NO.23 A/C DOES NOT WORK SUFFICIENTLY [L5]

NO.23 A/C DOES NOT WORK SUFFICIENTLY [L5]SM2444483

id0103a8802900

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, 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) • 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) • 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

A/C DOES NOT WORK SUFFICIENTLY

DESCRIPTION

• A/C compressor magnetic clutch does not engage when A/C 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)

• 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)

• 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	Retrieve the PCM, BCM, instrument cluster and climate control unit DTCs. (See ON-BOARD DIAGNOSTIC TEST [L5].) (See DTC INSPECTION [BCM].) (See DTC INSPECTION [INSTRUMENT CLUSTER].) (See DTC DISPLAY [FULL-AUTO AIR CONDITIONER].) Are any DTCs present?	Yes	Go to the applicable DTC inspection. (See DTC TABLE [L5].) (See DTC TABLE [BCM].) (See DTC TABLE [INSTRUMENT CLUSTER].) (See DTC TABLE [FULL-AUTO AIR CONDITIONER].)
1		No	Go to the next step.
2	Access the PCM PID ACCS using the M-MDS. (See ON-BOARD DIAGNOSTIC TEST [L5].) 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	Go to the next step.
2		No	Go to Step 12.
3	Start the engine and idle it. Measure the voltage at the climate control unit terminal 1F (wiring harness-side). Is the voltage normal? (See CLIMATE CONTROL UNIT INSPECTION [FULL-AUTO AIR CONDITIONER].)	Yes	Go to Step 6.
3		No	Go to the next step.
4	Turn the ignition switch to the ON position (engine off). Measure the voltage at the climate control unit terminal 1C (wiring harness-side). Is the voltage normal? (See CLIMATE CONTROL UNIT INSPECTION [FULL-AUTO AIR CONDITIONER].)	Yes	Go to the next step.
4		No	Replace the climate control unit. (See CLIMATE CONTROL UNIT REMOVAL/INSTALLATION [FULL-AUTO AIR CONDITIONER].)
5	Inspect for open or short circuit between the following terminals (wiring harness-side): • Climate control unit terminal 1C—evaporator temperature sensor terminal A • Climate control unit terminal 1F—evaporator temperature sensor terminal B Is there any open or short circuit detected?	Yes	Repair or replace the suspected wiring harness.
5		No	Replace the evaporator temperature sensor. (See EVAPORATOR TEMPERATURE SENSOR REMOVAL/INSTALLATION [FULL-AUTO AIR CONDITIONER].)
6	Inspect the refrigerant pressure sensor. (See REFRIGERANT PRESSURE SENSOR INSPECTION [FULL-AUTO AIR CONDITIONER].) Is there any malfunction?	Yes	Go to the next step.
6		No	Go to Step 10.
7	Inspect the refrigerant pressure. (See REFRIGERANT PRESSURE CHECK.) Is there any malfunction?	Yes	Repair or replace the malfunctioning part according to the inspection results.
7		No	Go to the next step.
8	Turn the ignition switch to the ON position (engine off). Measure the voltage at the climate control unit terminal 1N (wiring harness-side). Is the voltage normal? (See CLIMATE CONTROL UNIT INSPECTION [FULL-AUTO AIR CONDITIONER].)	Yes	Go to the next step.
8		No	Replace the climate control unit. (See CLIMATE CONTROL UNIT REMOVAL/INSTALLATION [FULL-AUTO AIR CONDITIONER].)
9	Inspect for open or short circuit between the following terminals (wiring harness-side): • Climate control unit terminal 1J—refrigerant pressure sensor terminal A • Climate control unit terminal 1N—refrigerant pressure sensor terminal B • Climate control unit terminal 1C—refrigerant pressure sensor terminal C Is there any open or short circuit detected?	Yes	Repair or replace the suspected wiring harness.
9		No	Replace the refrigerant pressure sensor. (See REFRIGERANT PRESSURE SENSOR REMOVAL/INSTALLATION [FULL-AUTO AIR CONDITIONER].)
10	Verify the multi information display indication of A/C system while turning on and off the air conditioner by switching the control penal. Does the multi information display indicate properly?	Yes	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.)
10		No	Go to the next step.
11	Inspect the multi information display. (See MULTI INFORMATION DISPLAY INPUT/OUTPUT CHECK MODE.) Is there any malfunction?	Yes	Repair or replace the malfunctioning part according to the inspection results.
11		No	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/INSTALLATION [FULL-AUTO AIR CONDITIONER].)
12	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.
12		No	Go to Step 14.
13	Inspect the A/C compressor magnetic clutch. (See MAGNETIC CLUTCH INSPECTION [FULL-AUTO AIR CONDITIONER].) Is there any malfunction?	Yes	Replace the magnetic clutch. (See MAGNETIC CLUTCH DISASSEMBLY/ASSEMBLY [FULL-AUTO AIR CONDITIONER].)
13		No	Inspect for open or short circuit between battery positive terminal and A/C compressor terminal A. Repair or replace the suspected wiring harness.
14	Inspect the A/C relay. (See RELAY INSPECTION [L5].) Is there any malfunction?	Yes	Replace the A/C relay.
14		No	Go to the next step.
15	Remove the A/C relay. Start the engine and idle it. Measure the voltage at the A/C relay terminal 2 (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 for open circuit between ignition switch terminal B and A/C relay terminal 1. Repair or replace the suspected wiring harness.
15		No	Inspect for open or short to power supply circuit between PCM terminal 1I and A/C relay terminal 2. Repair or replace the suspected wiring harness.
16	Verify test results. • If normal, return to the diagnostic index to service any additional symptoms. (See SYMPTOM DIAGNOSTIC INDEX [L5].) • If the malfunction remains, inspect the related Service Information and perform the repair or diagnosis. ― If the vehicle is repaired, troubleshooting is completed. ― If the vehicle is not repaired or additional diagnostic information is not available, reprogram the PCM if a later calibration is available. Retest.