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Home >> Mazda >> 2016 >> 6 Sport, Automatic Trans >> Repair and Diagnosis >> Engine Performance >> System >> Symptom Troubleshooting - Engine Control System >> No. 23 A/C Does Not Work Sufficiently >> Diagnostic Procedure
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Diagnostic Procedure

STEP INSPECTION RESULTS ACTION
1 VERIFY PCM, INSTRUMENT CLUSTER AND CLIMATE CONTROL UNIT DTC 
 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 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.

    (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 DETERMINE IF MALFUNCTION CAUSE IS REFRIGERANT PRESSURE SENSOR OR OTHER 
 Yes Go to the next step.
No Go to Step 5.
4 INSPECT REFRIGERANT PRESSURE SENSOR 
 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 J (wiring harness-side). (with manual air conditioner system)
  • Measure the voltage at the climate control unit terminal 1L (wiring harness-side). (with full-auto air conditioner system)
  • 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 system:
  • Go to Step 7.

With full-auto air conditioner system:

  • Go to Step 8.
No Go to the next step.
6 INSPECT EVAPORATOR TEMPERATURE SENSOR 
 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 J (with manual air conditioner system)
  • Evaporator temperature sensor terminal A-Climate control unit terminal E (with manual air conditioner system)
  • Evaporator temperature sensor terminal B-Climate control unit terminal 1L (with full-auto air conditioner system)
  • Evaporator temperature sensor terminal A-Climate control unit terminal 1J (with full-auto air conditioner system)

    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 J (with manual air conditioner system)
      • Evaporator temperature sensor terminal A-Climate control unit terminal E (with manual air conditioner system)
      • Evaporator temperature sensor terminal B-Climate control unit terminal 1L (with full-auto air conditioner system)
      • Evaporator temperature sensor terminal A-Climate control unit terminal 1J (with full-auto air conditioner system)

        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.
No Instrument cluster does not receive the A/C request signal from climate control unit or transmit it to PCM.
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.

    (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 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.
(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 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?
 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.

    (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.
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