Contents Wiring diagrams Section: Automatic HVAC System All sections

Control System (HVAC): Diagnosis Mazda CX-9 I

Automatic HVAC System 4 illustrations ~231 words

FRONT CLIMATE CONTROL UNIT INSPECTION

  1. Connect the front climate control unit connector.
  2. Turn the ignition switch to the ON position.
  3. Connect the negative (-) lead of the tester to body ground.
  4. By inserting the positive (+) lead of the tester into each front climate control unit terminal, measure the voltage according to the terminal voltage table. If there is any malfunction, inspect the parts under "Inspection item (s)". If the parts under "Inspection item (s)" are found to be normal, replace the front climate control unit.

Scheme 49

Scheme 49: Terminal Voltage Table (Reference)
TerminalSignal nameConnected toMeasurement conditionVoltage (V)Inspection item (s)
1AMotor operationDriver-side front air mix actuatorTemperature control dial (driver side): Moving towards COLD1.0 or lessWiring harness: continuity, short circuit (Front climate control unit-driver-side front air mix actuator: 1A-G, 1F-F) Driver-side front air mix actuator
Temperature control dial (driver side): Moving towards HOTB+
1BB+BCMUnder any conditionB+Wiring harness: continuity, short circuit (Front climate control unit-BCM: 1B-5H) BCM
1CMotor operationPassenger-side front air mix actuatorTemperature control dial (passenger side): Moving towards COLDB+Wiring harness: continuity, short circuit (Front climate control unit-passenger-side front air mix actuator: 1C-G, 1E-F) Passenger-side front air mix actuator
Temperature control dial (passenger side): Moving towards HOT1.0 or less
1DSeat warmer (LH) on/offSeat warmer relaySeat warmer switch offB+Wiring harness: continuity, short circuit (Front climate control unit-seat warmer (LH) relay (relay block): 1D-A) Seat warmer (LH) relay
Seat warmer switch on1.0 or less
1EMotor operationPassenger-side front air mix actuatorTemperature control dial (passenger side): Moving towards COLD1.0 or lessWiring harness: continuity, short circuit (Front climate control unit-passenger-side front air mix actuator: 1C-G, 1E-F) Passenger-side front air mix actuator
Temperature control dial (passenger side): Moving towards HOTB+
1FMotor operationDriver-side front air mix actuatorTemperature control dial (driver side): Moving towards COLDB+Wiring harness: continuity, short circuit (Front climate control unit-driver-side front air mix actuator: 1A-G, 1F-F) Driver-side front air mix actuator
Temperature control dial (driver-side): Moving towards HOT1.0 or less
1GMotor operationRear air mix actuatorTemperature control dial (rear side): Moving towards COLDB+Wiring harness: continuity, short circuit (Front climate control unit-Rear air mix actuator: 1G-F, 1I-G) Rear air mix actuator
Temperature control dial (rear side): Moving towards HOT1.0 or less
1HMotor operationFront airflow mode actuatorDefroster switch on1.0 or lessWiring harness: continuity, short circuit (Front climate control unit-front airflow mode actuator: 1H-G, 1J-F) Front airflow mode actuator
Mode switch: Moving towards VENTB+
1IMotor operationRear air mix actuatorTemperature control dial (rear side): Moving towards COLD1.0 or lessWiring harness: continuity, short circuit (Front climate control unit-Rear air mix actuator: 1G-F, 1I-G) Rear air mix actuator
Temperature control dial (rear side): Moving towards HOTB+
1JMotor operationFront airflow mode actuatorDefroster switch onB+Wiring harness: continuity, short circuit (Front climate control unit-front airflow mode actuator: 1H-G, U-F) Front airflow mode actuator
Mode switch: Moving towards VENT1.0 or less
1KSeat warmer (RH) on/offSeat warmer relaySeat warmer switch offB+Wiring harness: continuity, short circuit (Front climate control unit-seat warmer (RH) relay (main fuse block): 1K-A) Seat warmer (RH) relay
Seat warmer switch on1.0 or less
