NO.23 A/C DOES NOT WORK SUFFICIENTLY [MZR 1.6]

id0103f9802900

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

•  Improper magnetic clutch clearance

•  Refrigerant pressure sensor is stuck open

•  Improper refrigerant charge amount

•  Evaporator temperature sensor malfunction

•  Instrument cluster malfunction (does not transmit A/C request signal to PCM)

•  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 (with full-auto air conditioner)

•  Communication error between PCM and instrument cluster

•  Open or short to power supply circuit between instrument cluster terminal L and climate control unit terminal B (with manual air conditioner)

•  Poor ground of A/C magnetic clutch

•  Open A/C magnetic clutch

•  A/C relay stuck open

•  Improper A/C cut-off control

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

•  Open circuit in wiring harness between A/C relay and front body control module (FBCM)

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

•  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	• Improper magnetic clutch clearance • Refrigerant pressure sensor is stuck open • Improper refrigerant charge amount • Evaporator temperature sensor malfunction • Instrument cluster malfunction (does not transmit A/C request signal to PCM) • 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 (with full-auto air conditioner) • Communication error between PCM and instrument cluster • Open or short to power supply circuit between instrument cluster terminal L and climate control unit terminal B (with manual air conditioner) • Poor ground of A/C magnetic clutch • Open A/C magnetic clutch • A/C relay stuck open • Improper A/C cut-off control • Open circuit in wiring harness between A/C relay and PCM • Open circuit in wiring harness between A/C relay and front body control module (FBCM) • Open circuit in wiring harness between A/C relay and battery • Open circuit in wiring harness between A/C relay and magnetic clutch • PCM malfunction

