NO.23 A/C DOES NOT WORK SUFFICIENTLY [MZI-3.7]

id0103d2802900

23

A/C DOES NOT WORK SUFFICIENTLY

DESCRIPTION

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

POSSIBLE CAUSE

•  PCM or climate control unit DTC is stored.

•  Refrigerant pressure switch malfunction (PCM connector (2 types))

•  Refrigerant pressure sensor malfunction (PCM connector (3 types))

•  Improper refrigerant charging amount

•  Seized A/C compressor

•  Front evaporator temperature sensor malfunction

•  Open or short circuit in wiring harness between front evaporator temperature sensor and front climate control unit

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

•  Open or short circuit in wiring harness between front climate control unit terminal 2A and instrument cluster terminal 1C

•  A/C compressor malfunction

•  Open circuit in wiring harness between magnetic clutch terminal A and body ground

•  A/C relay malfunction

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

•  Open circuit in wiring harness between main relay No.1 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 magnetic clutch

23	A/C DOES NOT WORK SUFFICIENTLY
DESCRIPTION	• A/C compressor magnetic clutch does not engage when A/C is turned on.
POSSIBLE CAUSE	• PCM or climate control unit DTC is stored. • Refrigerant pressure switch malfunction (PCM connector (2 types)) • Refrigerant pressure sensor malfunction (PCM connector (3 types)) • Improper refrigerant charging amount • Seized A/C compressor • Front evaporator temperature sensor malfunction • Open or short circuit in wiring harness between front evaporator temperature sensor and front climate control unit • Instrument cluster malfunction (Does not receive A/C request signal from climate control unit or transmit it 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.) • Open or short circuit in wiring harness between front climate control unit terminal 2A and instrument cluster terminal 1C • A/C compressor malfunction • Open circuit in wiring harness between magnetic clutch terminal A and body ground • A/C relay malfunction • Open circuit in wiring harness between A/C relay and PCM • Open circuit in wiring harness between main relay No.1 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 magnetic clutch