1LMotor operationRear airflow mode actuatorTemperature control dial (rear side): Moving towards HOTB+Wiring harness: continuity, short circuit (Front climate control unit-Rear airflow mode actuator: 1L-G, 1N-F) Rear airflow mode actuator
Temperature control dial (rear side): Moving towards COLD1.0 or less
1MMotor operationAir intake actuatorREC switch: Switched to RECIRCULATEB+Wiring harness: continuity, short circuit (Front climate control unit-air intake actuator: 1M-A, 10-C) Air intake actuator
REC switch: Switched to FRESH1.0 or less
1NMotor operationRear airflow mode actuatorTemperature control dial (rear side): Moving towards HOT1.0 or lessWiring harness: continuity, short circuit (Front climate control unit-Rear airflow mode actuator: 1L-G, 1N-F) Rear airflow mode actuator
Temperature control dial (rear side): Moving towards COLDB+
1OMotor operationAir intake actuatorREC switch: Switched to RECIRCULATE1.0 or lessWiring harness: continuity, short circuit (Front climate control unit-air intake actuator: 1M-A, 1O-C) Air intake actuator
REC switch: Switched to FRESHB+
1PFront blower motor feedbackFront power MOS FETAirflow volume control dialOffApprox. 7.3Wiring harness: continuity, short circuit (Front climate control unit-front power MOS FET: 1P C, 1R A) Wiring harness: continuity (Front power MOS FET-body ground: D-ground) Front power MOS FET Front blower motor Front blower relay HEATER 50 A fuse
1st.Approx. 5.4
2nd.Approx. 4.6
3rd.Approx. 3.7
4th.Approx. 2.9
5th.Approx. 2.0
6th.Approx. 1.1
7th1.0 or less
1QRear window defroster switchRear window defroster relayRear window defroster switch on1.0 or lessWiring harness: continuity, short circuit (Front climate control unit-rear window defroster relay (main fuse block): 1Q-A) Rear window defroster relay
Rear window defroster switch offB+Front climate control unit: terminal voltage (1W, 1X)
1RFront blower fan speed controlFront power MOS FETAirflow volume control dialOff1.0 or lessFront climate control unit: terminal voltage (1P)
1st.Approx. 2.1
2nd.Approx. 2.2
3rd.Approx. 2.3
4th.Approx. 2.4
5th.Approx. 2.5
6th.Approx. 2.7
7th.Approx. 10.7
1SA/CRefrigerant pressure switchFan switch on, A/C switch on1.0 or lessFront climate control unit: terminal voltage (1W, 1X)
Fan switch offB+Wiring harness: continuity, short circuit (Front climate control unit-refrigerant pressure switch: 1S-B) (Refrigerant pressure switch-PCM: C-1B) Refrigerant pressure switch PCM: terminal voltage (1B)
1TRear blower motor feedbackRear power MOS FETRear airflow volume control dialOffApprox. 8.5Wiring harness: continuity, short circuit (Front climate control unit-rear power MOS FET: 1T D, 1V C) Wiring harness: continuity (Rear power MOS FET-body ground: A-ground) Rear power MOS FET Rear blower motor Rear blower relay R.HEATER 40 A fuse
1st.Approx. 6.1
2nd.Approx. 4.8
3rd.Approx. 3.6
4th.Approx. 1.9
5th.1.0 or less
1UOn-board diagnostic signalCheck connectorCheck connector is shorted.1.0 or lessWiring harness: continuity (Front climate control unit-check connector: 1U-A)
OtherB+Wiring harness: short circuit (Front climate control unit-check connector: 1U-A) Front climate control unit: terminal voltage (1W, 1X)
1VRear blower fan speed controlRear power MOS FETRear airflow volume control dialOff1.0 or lessFront climate control unit: terminal voltage (1T)
1st.Approx. 2.1
2nd.Approx. 2.2
3rd.Approx. 2.2
4th.Approx. 2.3
5th.Approx. 2.4
1WIG2A/C 7.5 A fuseIgnition switch is at ON positionB+Wiring harness: continuity, short circuit (Front climate control unit-fuse: 1W-A/C 7.5 A) A/C 7.5 A fuse
Ignition switch is at LOCK position1.0 or less
1XGroundBody groundUnder any condition: Inspect for continuity to ground1.0 or lessWiring harness: continuity (Front climate control unit-ground: 1X-ground)
2AECT sensor signalInstrument clusterBecause this terminal is for communication, good/no good judgment by terminal voltage is not possible.
