NO.23 A/C DOES NOT WORK SUFFICIENTLY [SKYACTIV-G 2.0]

id0103e6802900

23

A/C DOES NOT WORK SUFFICIENTLY

DESCRIPTION

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

POSSIBLE CAUSE

•  PCM, instrument cluster or climate control unit 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 the following terminals:

―  Evaporator temperature sensor terminal B—Climate control unit terminal 1C

―  Evaporator temperature sensor terminal A—Climate control unit terminal 1G

•  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 A/C request signal)

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

•  A/C relay stuck open

•  Open circuit in wiring harness between the following terminals:

―  Ignition switch (IG2)^*1/Relay block (IG2 relay)^*2—A/C relay terminal A

―  Battery positive terminal—A/C relay terminal C

―  A/C relay terminal D—Magnetic clutch terminal A

―  A/C relay terminal E—PCM terminal 2AF

23	A/C DOES NOT WORK SUFFICIENTLY
DESCRIPTION	• A/C compressor magnetic clutch does not engage when A/C switch is turned on.
POSSIBLE CAUSE	• PCM, instrument cluster or climate control unit 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 the following terminals: ― Evaporator temperature sensor terminal B—Climate control unit terminal 1C ― Evaporator temperature sensor terminal A—Climate control unit terminal 1G • 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 A/C request signal) • Open circuit in wiring harness between magnetic clutch and body ground • A/C relay stuck open • Open circuit in wiring harness between the following terminals: ― Ignition switch (IG2)^1/Relay block (IG2 relay)^2—A/C relay terminal A ― Battery positive terminal—A/C relay terminal C ― A/C relay terminal D—Magnetic clutch terminal A ― A/C relay terminal E—PCM terminal 2AF

