Air Conditioning System (For Manual Air Conditioning System) -- Terminals Of Ecu |
CHECK AIR CONDITIONING AMPLIFIER ASSEMBLY |

Disconnect the G24 and G25 amplifier connectors.
Measure the voltage and resistance according to the value(s) in the table below.
Terminal No. (Symbol) Wiring Color Terminal Description Condition Specified Condition G25-21 (B) - G25-14 (GND) V - W-B Battery power source Always 11 to 14 V G25-1 (IG+) - G25-14 (GND) L - W-B Ignition power supply Ignition switch ON 11 to 14 V Ignition switch off Below 1 V G25-14 (GND) - Body ground W-B - Body ground Ground for main power supply Always Below 1 Ω G24-20 (RGND) - Body ground*1 W-B - Body ground Ground for main power supply Always Below 1 Ω G24-24 (+B2) - G24-20 (RGND)*1 GR - W-B Battery power source Always 11 to 14 V Reconnect the G24 and G25 amplifier connectors.
Measure the voltage and waveform according to the value(s) in the table below.
Terminal No. (Symbol) Wiring Color Terminal Description Condition Specified Condition G25-3 (PTC1) - Body ground*8 V - Body ground PTC NO.1 relay operation signal*9
PTC HTR NO.1 relay operation signal*10- Engine running (1250 rpm or more)
- Temperature setting MAX HOT
- Outside temperature 10°C (50°F) or less
- Engine coolant temperature 79°C (175°F) or less
- Headlight dimmer switch off
- Blower switch off → on
11 to 14 V → Below 1 V G25-4 (PTC3) - Body ground*8 P - Body ground PTC NO.3 relay operation signal*9
PTC HTR NO.3 relay operation signal*10- Engine running (1250 rpm or more)
- Temperature setting MAX HOT
- Outside temperature 10°C (50°F) or less
- Engine coolant temperature 73°C (163°F) or less
- Headlight dimmer switch off
- Blower switch off → on
11 to 14 V → Below 1 V G25-5 (TAM) - G25-13 (SG-2) V - G Cooler thermistor (ambient temperature sensor) signal - Ignition switch ON
- Ambient temperature 25°C (77°F)
1.35 to 1.75 V G25-5 (TAM) - G25-13 (SG-2) V - G Cooler thermistor (ambient temperature sensor) signal - Ignition switch ON
- Ambient temperature 40°C (104°F)
0.9 to 1.2 V G25-8 (LOCK) - G25-13 (SG-2)*2 R - G A/C compressor lock sensor signal - Engine running
- Blower switch LO
- A/C switch on (magnet clutch on)
Pulse generation
(See waveform 1)G25-9 (PRE) - G25-13 (SG-2)*3 G - G Air conditioner pressure sensor signal - Ignition switch ON
- Refrigerant pressure normal (below 3.025 MPa [30.9 kgf/cm2, 438.6 psi] and higher than 0.176 MPa [1.8 kgf/cm2, 25.5 psi])
0.63 to 4.72 V G25-9 (PRE) - G25-13 (SG-2)*3 G - G Air conditioner pressure sensor signal - Ignition switch ON
- Refrigerant pressure abnormal (below 0.176 MPa [1.8 kgf/cm2, 25.5 psi])
Below 0.63 V G25-9 (PRE) - G25-13 (SG-2)*3 G - G Air conditioner pressure sensor signal - Ignition switch ON
- Refrigerant pressure abnormal (higher than 3.025 MPa [30.9 kgf/cm2, 438.6 psi])
4.72 V or higher G25-9 (PRE) - Body ground*4 G - Body ground No. 1 pressure switch signal - Ignition switch ON
- Refrigerant pressure normal (below 3.14 MPa [32.0 kgf/cm2, 455 psi] and higher than 0.196 MPa [2.0 kgf/cm2, 28 psi])
Below 1 V G25-9 (PRE) - Body ground*4 G - Body ground No. 1 pressure switch signal - Ignition switch ON
- Refrigerant pressure abnormal (below 0.196 MPa [2.0 kgf/cm2, 28 psi] or higher than 3.14 MPa [32.0 kgf/cm2, 455 psi])
4.69 V or higher G25-10 (S5-3) - G25-13 (SG-2) B - G Power supply for air conditioner pressure sensor Ignition switch ON 4.75 to 5.25 V G25-15 (COOL) - G25-14 (GND)*5 V - W-B Cooling box assembly operation signal - Engine running
- Cooler control switch sub-assembly on
Below 1 V G25-16 (MG+) - G25-14 (GND)*7 V - W-B Viscous with magnetic clutch heater assembly operation signal - Engine running
- Power heater switch on
Below 1 V G25-17 (AC1) - G25-14 (GND) LG - W-B Compressor operation signal - Engine running
- Blower switch LO
- A/C switch off
11 to 14 V - Engine running
- Blower switch LO
- A/C switch on
Below 1 V G25-18 (HTR1) - G25-14 (GND) G - W-B Engine operating signal Engine idling 11 to 14 V G25-20 (MGC) - G25-14 (GND) R - W-B Magnet clutch assembly operation signal - Engine running
- A/C switch off → on
- Blower switch LO
