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Home >> Mazda >> 2016 >> CX-9 Sport, AWD >> Repair and Diagnosis >> Heating, Ventilation & A/C (HVAC) >> HVAC Control Systems >> Symptom Troubleshooting - Climate Control System >> Dual A/C Control Does Not Operate >> Diagnostic Procedure

Diagnostic Procedure

Step Inspection Action
1 VERIFY SYMPTOM 
  • Turn on the A/C.
  • Perform the dual A/C control function for driver and passenger side individually.
  • Is it either the temperature control on driver side or passenger side?
 Yes Go to the next step.
No Go to Step 12.
2 INSPECT TO SEE WHETHER MALFUNCTION IS IN FRONT AIR MIX DOOR OR ELSEWHERE 
  • Turn on the A/C.
  • Change temperature control on the suspected side while in dual mode.
  • Does the front air mix door on the suspect side move smoothly?
 Yes Go to Step 8.
No Go to the next step.
3 INSPECT FRONT AIR MIX ACTUATOR 
 Yes Go to the next step.
No Replace the front air mix actuator on the suspected side, then go to Step 15.
Refer to FRONT AIR MIX ACTUATOR REMOVAL/INSTALLATION .)
4* INSPECT FRONT AIR MIX ACTUATOR CIRCUIT FOR SHORT TO GROUND 
  • Disconnect the front climate control unit connector.

    Refer to FRONT CLIMATE CONTROL UNIT REMOVAL/INSTALLATION .)

  • Inspect for continuity between the following terminals (wiring harness-side) and body ground:

    Driver-side 

    • Front climate control unit terminal 2F
    • Front climate control unit terminal 2H

      Passenger-side 

    • Front climate control unit terminal 2A
    • Front climate control unit terminal 2C
  • Is there continuity?
 Yes Refer to the wiring diagram and verify whether or not there is a common connector between front climate control unit terminal and front air mix actuator terminal.
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 to ground.
  • Repair or replace the malfunctioning part.

    If there is no common connector: 

  • Repair or replace the wiring harness which has a short to ground.

Go to Step 15.
No Go to the next step.
5* INSPECT FRONT AIR MIX ACTUATOR CIRCUIT FOR OPEN CIRCUIT 
  • Front air mix actuator and front climate control unit connectors are disconnected.
  • Inspect for continuity between the following terminals (wiring harness-side):

    Driver-side 

    • Front climate control unit terminal 2F-front air mix actuator terminal D
    • Front climate control unit terminal 2H-front air mix actuator terminal E

      Passenger-side 

    • Front climate control unit terminal 2A-front air mix actuator terminal E
    • Front climate control unit terminal 2C-front air mix actuator terminal D
  • Is there continuity?
 Yes Go to the next step.
No Refer to the wiring diagram and verify whether or not there is a common connector between front climate control unit terminal and front air mix actuator terminal.
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.

Go to Step 15.
6* INSPECT FRONT AIR MIX ACTUATOR CIRCUIT FOR SHORT TO POWER SUPPLY 
  • Front air mix actuator and front climate control unit connectors are disconnected.
  • Connect the negative battery terminal.

    Refer to NEGATIVE BATTERY TERMINAL DISCONNECTION/CONNECTION .)

  • Switch the ignition ON (engine off or on).
  • Measure the voltage at the following terminals (wiring harness-side):

    Driver-side 

    • Front climate control unit terminal 2F
    • Front climate control unit terminal 2H

      Passenger-side 

    • Front climate control unit terminal 2A
    • Front climate control unit terminal 2C
  • Is the voltage 0 V  ?
 Yes Go to the next step.
No Refer to the wiring diagram and verify whether or not there is a common connector between front climate control unit terminal and front air mix actuator terminal.
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 to power supply.
  • Repair or replace the malfunctioning part.

    If there is no common connector: 

  • Repair or replace the wiring harness which has a short to power supply.

Go to Step 15.
7 INSPECT FRONT AIR MIX DOOR 
  • Inspect the suspect side front air mix door.
  • Is the front air mix door normal?
 Yes Replace the front climate control unit, then go to Step 15.
Refer to FRONT CLIMATE CONTROL UNIT REMOVAL/INSTALLATION .)
No Remove the obstruction or replace front A/C unit case on the suspected side, then go to Step 15.
Refer to FRONT A/C UNIT DISASSEMBLY/ASSEMBLY .)
8* INSPECT FRONT AIR MIX ACTUATOR POSITION SENSOR 
  • Inspect the front air mix actuator position sensor on the suspected side.

    Refer to FRONT AIR MIX ACTUATOR INSPECTION .)

  • Is the front air mix actuator position sensor normal?
 Yes Go to the next step.
No Replace the front air mix actuator on the suspected side, then go to Step 15.
Refer to FRONT AIR MIX ACTUATOR REMOVAL/INSTALLATION .)
9* INSPECT FRONT AIR MIX ACTUATOR (POSITION SENSOR) CIRCUIT FOR SHORT TO GROUND 
  • Disconnect the front climate control unit connector.

    Refer to FRONT CLIMATE CONTROL UNIT REMOVAL/INSTALLATION .)