*1 :Vehicles without advanced keyless entry and push button start system

*2 :Vehicles with advanced keyless entry and push button start system

Diagnostic Procedure

STEP	INSPECTION	RESULTS	ACTION
1	VERIFY PCM, INSTRUMENT CLUSTER AND CLIMATE CONTROL UNIT DTC • Retrieve the PCM, instrument cluster and climate control unit DTCs using the M-MDS. (See ON-BOARD DIAGNOSTIC TEST [SKYACTIV-G 2.0].) (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 [SKYACTIV-G 2.0].) (See DTC TABLE [INSTRUMENT CLUSTER].) (See DTC TABLE [FULL-AUTO AIR CONDITIONER].)
1		No	Go to the next step.
2	DETERMINE IF MALFUNCTION CAUSE IS A/C RELAY CONTROL SIGNAL OR A/C REQUEST SIGNAL • Access the PCM PID ACCS using the M-MDS. (See ON-BOARD DIAGNOSTIC TEST [SKYACTIV-G 2.0].) • 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	Go to the next step.
2		No	Go to Step 10.
3	DETERMINE IF MALFUNCTION CAUSE IS REFRIGERANT PRESSURE SENSOR OR OTHER • Access the PCM PID AC_REQ using the M-MDS. (See ON-BOARD DIAGNOSTIC TEST [SKYACTIV-G 2.0].) • Monitor the AC_REQ PID while turning on and off the air conditioner with switch on the control panel. • Is the AC_REQ PID value normal? (See PCM INSPECTION [SKYACTIV-G 2.0].)	Yes	Go to the next step.
3		No	Go to Step 5.
4	INSPECT REFRIGERANT PRESSURE SENSOR • Inspect the refrigerant pressure sensor. (See REFRIGERANT PRESSURE SENSOR INSPECTION [FULL-AUTO AIR CONDITIONER].) • Is there any malfunction?	Yes	Repair or replace the malfunctioning part according to the inspection results.
4		No	Inspect the following: • Refrigerant charging amount • A/C compressor seized Repair or replace the malfunctioning part according to the inspection results if necessary.
5	DETERMINE IF MALFUNCTION CAUSE IS EVAPORATOR TEMPERATURE SENSOR OR OTHER • 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	Vehicles with multi information display: • Go to Step 7. Vehicles without multi information display: • Go to Step 8.
5		No	Go to the next step.
6	INSPECT EVAPORATOR TEMPERATURE SENSOR • Inspect the evaporator temperature sensor. (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 [FULL-AUTO AIR CONDITIONER].)
6		No	Inspect for short or open circuit between the following terminals: • Evaporator temperature sensor terminal B—Climate control unit terminal 1C • Evaporator temperature sensor terminal A—Climate control unit terminal 1G Repair or replace the suspected wiring harness if necessary.
7	DETERMINE IF MALFUNCTION CAUSE IS INSTRUMENT CLUSTER OR OTHER • Verify the multi information display indication of A/C system while turning on and off the air conditioner with switch on the control panel. • Does the multi information display indicate properly?	Yes	Instrument cluster does not receive the A/C request signal from climate control unit or transmit it to PCM. • Replace the instrument cluster. (See INSTRUMENT CLUSTER REMOVAL/INSTALLATION.)
7		No	Go to Step 9.
8	DETERMINE IF MALFUNCTION CAUSE IS INSTRUMENT CLUSTER OR OTHER • Verify the information display indication of A/C system while turning on and off the air conditioner with switch on the control panel. • Does the information display indicate properly?	Yes	Instrument cluster does not receive the A/C request signal from climate control unit or transmit it to PCM. • Replace the instrument cluster. (See INSTRUMENT CLUSTER REMOVAL/INSTALLATION.)
8		No	Go to the next step.
9	DETERMINE IF MALFUNCTION CAUSE IS A/C REQUEST SIGNAL RELATED WIRING HARNESS OR CLIMATE CONTROL UNIT • Switch the ignition to off. • 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.
9		No	A/C switch malfunction, or climate control unit can not determine the A/C request or transmit the A/C request signal. • Replace the climate control unit. (See CLIMATE CONTROL UNIT REMOVAL/INSTALLATION [FULL-AUTO AIR CONDITIONER].)
10	DETERMINE IF MALFUNCTION CAUSE IS A/C CONTROL SIGNAL OR MAGNETIC CLUTCH • Start the engine and idle it. • Access the PCM PID ACCS using the M-MDS. (See ON-BOARD DIAGNOSTIC TEST [SKYACTIV-G 2.0].) • Turn the ACCS PID 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.
10		No	Go to Step 12.
11	INSPECT IF MALFUNCTION CAUSE IS MAGNETIC CLUTCH OR MAGNETIC CLUTCH GROUND CIRCUIT • Switch the ignition to off. • Disconnect the magnetic clutch connector. • Inspect for continuity between magnetic clutch terminal A (part-side) and body ground. • Is there continuity?	Yes	Inspect the magnetic clutch. (See MAGNETIC CLUTCH INSPECTION [FULL-AUTO AIR CONDITIONER].) Replace the magnetic clutch if necessary.
11		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)
12	INSPECT A/C RELAY • Switch the ignition to off. • Remove the A/C relay. • Inspect the A/C relay. (See RELAY INSPECTION.) • Is there any malfunction?	Yes	Replace the A/C relay.
12		No	Go to the next step.
13	INSPECT A/C RELAY CONTROL CIRCUIT FOR OPEN CIRCUIT • A/C relay is removed. • Disconnect the PCM connector. • Inspect for continuity between A/C relay terminal E (wiring harness-side) and PCM terminal 2AF (wiring harness-side). • Is there continuity?	Yes	Inspect for continuity between the following: • Ignition switch (IG2)^1/Relay block (IG2 relay)^2—A/C relay terminal A • Battery positive terminal—A/C relay terminal C • A/C relay terminal D—Magnetic clutch terminal A Repair or replace the wiring harness for a possible open circuit.
13		No	Repair or replace the wiring harness for a possible open circuit.
14	Verify the test results. • If normal, return to the diagnostic index to service any additional symptoms. (See SYMPTOM DIAGNOSTIC INDEX [SKYACTIV-G 2.0].) • If a 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, replace the PCM. (See PCM REMOVAL/INSTALLATION [SKYACTIV-G 2.0].)