AIR CONDITIONING SYSTEM TERMINALS OF ECU


  1. CHECK AIR CONDITIONING AMPLIFIER ASSEMBLY (except 5L-E)

    A01BG8BE01
    Terminal No. (Symbols) Wiring Color Tester Description Condition Specification
    H18-2 (PTC2) - H18-29 (GND)*1 LG - W-B PTC heater control signal

    Ignition switch ON

    Temperature switch: Max. HOT

    Coolant temperature: Below 76°C (169°F)

    Ambient temperature: Below 10°C (50°F)

    PTC heater: Not operate → Operate (ALT, F-DUTY more than 95%)

    		 Below 1 V → 11 to 14 V
    H18-3 (PTC1) - H18-29 (GND)*1 GR - W-B PTC heater permission signal

    Ignition switch ON

    Temperature switch: Max. HOT

    Coolant temperature: Below 73°C (163°F)

    Ambient temperature: Below 10°C (50°F)

    PTC heater: Not operate → Operate (ALT, F-DUTY more than 95%)

    		 Below 1 V → 11 to 14 V
    H18-4 (PRE) - H18-29 (GND) R - W-B Pressure sensor signal

    Start engine

    Operate air conditioning system

    Refrigerant pressure: Abnormal pressure (More than 3,030 kPa (31.0 kgf/cm, 440 psi))

    		 4.7 V or higher
    H18-4 (PRE) - H18-29 (GND) R - W-B Pressure sensor signal

    Start engine

    Operate air conditioning system

    Refrigerant pressure: Abnormal pressure (less than 180 kPa (1.9 kgf/cm, 27 psi))

    		 Below 0.7 V
    H18-4 (PRE) - H18-29 (GND) R - W-B Pressure sensor signal

    Start engine

    Operate air conditioning system

    Refrigerant pressure: Normal pressure (less than 3,030 kPa (31.0 kgf/cm, 440 psi) and more than 180 kPa (1.9 kgf/cm, 27 psi))

    		 0.7 to 4.7 V
    H18-5 (HEAT) - H18-29 (GND)*5 L - W-B Idle-up switch signal

    Ignition switch ON

    Idle-up switch off → ON

    		 11 to 14 V → Below 1 V
    H18-5 (HEAT) - H18-29 (GND)*2 L - W-B Heater switch signal

    Ignition switch ON

    Heater switch off → ON

    		 11 to 14 V → Below 1 V
    H18-6 (HLS) - H18-29 (GND)*1 R - W-B Headlight dimmer switch signal

    Ignition switch ON

    Headlight dimmer switch: off → ON

    		 Below 1 V → 11 to 14 V
    H18-7 (RCON) - Body ground*3 P - Body ground Rear blower switch signal

    Ignition switch ON

    A/C switch off → ON

    		 Below 1 V → 11 to 14 V
    H18-8 (A/CS) - H18-29 (GND) Y - W-B A/C switch signal

    Ignition switch ON

    Blower switch ON

    A/C switch off → ON

    		 Below 1 V → 11 to 14 V
    H18-9 (LED+) - H18-29 (GND) G - W-B A/C switch indicator signal

    Ignition switch ON

    Blower switch ON

    A/C switch off → ON

    		 Below 1 V → 11 to 14 V
    H18-10 (CANH) R CAN communication system - -
    H18-11 (CANL) W CAN communication system - -
    H18-12 (SG) - Body ground L - Body ground Ground for each sensor Always Below 1 Ω
    H18-13 (S5) - H13-12 (SG) Y - L Power supply for pressure sensor Ignition switch off → ON Below 1 V → 5.15 V
    H18-15 (HTR1) - H18-29 (GND)*2 R - W-B Heater switch indicator signal

    Ignition switch ON

    Heater switch off→ ON

    		 Below 1 V → 11 to 14 V
    H18-16 (BLW) - H18-29 (GND) GR - W-B Blower motor control signal

    Ignition switch ON

    Blower switch off → ON

    		 11 to 14 V → Below 1 V
    H18-17 (HT-2) - Body ground*2 B - Body ground Magnetic valve signal