2B+5VDriver-side front air mix actuator Passenger-side front air mix actuator Front airflow mode actuator Solar radiation sensor Rear air mix actuator Rear airflow mode actuatorUnder any condition5.0Wiring harness: short circuit (Front climate control unit-driver-side front air mix actuator, passenger-side front air mix actuator, front airflow mode actuator, solar radiation sensor, rear air mix actuator, rear airflow mode actuator: 2B-A, A, A, C, A, A) Driver-side front air mix actuator Passenger-side front air mix actuator Front airflow mode actuator Solar radiation sensor Rear air mix actuator Rear airflow mode actuator
2CInformation display signalInformation displayBecause this terminal is for communication, good/no good judgment by terminal voltage is not possible.
2DPotentiometer inputRear airflow mode actuatorTemperature control dial (rear side): Moving towards COLDApprox. 0.5Wiring harness: continuity, short circuit (Front climate control unit-rear airflow mode actuator: 2D-E) Rear airflow mode actuator Front climate control unit: terminal voltage (2B)
Temperature control dial (rear side): Moving towards medium temperatureApprox. 2.4
Temperature control dial (rear side): Moving towards HOTApprox. 4.3
2EPotentiometer inputFront airflow mode actuatorMode switch: Moving towards VENTApprox. 1.0Wiring harness: continuity, short circuit (Front climate control unit-front airflow mode actuator: 2E-E) Front airflow mode actuator Front climate control unit: terminal voltage (2B)
Mode switch: Moving towards BI-LEVELApprox. 1.9
Mode switch: Moving towards HEATApprox. 2.5
Mode switch: Moving towards HEAT/DEFApprox. 3.3
Defroster switch onApprox. 4.0
2FPotentiometer inputDriver-side front air mix actuatorTemperature control dial (driver side): Set temperature at MAX COLD4.0Wiring harness: continuity, short circuit (Front climate control unit-driver-side front air mix actuator: 2F-E) Driver-side front air mix actuator Front climate control unit: terminal voltage (2B)
Temperature control dial (driver side): Set temperature at MAX HOT1.0
2GPotentiometer inputPassenger-side front air mix actuatorTemperature control dial (passenger side): Set temperature at MAX COLD1.0Wiring harness: continuity, short circuit (Front climate control unit-passenger-side front air mix actuator: 2G-E) Passenger-side front air mix actuator Front climate control unit: terminal voltage (2B)
Temperature control dial (passenger side): Set temperature at MAX HOT4.0
2HFront evaporator temperature sensor inputFront evaporator temperature sensorCompared with temperature detected by front evaporator temperature sensorSee scheme 11Wiring harness: continuity (Front climate control unit--front evaporator temperature sensor: 2H-B, 2P-A) Wiring harness: short circuit (Front climate control unit-front evaporator temperature sensor: 2H-B) Front evaporator temperature sensor
21Ambient temperature sensor inputAmbient temperature sensorCompared with temperature detected by ambient temperature sensorSee scheme 14Wiring harness: continuity (Front climate control unit-ambient temperature sensor: 21-B, 2P-A) Wiring harness: short circuit (Front climate control unit-ambient temperature sensor: 21-B) Ambient temperature sensor
2JRear evaporator temperature sensor inputRear evaporator temperature sensorCompared with temperature detected by rear evaporator temperature sensorSee scheme 18Wiring harness: continuity (Front climate control unit-rear evaporator temperature sensor: 2J-B, 2P-A) Wiring harness: short circuit (Front climate control unit-rear evaporator temperature sensor: 2J-B) Rear evaporator temperature sensor
2KCabin temperature sensor inputCabin temperature sensorCompared with temperature detected by cabin temperature sensor(Scheme 50)Wiring harness: continuity (Front climate control unit-cabin temperature sensor: 2K-B, 2P-A) Wiring harness: short circuit (Front climate control unit-cabin temperature sensor: 2K-B) Cabin temperature sensor
