.
12		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 [MANUAL AIR CONDITIONER].)
13	Start the engine and idle it. Access the ACCS PID using the M-MDS. (See ON-BOARD DIAGNOSTIC TEST [MZR 2.0, MZR 2.5].) Turn the PCM PID ACCS to ON from OFF using the M-MDS simulation function. Measure the voltage between magnetic clutch terminal A (wiring harness-side) and body ground. Is the voltage 10.5 V or more?	Yes	Go to the next step.
13		No	Go to Step 15.
14	Inspect for continuity between magnetic clutch terminal A (wiring harness-side) and body ground. Is there continuity?	Yes	Inspect the magnetic clutch. (See MAGNETIC CLUTCH INSPECTION [MANUAL AIR CONDITIONER].) (See MAGNETIC CLUTCH INSPECTION [FULL-AUTO AIR CONDITIONER].) Replace the magnetic clutch if necessary.
14		No	Inspect the A/C compressor. (poor contact to ground) • If there is any malfunction: ― Repair or replace the malfunctioning part according to the inspection results. • If there is no malfunction: ― Replace the A/C compressor. (internal circuit open)
15	Inspect the A/C relay. (See RELAY INSPECTION.) Is there any malfunction?	Yes	Replace the A/C relay.
15		No	Go to the next step.
16	Switch the ignition to off. Remove the A/C relay. Disconnect the PCM connector. Inspect for continuity between A/C relay and PCM terminal 1I (wiring harness-side). Is there continuity?	Yes	Inspect for open circuit between the following: • Ignition switch (IG2) and A/C relay (vehicles without advanced keyless entry and push button start system) • IG2 relay and A/C relay (vehicles with advanced keyless entry and push button start system) • Battery positive terminal and A/C relay • A/C relay and magnetic clutch Repair or replace the malfunctioning part according to the inspection results.
16		No	Repair or replace the suspected wiring harness.
17	• Verify the test results. ― If normal, return to the diagnostic index to service any additional symptoms. (See SYMPTOM DIAGNOSTIC INDEX [MZR 2.0, MZR 2.5].) ― If a malfunction remains, inspect the related Service Information perform repair or diagnosis. • If the vehicle repaired, troubleshooting is completed. • If the vehicle not repaired or additional diagnostic information not available, replace the PCM. (See PCM REMOVAL/INSTALLATION [MZR 2.0, MZR 2.5].)