A/C AMPLIFIER INSPECTION [MANUAL AIR CONDITIONER]


id0740a2318900

1.  Switch the ignition to ON.

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

3.  By inserting the positive (+) lead of the tester into each A/C amplifier 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 A/C amplifier.


Terminal Voltage Table (Reference)

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Terminal

Signal name

Connected to

Measured condition

Voltage (V)

Inspection item(s)

1A
1B
1C
1D
Version signal
Body ground
Under any condition
1.0 or less
•  Related wiring harness
1E
Blower motor feedback
•  Resistor
•  Fan switch
Fan stopped
B+
1.  Related wiring harness
2.  Resistor
3.  Fan switch
4.  Blower motor
5.  Blower relay
6.  A/C 10 A fuse
7.  HEATER 40 A fuse
Fan switch: 1st
0.3
Fan switch: 2nd
1.5
Fan switch: 3rd
1.3
Fan switch: 4th
0.7
1F
1G
1H
1I
Motor operation
Air intake actuator
Switched to RECIRCULATE
1.0 or less
•  Related wiring harness
•  Air intake actuator
Switched to FRESH
B+
1J
Motor operation
Air intake actuator
Switched to RECIRCULATE
B+
•  Related wiring harness
•  Air intake actuator
Switched to FRESH
1.0 or less
1K
Rear window defroster operation
Rear window defroster relay
Rear window defroster switch OFF
B+
•  Related wiring harness
•  Rear window defroster relay
Rear window defroster switch ON
1.0 or less
•  A/C amplifier: terminal voltage (2C, 2L)
1L
1M
A/C
Refrigerant pressure switch
Fan stopped
B+
•  Related wiring harness
•  Refrigerant pressure switch
•  PCM: terminal voltage (1AU)
Fan switch: ON and A/C switch: ON
1.0 or less
•  A/C amplifier: terminal voltage (2C, 2L)
1N
1O
1P
Serial signal
Climate control unit
Terminal used for communication therefore determination based on terminal voltage inspection not possible. Only inspect for an open or short circuit in wiring harness between A/C amplifier terminal 1P and climate control unit terminal K.
•  Related wiring harness
1Q
1R
Serial signal
Climate control unit
Terminal used for communication therefore determination based on terminal voltage inspection not possible. Only inspect for an open or short circuit in wiring harness between A/C amplifier terminal 1R and climate control unit terminal I.
•  Related wiring harness
1S
1T
1U
Motor operation
Air mix actuator
Moving towards COLD
1.0 or less
•  Related wiring harness
•  Air mix actuator
Moving towards HOT
B+
1V
Motor operation
Air mix actuator
Moving towards COLD
B+
•  Related wiring harness
•  Air mix actuator
Moving towards HOT
1.0 or less
1W
Motor operation
Airflow mode actuator
Switched to DEFROSTER
B+
•  Related wiring harness
•  Airflow mode actuator
Switched to VENT
1.0 or less
1X
Motor operation
Airflow mode actuator
Switched to DEFROSTER
1.0 or less
•  Related wiring harness
•  Airflow mode actuator
Switched to VENT
B+
2A
B+
ROOM 10 A fuse
Under any condition
B+
•  Related wiring harness
•  ROOM 10 A fuse
2B
2C
IG2
A/C 10 A fuse
IG SW ON
B+
•  Related wiring harness
•  A/C 10 A fuse
IG SW LOCK
1.0 or less
•  Related wiring harness
2D
Potentiometer input
Air mix actuator
Set temperature at MAX COLD
3.9
•  Related wiring harness
•  Air mix actuator
•  A/C amplifier: terminal voltage (2P)
Set temperature at MAX HOT
1.1
2E
2F
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
•  A/C amplifier: terminal voltage (2C, 2L)
2G
Potentiometer input
Airflow mode actuator
VENT
4.0
•  Related wiring harness
•  Airflow mode actuator
•  A/C amplifier: terminal voltage (2P)
BI-LEVEL
3.3
HEAT
2.6
HEAT/DEF
1.8
DEFROSTER
1.0
2H
2I
2J
2K
2L
GND
Body ground
Under any condition
1.0 or less
•  Related wiring harness
2M
Ambient temperature sensor input
Ambient temperature sensor
Compared with temperature detected by ambient temperature sensor
Refer to graph 2
•  Related wiring harness
•  Ambient temperature sensor
•  A/C amplifier: terminal voltage (2C, 2L)
2N
Sensor GND
•  Ambient temperature sensor
•  Evaporator temperature sensor
•  Air mix actuator
•  Airflow mode actuator
Under any condition
1.0 or less
•  A/C amplifier: terminal voltage (2L)
2O
ECT sensor input
PCM
Compared with temperature detected by ECT sensor
Refer to graph 3
•  Related wiring harness
•  ECT sensor
•  A/C amplifier: terminal voltage (2C, 2L)
2P
+5 V
•  Air mix actuator
•  Airflow mode actuator
IG SW ON
5.0
•  Related wiring harness
•  Air mix actuator
•  Airflow mode actuator
•  A/C amplifier: terminal voltage (2C, 2L)
IG SW LOCK
1.0 or less
•  A/C amplifier replacement