2L
2MSolar radiation sensor(LH) inputSolar radiation sensorNatural sunlight shined directly on the solar radiation sensor4.0Wiring harness: continuity (Front climate control unit-solar radiation sensor: 2M-C, 2B-A) Front climate control unit: terminal voltage (2B) Solar radiation sensor
Blocking light to solar radiation sensor1.0 or less
2NPotentiometer inputRear air mix actuatorTemperature control dial (rear side): Set temperature at MAX COLD1.3Wiring harness: continuity, short circuit (Front climate control unit-rear air mix actuator: 2N-E) Rear air mix actuator Front climate control unit: terminal voltage (2B)
Temperature control dial (rear side): Set temperature at MAX HOT4.0
2OSolar radiation sensor (RH) inputSolar radiation sensorNatural sunlight shined directly on the solar radiation sensor4.0Wiring harness: continuity (Front climate control unit-solar radiation sensor: 20-B, 2B-A) Front climate control unit: terminal voltage (2B) Solar radiation sensor
Blocking light to solar radiation sensor1.0 or less
2PSensor groundDriver-side front air mix actuator Passenger-side front air mix actuator Front airflow mode actuator Ambient temperature sensor Cabin temperature sensor Front evaporator temperature sensor Rear air mix actuator Rear airflow mode actuator Rear evaporator temperature sensorUnder any condition: Inspect for continuity to ground1.0 or lessFront climate control unit: terminal voltage (1X)
3A
3B
3CRear climate control unit displayRear climate control unitRear control switch onB+Wiring harness: continuity (Front climate control unit-rear climate control unit: 3C-F)
Rear control switch off1.0 or lessWiring harness: short circuit (Front climate control unit-rear climate control unit: 3C-F) Front climate control unit: terminal voltage (1W, 1X)
3DTNS signalTNS relayTurn the headlight switch to the off position1.0 or lessWiring harness: short circuit (Front climate control unit-TNS relay (main fuse block): 3D-D) ILLUMI 10 A fuse TNS relay Headlight switch
Turn the headlight switch to the TNS positionB+Wiring harness: continuity, short circuit (Front climate control unit-TNS relay (main fuse block): 3D-D) ILLUMI 10 A fuse TNS relay Headlight switch
3ERear fan control volumeRear climate control unitAirflow volume control dialOff1.0 or lessFront climate control unit: terminal voltage (1T) Wiring harness: continuity, short circuit (Front climate control unit-rear climate control unit: 3E-A) Rear climate control unit
1st.Approx. 1.3
Max HIApprox. 4.0
3FTNS signalRear climate control unitTurn the headlight switch to the off position1.0 or lessWiring harness: continuity, short circuit (Front climate control unit-rear climate control unit: 3F-H) TNS relay Headlight switch
Turn the headlight switch to the TNS positionB+
3GRear temperature control volumeRear climate control unitTemperature control dial (rear side): Moving towards COLD1.0 or lessWiring harness: continuity, short circuit (Front climate control unit-rear airflow mode actuator: 3G-C) Rear climate control unit Front climate control unit: terminal voltage (2B)
Temperature control dial (rear side): Moving towards medium temperatureApprox. 2.5
Temperature control dial (rear side): Moving towards HOTApprox. 4.2
3H+5 VRear climate control unitUnder any condition5.0Wiring harness: continuity (Front climate control unit-ground: 3H-ground)
3IGroundRear climate control unitUnder any condition: Inspect for continuity to ground1.0 or lessWiring harness: continuity (Front climate control unit-rear climate control unit: 31-E)
3JPanel light control inputInstrument clusterTurn the headlight switch to the off position1.0 or lessWiring harness: continuity, short circuit (Front climate control unit-instrument cluster: 3J-1I) TNS relay Headlight switch
Turn the headlight switch to the TNS positionB+

