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Home >> Mazda >> 2013 >> CX-5 Sport, FWD, Automatic Trans >> Repair and Diagnosis >> Engine Performance >> System >> Symptom Troubleshooting [Engine Control System] >> No.23 A/C Does Not Work Sufficiently >> Diagnostic Procedure

Diagnostic Procedure

DIAGNOSTIC PROCEDURE DESCRIPTION

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 2.0] ).
(See DTC TABLE [INSTRUMENT CLUSTER] ).
(See DTC TABLE [FULL-AUTO 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 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.
No Go to Step 9.
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?
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 H (wiring harness-side). (vehicles with manual air conditioner)
  • Measure the voltage at the climate control unit terminal 1F (wiring harness-side). (vehicles 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 Vehicles with manual air conditioner:
  • Go to Step 7.

Vehicles with full-auto air conditioner:
  • Go to Step 9.
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 short or open circuit between the following terminals:
  • Evaporator temperature sensor terminal B-Climate control unit terminal H (vehicles with manual air conditioner)
  • Evaporator temperature sensor terminal A-Climate control unit terminal F (vehicles with manual air conditioner)
  • Evaporator temperature sensor terminal B-Climate control unit terminal 1F (vehicles with full-auto air conditioner)
  • Evaporator temperature sensor terminal A-Climate control unit terminal 1X (vehicles with full-auto air conditioner)

Repair or replace the suspected wiring harness if necessary.
7 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.
No Go to the next step.
8 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 B (wiring harness-side) and instrument cluster terminal L (wiring harness-side).
  • Is there any malfunction?
Yes Repair or replace the suspected wiring harness.
No A/C switch malfunction, or climate control unit can not determine the A/C request or transmit the A/C request signal.
9 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.
No Go to Step 11.
10 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 [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)
11 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.
No Go to the next step.
12 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 Repair or replace the wiring harness for a possible open circuit.
No Repair or replace the wiring harness for a possible open circuit.
13 Verify the test results.
  • If normal, return to the diagnostic index to service any additional symptoms.

    (See SYMPTOM DIAGNOSTIC INDEX ).

  • 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.