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 K (with manual air conditioner)

• Evaporator temperature sensor terminal B—Climate control unit terminal 1L (with full-auto air conditioner)

• Evaporator temperature sensor terminal A—Climate control unit terminal 1J (with full-auto air conditioner)

• 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

Item (definition)

Unit/Condition

Definition

Condition/Specification (Reference)

AC_REQ

Off/On

A/C request signal

• A/C switch off: Off

• A/C switch on: On

ACCS

Off/On

A/C relay

• A/C relay is off: Off

• A/C relay is on: On

STEP

INSPECTION

RESULTS

ACTION

1

• Retrieve the PCM, instrument cluster and climate control unit DTCs using the M-MDS.

  (See ON-BOARD DIAGNOSTIC TEST [SKYACTIV-G 2.5].)

  (See DTC INSPECTION [INSTRUMENT CLUSTER].)

  (See DTC DISPLAY [FULL-AUTO AIR CONDITIONER].)

  (See DTC DISPLAY [MANUAL AIR CONDITIONER].)

• Are any DTCs present?

Yes

Go to the applicable DTC inspection.

(See DTC TABLE [SKYACTIV-G 2.5].)

(See DTC TABLE [INSTRUMENT CLUSTER].)

(See DTC TABLE [FULL-AUTO AIR CONDITIONER].)

(See DTC TABLE [MANUAL AIR CONDITIONER].)

No

Go to the next step.

2

• Access the PCM PID ACCS using the M-MDS.

  (See ON-BOARD DIAGNOSTIC TEST [SKYACTIV-G 2.5].)

• 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

• Access the PCM PID AC_REQ using the M-MDS.

  (See ON-BOARD DIAGNOSTIC TEST [SKYACTIV-G 2.5].)

• 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?

  (See PCM INSPECTION [SKYACTIV-G 2.5].)

Yes

Go to the next step.

No

Go to Step 5.

4

• Inspect the refrigerant pressure sensor.

  (See REFRIGERANT PRESSURE SENSOR INSPECTION [MANUAL AIR CONDITIONER].)

  (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.

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

• 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 1L (wiring harness-side). (with full-auto air conditioner)

• Is the voltage normal?

  (See CLIMATE CONTROL UNIT INSPECTION [MANUAL AIR CONDITIONER].)

  (See CLIMATE CONTROL UNIT INSPECTION [FULL-AUTO AIR CONDITIONER].)

Yes

With manual air conditioner:

• Go to Step 7.

With full-auto air conditioner:

• Go to Step 8.

No

Go to the next step.

6

• Inspect the evaporator temperature sensor.

  (See EVAPORATOR TEMPERATURE SENSOR INSPECTION [MANUAL AIR CONDITIONER].)

  (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 [MANUAL AIR CONDITIONER].)

(See EVAPORATOR TEMPERATURE SENSOR REMOVAL/INSTALLATION [FULL-AUTO AIR CONDITIONER].)

No

Inspect for a 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 K (with manual air conditioner)

• Evaporator temperature sensor terminal B—Climate control unit terminal 1L (with full-auto air conditioner)

• Evaporator temperature sensor terminal A—Climate control unit terminal 1J (with full-auto air conditioner)

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 K (with manual air conditioner)

• Evaporator temperature sensor terminal B—Climate control unit terminal 1L (with full-auto air conditioner)

• Evaporator temperature sensor terminal A—Climate control unit terminal 1J (with full-auto air conditioner)

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

• Verify the information display indication of A/C system while turning on and off the air conditioner using the 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.)

No

A/C switch malfunction, or climate control unit cannot determine the A/C request or transmit the A/C request signal.

• Replace the climate control unit.

  (See CLIMATE CONTROL UNIT REMOVAL/INSTALLATION [MANUAL AIR CONDITIONER].)

  (See CLIMATE CONTROL UNIT REMOVAL/INSTALLATION [FULL-AUTO AIR CONDITIONER].)

8

• Start the engine and idle it.

• Access the PCM PID ACCS using the M-MDS.

  (See ON-BOARD DIAGNOSTIC TEST [SKYACTIV-G 2.5].)

• 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

• 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.

(See MAGNETIC CLUTCH INSPECTION [MANUAL AIR CONDITIONER].)

(See MAGNETIC CLUTCH INSPECTION [FULL-AUTO AIR CONDITIONER].)

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

• Switch the ignition off.

• Remove the A/C relay.

• Inspect the A/C relay.

  (See RELAY INSPECTION.)

• Is there any malfunction?

Yes

Replace the A/C relay.

No

Go to the next step.

11

• 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.

  (See SYMPTOM DIAGNOSTIC INDEX [SKYACTIV-G 2.5].)

• If the malfunction remains, inspect the related Service Bulletins and/or On-line Repair Information and perform 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.