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 |
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DESCRIPTION
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• A/C compressor magnetic clutch does not engage when A/C switch is turned on.
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POSSIBLE CAUSE
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• 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:
• 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:
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System Wiring Diagram
Vehicles with manual air conditioner
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Vehicles with full-auto air conditioner
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Diagnostic Procedure
STEP |
INSPECTION |
RESULTS |
ACTION |
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1
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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?
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Yes
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Go to the applicable DTC inspection.
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No
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Go to the next step.
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2
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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?
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Yes
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Go to the next step.
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No
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Go to Step 8.
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3
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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?
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Yes
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Go to the next step.
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No
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Go to Step 5.
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4
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INSPECT REFRIGERANT PRESSURE SENSOR
• Inspect the refrigerant pressure sensor.
• Is there any malfunction?
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Yes
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Repair or replace the malfunctioning part according to the inspection results.
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No
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Inspect the following:
• Refrigerant charging amount
• A/C compressor seized
Repair or replace the malfunctioning part according to the inspection results if necessary.
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5
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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))
• Is the voltage normal?
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Yes
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Vehicles with manual air conditioner:
• Go to Step 7.
Vehicles with full-auto air conditioner:
• Go to Step 8.
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No
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Go to the next step.
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6
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INSPECT EVAPORATOR TEMPERATURE SENSOR
• Inspect the evaporator temperature sensor.
• Is there any malfunction?
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Yes
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Replace the evaporator temperature sensor.
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No
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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:
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7
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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?
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Yes
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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.
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No
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Instrument cluster does not receive the A/C request signal from climate control unit or transmit it to PCM.
• Replace the instrument cluster.
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8
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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?
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Yes
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Go to the next step.
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No
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Go to Step 10.
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9
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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?
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Yes
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Inspect the magnetic clutch.
Replace the magnetic clutch if necessary.
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No
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Inspect the A/C compressor. (poor contact to ground)
• If there is any malfunction:
• If there is no malfunction:
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10
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INSPECT A/C RELAY
• Switch the ignition off.
• Remove the A/C relay.
• Inspect the A/C relay.
(See RELAY INSPECTION.)
• Is there any malfunction?
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Yes
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Replace the A/C relay.
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No
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Go to the next step.
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11
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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?
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Yes
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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.
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No
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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.
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12
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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.
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