Diagnostic Procedure

STEP	INSPECTION	ACTION
1	Retrieve the PCM, instrument cluster, and climate control unit (with full-auto air conditioner) DTCs. (See ON-BOARD DIAGNOSTIC TEST [MZR 1.6].) (See DTC INSPECTION [INSTRUMENT CLUSTER].) (See DTC DISPLAY [FULL-AUTO AIR CONDITIONER].) Are any DTCs present?	Yes	Go to the appropriate DTC inspection. (See DTC TABLE [MZR 1.6].) (See DTC TABLE [INSTRUMENT CLUSTER].) (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 1.6].) Start the engine and idle it. Turn the PID ACCS to On from Off using the M-MDS simulation function. Is the magnetic clutch engaged?	Yes	Go to the next step.
2		No	Go to Step 11.
3	Access the AC_REQ PID using the M-MDS. (See ON-BOARD DIAGNOSTIC TEST [MZR 1.6].) Monitor the AC_REQ PID while turning on and off the air conditioner by switching the control panel. Is the PID value normal? (See PCM INSPECTION [MZR 1.6].)	Yes	Go to the next step.
3		No	Full-auto air conditioner: • Go to Step 6. Manual air conditioner: • Go to Step 7.
4	Inspect the refrigerant pressure sensor. (See REFRIGERANT PRESSURE SENSOR INSPECTION [FULL-AUTO AIR CONDITIONER].) (See REFRIGERANT PRESSURE SENSOR INSPECTION [MANUAL AIR CONDITIONER].) Is the refrigerant pressure sensor normal?	Yes	Go to the next step.
4		No	Replace the refrigerant pressure sensor. (See REFRIGERANT PRESSURE SENSOR REMOVAL/INSTALLATION [FULL-AUTO AIR CONDITIONER].) (See REFRIGERANT PRESSURE SENSOR REMOVAL/INSTALLATION [MANUAL AIR CONDITIONER].)
5	Inspect for following: • Refrigerant charging amount • A/C compressor seizure Is there any malfunction?	Yes	Repair or replace the malfunctioning part according to the inspection results.
5		No	Manual air conditioner: • Go to Step 9.
6	Connect the M-MDS to the DLC-2. Access the climate control unit PID EVA_TMP_SEN. (See PID/DATA MONITOR DISPLAY [FULL-AUTO AIR CONDITIONER].) Monitor the EVA_TMP_SEN PID while turning on and off the air conditioner by switching the control panel. Is the PID value normal? (See CLIMATE CONTROL UNIT INSPECTION [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 with it removed. Measure the voltage at the climate control unit terminal H (wiring harness-side). Is the voltage within the specified? (See CLIMATE CONTROL UNIT INSPECTION [MANUAL AIR CONDITIONER].)	Yes	Go to Step 9.
7		No	Go to the next step.
8	Inspect the evaporator temperature sensor. (See EVAPORATOR TEMPERATURE SENSOR INSPECTION [FULL-AUTO AIR CONDITIONER].) (See EVAPORATOR TEMPERATURE SENSOR INSPECTION [MANUAL AIR CONDITIONER].) Is there any malfunction?	Yes	Replace the evaporator temperature sensor. (See EVAPORATOR TEMPERATURE SENSOR REMOVAL/INSTALLATION [FULL-AUTO AIR CONDITIONER].) (See EVAPORATOR TEMPERATURE SENSOR REMOVAL/INSTALLATION [MANUAL AIR CONDITIONER].)
8		No	Inspect and repair for open or short circuit between evaporator temperature sensor and climate control unit.
9	Remove the climate control unit. (See CLIMATE CONTROL UNIT REMOVAL/INSTALLATION [MANUAL AIR CONDITIONER].) Reconnect the climate control unit connector with it removed. Measure the voltage at the climate control unit terminal B (wiring harness-side) while turning on and off air conditioner by switching the control panel. Is the voltage change in specified according to the control panel switching? (See CLIMATE CONTROL UNIT INSPECTION [MANUAL AIR CONDITIONER].)	Yes	Replace the instrument cluster. (Instrument cluster does not receive the A/C request signal from climate control unit or transmit to PCM.) (See INSTRUMENT CLUSTER REMOVAL/INSTALLATION.)
9		No	Go to the next step.
10	Inspect for open or short to power supply in wiring harness between instrument cluster terminal L (wiring harness-side) and climate control unit terminal B (wiring harness-side). Is there any malfunction?	Yes	Repair or replace the suspected wiring harness.
10		No	Replace the climate control unit. (A/C switch malfunction or climate control unit does not determine A/C request or transmit to the A/C request signal.) (See CLIMATE CONTROL UNIT REMOVAL/INSTALLATION [MANUAL AIR CONDITIONER].)
11	Disconnect the magnetic clutch connector. Start the engine and idle it. Turn the PID ACCS to On from Off using the M-MDS simulation function. Measure the voltage at the magnetic clutch terminal A (wiring harness-side). Is the voltage 10.5 V or more?	Yes	Go to the next step.
11		No	Go to Step 13.
12	Inspect the A/C compressor magnetic clutch. (See MAGNETIC CLUTCH INSPECTION [MZR 1.6].) Is the magnetic clutch normal?	Yes	Inspect and repair for open or short circuit between battery positive terminal and magnetic clutch terminal A.
12		No	Replace the magnetic clutch.
13	Inspect the A/C relay. (See RELAY INSPECTION.) Is the A/C relay normal?	Yes	Go to the next step.
13		No	Replace the A/C relay.
14	Switch the ignition off. Remove the A/C relay. Disconnect the PCM connector. Inspect for continuity between A/C relay terminal E (wiring harness-side) and PCM terminal 1AT (wiring harness-side). Is there continuity?	Yes	Inspect the following: • Between front body control module (FBCM) and A/C relay • Between battery positive terminal and A/C relay • Between A/C relay and magnetic clutch ― If there is any malfunction: • Repair or replace the malfunctioning part according to the inspection results.
14		No	Repair or replace the suspected wiring harness.
15	Verify the test results. • If normal, return to diagnostic index to service any additional symptoms. (See SYMPTOM DIAGNOSTIC INDEX [MZR 1.6].) • If malfunction remains, inspect related Service information perform repair or diagnosis. ― If vehicle repaired, troubleshooting completed. ― If vehicle not repaired or additional diagnostic information not available, replace the PCM. (See PCM REMOVAL/INSTALLATION [MZR 1.6].)