- Magnet clutch assembly off → on
11 to 14 V → Below 1 V G25-22 (PTC2) - Body ground*8 LG - Body ground PTC NO.2 relay operation signal*9
PTC HTR NO.2 relay operation signal*10- Engine running (1250 rpm or more)
- Temperature setting MAX HOT
- Outside temperature 10°C (50°F) or less
- Engine coolant temperature 76°C (169°F) or less
- Headlight dimmer switch off
- Blower switch off → on
11 to 14 V → Below 1 V G25-23 (BLW) - G25-14 (GND) L - W-B Blower with fan motor sub-assembly control signal - Ignition switch ON
- Blower switch LO
Pulse generation
(See waveform 2)G25-25 (ALT) - G25-14 (GND)*8 L - W-B Generator signal (PTC heater control) Engine started Pulse generation G25-27 (ACT) - G25-14 (GND) R - W-B Compressor operation signal - Engine running
- Blower switch LO
- A/C switch off (magnet clutch off)
Below 1 V - Engine running
- Blower switch LO
- A/C switch on (magnet clutch on)
4.75 to 5.25 V G25-36 (SWVC) - G25-14 (GND)*6 W - W-B Idle up switch operation signal - Ignition switch ON
- Idle up switch on
Below 1 V G25-36 (SWVC) - G25-14 (GND)*7 W - W-B Heater switch assembly operation signal - Ignition switch ON
- Heater switch assembly on
Below 1 V G25-37 (LIN1) - Body ground P - Body ground LIN communication signal Ignition switch ON Pulse generation G24-1 (RBUS) - G24-21 (RBUG)*1 LG - L BUS IC control signal (for Rear) Ignition switch ON Pulse generation G24-4 (TEC) - G24-19 (SGND)*1 SB - V Rear evaporator temperature sensor signal - Ignition switch ON
- Rear evaporator temperature 0°C (32°F)
2.0 to 2.4 V - Ignition switch ON
- Rear evaporator temperature: 15°C (59°F)
1.4 to 1.8 V G24-12 (SWCB) - G25-14 (GND)*5 LG - W-B Cooling box assembly operation signal - Engine running
- A/C switch on
- Cooler control switch sub-assembly on
Below 1 V G24-13 (RLIN) - Body ground*1 L - Body ground LIN communication signal Ignition switch ON Pulse generation G24-19 (SGND) - Body ground*1 V - Body ground Ground for rear evaporator temperature sensor Always Below 1 V G24-20 (RGND) - Body ground*1 W-B - Body ground Ground for power supply Always Below 1 V G24-22 (BLWH) - G24-20 (RGND)*1 W - W-B Rear blower with fan motor sub-assembly control signal - Ignition switch ON
- Rear blower switch on
Pulse generation
(See waveform 3)G24-23 (RBBU) - G24-21 (RBUG)*1 P - L Power supply for BUS IC (for Rear) Always 11 to 14 V z1-2 (BUS G) - Body ground - Ground for BUS IC Always Below 1 V z1-3 (BUS) - z1-2 (BUS G) - BUS IC control signal Ignition switch ON Pulse generation z1-4 (B BUS) - z1-2 (BUS G) - Power supply for BUS IC Always 11 to 14 V z1-6 (TEA) - z1-5 (SGA) - No. 1 cooler thermistor signal - Ignition switch ON
- Evaporator temperature 0°C (32°F)
1.7 to 2.1 V - Ignition switch ON
- Evaporator temperature 15°C (59°F)
0.9 to 1.3 V - *1: w/ Rear Air Conditioning System
- *2: except 5L-E
- *3: for Sensor Type
- *4: for Switch Type
- *5: w/ Refrigerated Cool Box
- *6: w/ Idle Up Switch
- *7: w/ Viscous Heater
- *8: w/ PTC Heater
- *9: w/o Urea SCR System
- *10: w/ Urea SCR System
- Engine running (1250 rpm or more)
Using an oscilloscope, check waveform 1.
A/C Compressor Lock Sensor Signal Item Content Terminal No. (Symbol) G25-8 (LOCK) - G25-14 (GND) Tool Setting 200 mV/DIV., 10 ms./DIV. Condition - Engine running
- Blower switch LO
- A/C switch on (magnet clutch on)
- Engine running
Using an oscilloscope, check waveform 2.
Blower Motor Control Signal Item Content Terminal No. (Symbol) G25-23 (BLW) - H46-14 (GND) Tool Setting 1 V/DIV., 500 μs/DIV. Condition - Ignition switch ON
- Blower switch LO
- HINT:
- When the blower level is increased, the duty ratio changes accordingly.
- Ignition switch ON
Using an oscilloscope, check waveform 3.
Blower Motor Control Signal Item Content Terminal No. (Symbol) G24-22 (BLWH) - G24-20 (RGND) Tool Setting 2 V/DIV., 500 μs/DIV. Condition - Ignition switch ON
- Blower switch LO
- HINT:
- When the blower level is increased, the duty ratio changes accordingly.
- Ignition switch ON
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CHECK AIR CONDITIONING AMPLIFIER ASSEMBLY (FOR COOLING BOX) (w/ Refrigerated Cool Box) |

