NO.23 A/C DOES NOT WORK SUFFICIENTLY [SKYACTIV-G 1.5, SKYACTIV-G 2.0, SKYACTIV-G 2.5]


id0103g8802900

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 H (with manual air conditioner)
―  Evaporator temperature sensor terminal A—Climate control unit terminal F (with manual air conditioner)
―  Evaporator temperature sensor terminal B—Climate control unit terminal J (with full-auto air conditioner (single air mix actuator type))
―  Evaporator temperature sensor terminal A—Climate control unit terminal E (with full-auto air conditioner (single air mix actuator type))
―  Evaporator temperature sensor terminal B—Climate control unit terminal 1L (with full-auto air conditioner (dual air mix actuator type))
―  Evaporator temperature sensor terminal A—Climate control unit terminal 1J (with full-auto air conditioner (dual air mix actuator type))
•  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:
―  Front body control module (FBCM) terminal 1C—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


System Wiring Diagram


Vehicles with manual air conditioner

am3zzw00015937


Vehicles with full-auto air conditioner

am3zzw00015938

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.
•  Are any DTCs present?
Yes
Go to the applicable DTC inspection.
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 simulation item ACCS using the M-MDS.
•  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.
No
Go to Step 8.
3
DETERMINE IF MALFUNCTION CAUSE IS REFRIGERANT PRESSURE SENSOR OR OTHER
•  Access the PCM PID AC_REQ using the M-MDS.
•  Monitor the AC_REQ PID while turning on and off the air conditioner using the switch on the control panel.
•  Is the AC_REQ PID value normal?
Yes
Go to the next step.
No
Go to Step 5.
4
INSPECT REFRIGERANT PRESSURE SENSOR
•  Is there any malfunction?
Yes
Repair or replace the malfunctioning part according to the inspection results.
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 H (wiring harness-side). (with manual air conditioner)
•  Measure the voltage at the climate control unit terminal J (wiring harness-side). (with full-auto air conditioner (single air mix actuator type))
•  Measure the voltage at the climate control unit terminal 1L (wiring harness-side). (with full-auto air conditioner (dual air mix actuator type))
Yes
Vehicles with manual air conditioner:
•  Go to Step 7.
Vehicles with full-auto air conditioner:
•  Go to Step 8.
No
Go to the next step.
6
INSPECT EVAPORATOR TEMPERATURE SENSOR
•  Is there any malfunction?
Yes
Replace the evaporator temperature sensor.
No
Inspect for short or open circuit between the following terminals:
•  Evaporator temperature sensor terminal B—Climate control unit terminal H (with manual air conditioner)
•  Evaporator temperature sensor terminal A—Climate control unit terminal F (with manual air conditioner)
•  Evaporator temperature sensor terminal B—Climate control unit terminal J (with full-auto air conditioner (single air mix actuator type))
•  Evaporator temperature sensor terminal A—Climate control unit terminal E (with full-auto air conditioner (single air mix actuator type))
•  Evaporator temperature sensor terminal B—Climate control unit terminal 1L (with full-auto air conditioner (dual air mix actuator type))
•  Evaporator temperature sensor terminal A—Climate control unit terminal 1J (with full-auto air conditioner (dual air mix actuator type))
If there is any malfunction:
―  Refer to the wiring diagram and verify whether or not there is a common connector between the following terminals:
•  Evaporator temperature sensor terminal B—Climate control unit terminal H (with manual air conditioner)
•  Evaporator temperature sensor terminal A—Climate control unit terminal F (with manual air conditioner)
•  Evaporator temperature sensor terminal B—Climate control unit terminal J (with full-auto air conditioner (single air mix actuator type))
•  Evaporator temperature sensor terminal A—Climate control unit terminal E (with full-auto air conditioner (single air mix actuator type))
•  Evaporator temperature sensor terminal B—Climate control unit terminal 1L (with full-auto air conditioner (dual air mix actuator type))
•  Evaporator temperature sensor terminal A—Climate control unit terminal 1J (with full-auto air conditioner (dual air mix actuator type))
If there is a common connector:
•  Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for a short or open circuit.
•  Repair or replace the malfunctioning part.
If there is no common connector:
•  Repair or replace the wiring harness which has a short or open circuit.
7
DETERMINE IF MALFUNCTION CAUSE IS INSTRUMENT CLUSTER OR OTHER
•  Verify the display indication of A/C system while turning on and off the air conditioner using the switch on the control panel.
•  Does the display indicate properly?
Yes
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.
No
Instrument cluster does not receive the A/C request signal from climate control unit or transmit it to PCM.
•  Replace the instrument cluster.
8
DETERMINE IF MALFUNCTION CAUSE IS A/C CONTROL SIGNAL OR MAGNETIC CLUTCH
•  Start the engine and idle it.
•  Access the PCM simulation item ACCS using the M-MDS.
•  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.
No
Go to Step 10.
9
INSPECT IF MALFUNCTION CAUSE IS MAGNETIC CLUTCH OR MAGNETIC CLUTCH GROUND CIRCUIT
•  Switch the ignition 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.
Replace the magnetic clutch if necessary.
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)
10
INSPECT A/C RELAY
•  Switch the ignition off.
•  Remove the A/C relay.
•  Inspect the A/C relay.
•  Is there any malfunction?
Yes
Replace the A/C relay.
No
Go to the next step.
11
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:
•  Front body control module (FBCM) terminal 1C—A/C relay terminal A
•  Battery positive terminal—A/C relay terminal C
•  A/C relay terminal D—Magnetic clutch terminal A
Refer to the wiring diagram and verify whether or not there is a common connector between the following terminals:
•  Front body control module (FBCM) terminal 1C—A/C relay terminal A
•  Battery positive terminal—A/C relay terminal C
•  A/C relay terminal D—Magnetic clutch terminal A
If there is a common connector:
•  Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for an open circuit.
•  Repair or replace the malfunctioning part.
If there is no common connector:
•  Repair or replace the wiring harness which has an open circuit.
No
Refer to the wiring diagram and verify whether or not there is a common connector between A/C relay terminal E and PCM terminal 2AF.
If there is a common connector:
•  Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for an open circuit.
•  Repair or replace the malfunctioning part.
If there is no common connector:
•  Repair or replace the wiring harness which has an open circuit.
12
Verify the test results.
•  If normal, return to the diagnostic index to service any additional symptoms.
•  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.