  • Inspect for continuity between the following terminals (wiring harness-side) and body ground:

    Driver-side 

    • Front climate control unit terminal 1X

      Passenger-side 

    • Front climate control unit terminal 1M
  • Is there continuity?
 Yes Refer to the wiring diagram and verify whether or not there is a common connector between front climate control unit terminal and front air mix actuator terminal.
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 to ground.
  • Repair or replace the malfunctioning part.

    If there is no common connector: 

  • Repair or replace the wiring harness which has a short to ground.

Go to Step 15.
No Go to the next step.
10* INSPECT FRONT AIR MIX ACTUATOR (POSITION SENSOR) CIRCUIT FOR OPEN CIRCUIT 
  • Front air mix actuator and front climate control unit connectors are disconnected.
  • Inspect for continuity between the following terminals (wiring harness-side):

    Driver-side 

    • Front climate control unit terminal 1X-front air mix actuator terminal B
    • Front climate control unit terminal 1R-front air mix actuator terminal A
    • Front climate control unit terminal 1I-front air mix actuator terminal C

      Passenger-side 

    • Front climate control unit terminal 1M-front air mix actuator terminal B
    • Front climate control unit terminal 1R-front air mix actuator terminal C
    • Front climate control unit terminal 1I-front air mix actuator terminal A
  • Is there continuity?
 Yes Go to the next step.
No Refer to the wiring diagram and verify whether or not there is a common connector between front climate control unit terminal and front air mix actuator terminal.
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.

Go to Step 15.
11* INSPECT FRONT AIR MIX ACTUATOR (POSITION SENSOR) CIRCUIT FOR SHORT TO POWER SUPPLY 
  • Front air mix actuator and front climate control unit connectors are disconnected.
  • Connect the negative battery terminal.

    Refer to NEGATIVE BATTERY TERMINAL DISCONNECTION/CONNECTION .)

  • Switch the ignition ON (engine off or on).
  • Measure the voltage at the following terminals (wiring harness-side):

    Driver-side 

    • Front climate control unit terminal 1X

      Passenger-side 

    • Front climate control unit terminal 1M
  • Is the voltage 0 V  ?
 Yes Replace the front climate control unit, then go to Step 15.
Refer to FRONT CLIMATE CONTROL UNIT REMOVAL/INSTALLATION .)
No Refer to the wiring diagram and verify whether or not there is a common connector between front climate control unit terminal and front air mix actuator terminal.
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 to power supply.
  • Repair or replace the malfunctioning part.

    If there is no common connector: 

  • Repair or replace the wiring harness which has a short to power supply.

Go to Step 15.
12* INSPECT FRONT AIR MIX ACTUATOR (POSITION SENSOR) CIRCUIT FOR SHORT TO GROUND 
 Yes Refer to the wiring diagram and verify whether or not there is a common connector between front climate control unit terminal and each front actuator/sensor terminal.
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 to ground.
  • Repair or replace the malfunctioning part.

    If there is no common connector: 

  • Repair or replace the wiring harness which has a short to ground.

Go to Step 15.
No Go to the next step.
13* INSPECT FRONT AIR MIX ACTUATOR (POSITION SENSOR) CIRCUIT FOR OPEN CIRCUIT 
  • Front air mix actuator and front climate control unit connectors are disconnected.
  • Inspect for continuity between the following terminals (wiring harness-side):

    Driver-side 

    • Front climate control unit terminal 1R-Front air mix actuator terminal A
    • Front climate control unit terminal 1I-Front air mix actuator terminal C

      Passenger-side 

    • Front climate control unit terminal 1R-Front air mix actuator terminal C
    • Front climate control unit terminal 1I-Front air mix actuator terminal A
  • Is there continuity?
 Yes Go to the next step.
No Refer to the wiring diagram and verify whether or not there is a common connector between front climate control unit terminal and front air mix actuator terminal.
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.

Go to Step 15.
14* INSPECT FRONT AIR MIX ACTUATOR (POSITION SENSOR) CIRCUIT FOR SHORT TO POWER SUPPLY 
  • Front air mix actuator and front climate control unit connectors are disconnected.
  • Connect the negative battery terminal.

    Refer to NEGATIVE BATTERY TERMINAL DISCONNECTION/CONNECTION .)

  • Switch the ignition ON (engine off or on).
  • Measure the voltage at the terminals (wiring harness-side):
    • Front climate control unit terminal 1R
    • Front climate control unit terminal 1I
  • Is the voltage 0 V  ?
 Yes Replace the front climate control unit.
Refer to FRONT CLIMATE CONTROL UNIT REMOVAL/INSTALLATION .)
Go to the next Step.
No Refer to the wiring diagram and verify whether or not there is a common connector between front climate control unit terminal and each front actuator/sensor terminal.
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 to power supply.
  • Repair or replace the malfunctioning part.

    If there is no common connector: 

  • Repair or replace the wiring harness which has a short to power supply.

Go to the next step.
15 VERIFY THAT MALFUNCTION SYMPTOMS DO NOT RECUR AFTER REPAIR 
  • Can the temperatures for the driver-side and passenger-side be adjusted independently?
 Yes Troubleshooting completed. Explain repairs to customer.
No Recheck malfunction symptoms, then repeat from Step 1 if malfunction recurs.
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