Mazda 3 Service Manual: Climate Control Unit Inspection [Manual Air Conditioner]

Mazda 3 Service Manual / HVAC / A/C / Climate Control Unit Inspection [Manual Air Conditioner]

1. Remove the climate control unit with the connector connected..

2. Switch the ignition to ON.

3. Connect the negative (-) lead of the tester to the body ground.

4. By inserting the positive (+) lead of the tester into the climate control unit connector, 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 normal, replace the climate control unit.

Terminal Voltage Table (Reference)


Terminal	Signal name	Connected to	Measurement condition	Voltage (V)	Inspection item(s)
1A	―	―	―	―	―
1B	Motor operation	Air intake actuator	Switched to RECIRCULATE	B+	Related wiring harness Air intake actuator
1B	Motor operation	Air intake actuator	Switched to FRESH	1.0 or less	Related wiring harness Air intake actuator
1C	Evaporator temperature sensor input	Evaporator temperature sensor	Compared with temperature detected by evaporator temperature sensor	Refer to graph 1	Related wiring harness Evaporator temperature sensor Climate control unit: terminal voltage (1G)
1D	―	―	―	―	―
1E	―	―	―	―	―
1F	Motor operation	Air intake actuator	Switched to RECIRCULATE	1.0 or less	Related wiring harness Air intake actuator
1F	Motor operation	Air intake actuator	Switched to FRESH	B+	Related wiring harness Air intake actuator
1G	Sensor GND	Evaporator temperature sensor Refrigerant pressure sensor*1	Under any condition	1.0 or less	Related wiring harness Evaporator temperature sensor Refrigerant pressure sensor Climate control unit: terminal voltage (1H)
1H*1	+5 V	Refrigerant pressure sensor	Switch the ignition to ON	5	Related wiring harness Climate control unit: terminal voltage (1G)
1H*1	+5 V	Refrigerant pressure sensor	Switch the ignition to Off	1.0 or less
1I	Ground	Body ground	Under any condition	1.0 or less	Related wiring harness
1J	―	―	―	―	―
1K*2	Fan switch position	Fan switch	Fan switch position 0, 1 and 2	B+	Fan switch
1K*2	Fan switch position	Fan switch	Fan switch position 3 and 4	1.0 or less	Fan switch
1L	Blower fan ON/OFF signal	Fan switch	Fan stopped	B+	Fan switch terminal voltage (D)
1L	Blower fan ON/OFF signal	Fan switch	Fan on	1.0 or less	Fan switch terminal voltage (D)
2A	Illumination (-)	Instrument cluster	Headlight ON and panel light control MAX	2.0	Instrument cluster Related wiring harness
2A	Illumination (-)	Instrument cluster	Headlight ON and panel light control MIN	9.65	Instrument cluster Related wiring harness
2B	B+	ROOM 15 A fuse	Under any condition	B+	Related wiring harness ROOM 15 A fuse
2C	―	―	―	―	―
2D	LIN	BCM	Because this terminal is for communication, good/no good judgement by terminal voltage is not possible.		Related wiring harness BCM
2E	―	―	―	―	―
2F	TNS signal	TNS relay	TNS OFF	1.0 or less	Related wiring harness TNS relay BCM Headlight switch
2F	TNS signal	TNS relay	TNS ON	B+	Related wiring harness TNS relay BCM Headlight switch
2G	―	―	―	―	―
2H	IG2	HEATER 10 A fuse	IG SW ON	B+	Related wiring harness HEATER 10 A fuse
2H	IG2	HEATER 10 A fuse	IG SW LOCK	1.0 or less	Related wiring harness HEATER 10 A fuse
2I	―	―	―	―	―
2J*1	Refrigerant pressure sensor signal	Refrigerant pressure sensor	Compared with temperature detected by refrigerant pressure sensor	(See REFRIGERANT PRESSURE SENSOR INSPECTION [MANUAL AIR CONDITIONER].)	Related wiring harness Refrigerant pressure sensor
2K	Rear window defroster indicator	BCM	Rear window defroster OFF	11.12	Related wiring harness BCM
2K	Rear window defroster indicator	BCM	Rear window defroster ON	1.0 or less	Related wiring harness BCM
2L	―	―	―	―	―
2M	―	―	―	―	―
2N	―	―	―	―	―
2O	Rear window defroster signal	BCM	While pressed rear window defroster switch	1.0 or less	Related wiring harness Rear window defroster switch BCM
2O	Rear window defroster signal	BCM	Released rear window defroster switch	4.7	Related wiring harness Rear window defroster switch BCM
2P	A/C signal	Instrument cluster	A/C ON	1.0 or less	Related wiring harness Instrument cluster
2P	A/C signal	Instrument cluster	A/C OFF	4.8	Related wiring harness Instrument cluster

*1 MZR 2.0, MZR 2.5

*2 SKYACTIV-G 2.0

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