Diagnostic procedure

STEP	INSPECTION	RESULTS	ACTION
1	Retrieve the PCM and climate control unit DTCs using the M-MDS. (See ON-BOARD DIAGNOSTIC TEST [MZI-3.7 (PCM CONNECTOR (2 TYPES))].) (See ON-BOARD DIAGNOSTIC TEST [MZI-3.7 (PCM CONNECTOR (3 TYPES))].) (See DIAGNOSTIC TROUBLE CODE NUMBER INSPECTION.) Are there any DTCs displayed?	Yes	Go to the appropriate DTC inspection. (See DTC TABLE [MZI-3.7 (PCM CONNECTOR (2 TYPES))].) (See DTC TABLE [MZI-3.7 (PCM CONNECTOR (3 TYPES))].) (See DIAGNOSTIC TROUBLE CODE NUMBER INSPECTION.)
1		No	Go to the next step.
2	Access the PCM PID ACCS using the M-MDS. (See ON-BOARD DIAGNOSTIC TEST [MZI-3.7 (PCM CONNECTOR (2 TYPES))].) (See ON-BOARD DIAGNOSTIC TEST [MZI-3.7 (PCM CONNECTOR (3 TYPES))].) Start the engine and idle it. Turn the PCM 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 9.
3	Measure the voltage at the following terminal (wiring harness-side): • PCM connector (2 types): ― PCM terminal 1R • PCM connector (3 types): ― PCM terminal 1M Is the voltage normal? (See PCM INSPECTION [MZI-3.7].)	Yes	Go to Step 5.
3		No	Go to the next step.
4	Inspect the following: • PCM connector (2 types): ― Refrigerant pressure switch (See REFRIGERANT PRESSURE SWITCH INSPECTION.) • PCM connector (3 types): ― Refrigerant pressure sensor (See REFRIGERANT PRESSURE SENSOR INSPECTION.) Is there any malfunction?	Yes	Replace the following: • PCM connector (2 types): ― Refrigerant pressure switch (See REFRIGERANT PRESSURE SWITCH REMOVAL/INSTALLATION.) • PCM connector (3 types): ― Refrigerant pressure sensor (See REFRIGERANT PRESSURE SENSOR REMOVAL/INSTALLATION.)
4		No	Inspect the following: • Refrigerant charging amount • A/C compressor for seizure Repair or replace the malfunctioning part according to the inspection results.
5	Remove the front climate control unit. (See FRONT CLIMATE CONTROL UNIT REMOVAL/INSTALLATION.) Reconnect the front climate control unit connector. Measure the voltage at the front climate control unit terminal 2H (wiring harness-side). Is the voltage normal? (See FRONT CLIMATE CONTROL UNIT INSPECTION.)	Yes	Go to Step 7.
5		No	Go to the next step.
6	Inspect the front evaporator temperature sensor. (See FRONT EVAPORATOR TEMPERATURE SENSOR INSPECTION.) Is there any malfunction?	Yes	Replace the front evaporator temperature sensor. (See FRONT EVAPORATOR TEMPERATURE SENSOR REMOVAL/INSTALLATION.)
6		No	Inspect for open or short circuit between front evaporator temperature sensor and front climate control unit. Repair or replace suspected wiring harness and connector.
7	Remove the front climate control unit. (See FRONT CLIMATE CONTROL UNIT REMOVAL/INSTALLATION.) Reconnect the front climate control unit connector. Start the engine and idle it. Measure the voltage at the front climate control unit terminal 2A (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? • Specification ― Turn on the A/C: Below 1.0 V ― Turn off the A/C: Approx. 5 V	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.)
7		No	Go to the next step.
8	Inspect for open or short circuit between front climate control unit terminal 2A (wiring harness-side) and instrument cluster terminal 1C (wiring harness-side). Is there any malfunction?	Yes	Repair or replace suspected wiring harness and connector.
8		No	Replace the front 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 FRONT CLIMATE CONTROL UNIT REMOVAL/INSTALLATION.)
9	Start the engine and idle it. Turn the PCM PID ACCS to ON from OFF using the M-MDS simulation function. (See ON-BOARD DIAGNOSTIC TEST [MZI-3.7 (PCM CONNECTOR (2 TYPES))].) (See ON-BOARD DIAGNOSTIC TEST [MZI-3.7 (PCM CONNECTOR (3 TYPES))].) Measure the voltage at the magnetic clutch terminal A (wiring harness-side). Is the voltage specified? • Specification ― 10.5 V or more	Yes	Go to the next step.
9		No	Go to Step 11.
10	Inspect for continuity between magnetic clutch terminal A (wiring harness-side) and body ground. Is there continuity?	Yes	Replace the A/C compressor. (See A/C COMPRESSOR REMOVAL/INSTALLATION.)
10		No	Repair or replace suspected wiring harness and connector.
11	Inspect the A/C relay. (See RELAY INSPECTION.) Is there any malfunction?	Yes	Replace the A/C relay.
11		No	Go to the next step.
12	Switch the ignition to off. Disconnect the A/C relay and PCM connectors. Inspect for continuity between the following (wiring harness-side): • PCM connector (2 types): ― A/C relay and PCM terminal 1N • PCM connector (3 types): ― A/C relay and PCM terminal 1W Is there continuity?	Yes	Inspect for open circuit between the following: • Main relay No.1 and A/C relay • Battery positive terminal and A/C relay • A/C relay and magnetic clutch Repair or replace suspected wiring harness and connector.
12		No	Repair or replace suspected wiring harness and connector.
13	• Verify test results. ― If normal, return to diagnostic index to service any additional symptoms. (See SYMPTOM DIAGNOSTIC INDEX [MZI-3.7].) ― If malfunction remains, inspect related Service 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 [MZI-3.7].)