TERMINAL VOLTAGE REFERENCE

Scheme 50

Scheme 50

Scheme 51

Scheme 51: REAR CLIMATE CONTROL UNIT REMOVAL/INSTALLATION
  1. Disconnect the negative battery cable.
  2. Remove the console cover. See «CONSOLE COVER REMOVAL/INSTALLATION»(ref-345331-S33051633072009102000000) .
  3. Remove the rear cooler duct. See «REAR COOLER DUCT REMOVAL/INSTALLATION»(ref-345376-S20752728562009102000000) .
  4. Remove the screws.
  5. Remove the rear climate control unit.
  6. Install in the reverse order of removal.

REAR CLIMATE CONTROL UNIT INSPECTION

  1. Connect the rear climate control unit connector.
  2. Turn the ignition switch to the ON position.
  3. Connect the negative (-) lead of the tester to body ground.
  4. By inserting the positive (+) lead of the tester into each rear climate control unit terminal, measure the voltage according to the terminal voltage table. If there is any malfunction, inspect the parts under "Inspection item (s)". If the parts under "Inspection item (s)" are found to be normal, replace the rear climate control unit.

Scheme 52

Scheme 52: Terminal voltage table (Reference)
TerminalSignal nameConnected toMeasurement conditionVoltage (V)Inspection item (s)
ARear fan control volumeFront climate control unitAirflow volume control dialOff1.0 or lessFront climate control unit: terminal voltage (1T) Wiring harness: continuity, short circuit (Front climate control unit-rear climate control unit: 3E-A) Rear climate control unit
1st.Approx. 1.3
Max HIApprox. 4.0
B
CRear temperature control volumeFront climate control unitTemperature control dial: Moving towards COLD1.0 or lessWiring harness: continuity, short circuit (Front climate control unit-rear airflow mode actuator: 3G-C) Rear climate control unit Front climate control unit: terminal voltage (2B)
Temperature control dial: Moving towards medium temperatureApprox. 2.5
Temperature control dial: Moving towards HOTApprox. 4.2
D+5VFront climate control unitUnder any condition5.0Front climate control unit: terminal voltage (3H) Wiring harness: continuity (Front climate control unit-rear climate control unit: 3H-D)
EGroundFront climate control unitUnder any condition: Inspect for continuity to ground1.0 or lessWiring harness: continuity (Front climate control unit-rear climate control unit: 31-E)
FRear climate control unit displayFront climate control unitRear control switch onB+Wiring harness: continuity (Front climate control unit-rear climate control unit: 3C-F)
Rear control switch off1.0 or lessWiring harness: short circuit (Front climate control unit-rear climate control unit: 3C-F) Front climate control unit: terminal voltage (1W, 1X)
GPanel light control inputInstrument clusterTurn the headlight switch to the off position1.0 or lessWiring harness: continuity, short circuit (Rear climate control unit-instrument cluster: G-1I) TNS relay Headlight switch
Turn the headlight switch to the TNS positionB+
HTNS signalFront climate control unitTurn the headlight switch to the off position1.0 or lessWiring harness: continuity, short circuit (Front climate control unit-rear climate control unit: 3F-H) TNS relay Headlight switch
Turn the headlight switch to the TNS positionB+
I
J

TERMINAL VOLTAGE REFERENCE