Disconnect the air conditioning amplifier (for cooling box) connectors.
Measure the voltage according to the value(s) in the table below.
Terminal No. (Symbol) Wiring Color Terminal Description Condition Specified Condition 1 (+B) - 4 (GND) W-R - W-B Battery power source Always 11 to 14 V 2 (IG+) - 4 (GND) GR - W-B IG power supply Ignition switch ON 11 to 14 V Ignition switch off Below 1 V Reconnect the air conditioning amplifier (for cooling box) connectors.
Measure the resistance and voltage according to the value(s) in the table below.
Terminal No. (Symbol) Wiring Color Terminal Description Condition Specified Condition 5 (SW) - 4 (GND) LG-R - W-B Cooler control switch sub-assembly operation signal - Engine running
- Cooler control switch on
Below 1 V 6 (CBI) - 4 (GND) L-G - W-B Cooler compressor permission signal - Engine running
- Cooler control switch sub-assembly on
Below 1 V 7 (LED) - 4 (GND) L-B - W-B Cooling box indicator signal - Engine running
- Cooler control switch sub-assembly on
Below 1 V 8 (CBT) - 4 (GND) BR-Y - W-B Air conditioning amplifier assembly request signal - Engine running
- Cooler control switch sub-assembly on
Below 1 V 9 (BLW) - 4 (GND) W - W-B No. 1 cooler blower motor sub-assembly operation signal - Engine running
- Cooler control switch sub-assembly on
Below 1 V 10 (SG) - 4 (GND) W-L - W-B Ground Always Below 1 Ω - Engine running
CHECK INTEGRATION CONTROL AND PANEL ASSEMBLY |

Disconnect the G23 panel connector.
Measure the resistance and voltage according to the value(s) in the table below.
Terminal No. (Symbol) Wiring Color Terminal Description Condition Specified Condition G23-1 (+B) - G23-4 (GND) L - W-B Battery power source Always 11 to 14 V G23-5 (IG) - G23-4 (GND) L - W-B IG power supply Ignition switch ON 11 to 14 V Ignition switch off Below 1 V G23-6 (ACC) - G23-4 (GND) P - W-B ACC power supply Ignition switch ACC 11 to 14 V Ignition switch off Below 1 V G23-4 (GND) - Body ground W-B - Body ground Ground Always Below 1 Ω Reconnect the G23 panel connector.
Measure the waveform according to the value(s) in the table below.
Terminal No. (Symbol) Wiring Color Terminal Description Switch Condition Specified Condition G23-3 (LIN1) - Body ground P - Body ground LIN communication signal Ignition switch ON Pulse generation
CHECK AIR CONDITIONING CONTROL ASSEMBLY (w/ Rear Air Conditioning System, w/o Rear Seat Heater) |

Disconnect the T3 control connector.
Measure the resistance and voltage according to the value(s) in the table below.
Terminal No. (Symbol) Wiring Color Terminal Description Condition Specified Condition T3-5 (IG) - T3-8 (E) L - W-B IG power supply Ignition switch ON 11 to 14 V Ignition switch off Below 1 V T3-8 (E) - Body ground W-B - Body ground Ground Always Below 1 Ω Reconnect the T3 control connector.
Measure the waveform according to the value(s) in the table below.
Terminal No. (Symbol) Wiring Color Terminal Description Switch Condition Specified Condition T3-3 (RLIN) - Body ground L - Body ground LIN communication signal Ignition switch ON Pulse generation
CHECK AIR CONDITIONING CONTROL ASSEMBLY (w/ Rear Air Conditioning System, w/ Rear Seat Heater) |

Disconnect the T7 control connector.
Measure the resistance and voltage according to the value(s) in the table below.
Terminal No. (Symbol) Wiring Color Terminal Description Condition Specified Condition T7-1 (IG) - T7-8 (E) L - W-B IG power supply Ignition switch ON 11 to 14 V Ignition switch off Below 1 V T7-8 (E) - Body ground W-B - Body ground Ground Always Below 1 Ω Reconnect the T7 control connector.
Measure the waveform according to the value(s) in the table below.
Terminal No. (Symbol) Wiring Color Terminal Description Switch Condition Specified Condition T7-6 (RLIN) - Body ground L - Body ground LIN communication signal Ignition switch ON Pulse generation