    Start engine

    Operate air conditioning system

    Temperature switch: Max. HOT

    Coolant temperature: Below 65°C (149°F)

    HOT Gas heater: Operate → Not operate

    		 Below 1 V → 11 to 14 V
    H18-18 (RMGV) - Body ground*3 Y - Body ground Rear magnetic valve signal

    Ignition switch ON

    Rear magnetic valve off → ON

    		 11 to 14 V → Below 1 V
    H18-19 (MGC) - Body ground*4 V - Body ground Magnet clutch ON permission signal

    Ignition switch ON

    A/C switch off → ON

    		 11 to 14 V → Below 1 V
    H18-19 (MGC) - Body ground*6 V - Body ground Compressor assembly with pulley operation signal

    Engine running

    Blower switch LO

    A/C switch ON

    Pulse generation

    (See waveform 2)
    H18-20 (IG+) - Body ground R - Body ground Power source (IG) Ignition switch off → ON Below 1 V → 11 to 14 V
    H18-21 (PO1) - H18-29 (GND)*7 V - W-B No. 2 air conditioner pressure sensor signal

    Start engine

    Operate air conditioning system

    Refrigerant pressure: Abnormal pressure (More than 3,030 kPa (31.0 kgf/cm, 440 psi))

    		 4.7 V or higher
    H18-21 (PO1) - H18-29 (GND)*7 V - W-B No. 2 air conditioner pressure sensor signal

    Start engine

    Operate air conditioning system

    Refrigerant pressure: Abnormal pressure (less than 180 kPa (1.9 kgf/cm, 27 psi))

    		 Below 0.7 V
    H18-21 (PO1) - H18-29 (GND)*7 V - W-B No. 2 air conditioner pressure sensor signal

    Start engine

    Operate air conditioning system

    Refrigerant pressure: Normal pressure (less than 3,030 kPa (31.0 kgf/cm, 440 psi) and more than 180 kPa (1.9 kgf/cm, 27 psi))

    		 0.7 to 4.7 V
    H18-22 (B/LV) - H18-31 (SG-1) B - B Room compartment temperature set signal Max. HOT → Max. COOL 0 Ω → 3 kΩ
    H18-23 (TP2) - H18-30 (SG-2)*3 W - L Rear evaporator temperature sensor signal Ignition switch off → ON

    Click here

    H18-24 (TP) - H18-31 (SG-1) W - B Evaporator temperature sensor signal Ignition switch off → ON

    Click here

    H18-28 (LOCK) - H18-31 (SG-1)*4 W - B Compressor lock sensor signal

    Engine idling

    A/C switch ON (Magnet clutch ON)

    Pulse generation

    (See waveform 1)
    H18-29 (GND) - Body ground W-B - Body ground Ground for main power supply Always Below 1 Ω
    H18-30 (SG-2) - Body ground*3 L - Body ground Ground for rear evaporator temperature sensor Always Below 1 Ω
    H18-31 (SG-1) - Body ground B - Body ground Ground for each sensor Always Below 1 Ω
    H18-38 (MH) - Body ground B - Body ground Max. hot switch signal Except max. HOT → Max. HOT Below 1 V → 11 to 14 V
    H18-40 (B) - Body ground W - Body ground Power source (Back-up) Always 11 to 14 V

    • *1: w/ PTC Heater

    • *2: w / Heater Switch

    • *3: w/ Rear Cooler

    • *4: for 1KD-FTV, 2KD-FTV

    • *5: w/ Idle-up Switch

    • *6: for 1TR-FE, 2TR-FE

    • *7: for LHD, 2TR-FE


    1. A01BCT8E12

      Using an oscilloscope, check waveform.

      Waveform 1
      Item Content
      Terminal No. (Symbol) H18-28 (LOCK) - H18-31 (SG-1)*4
      Tool Setting 200 mV/DIV., 10 msec./DIV.
      Condition

      Engine idling

      A/C switch ON (Magnet clutch ON)
    2. A01BCF0E11

      Using an oscilloscope, check waveform.

      Waveform 2
      Item Content
      Terminal No. (Symbol) H18-19 (MGC) - Body ground
      Tool Setting 5 V/DIV., 500 μs/DIV.
      Condition

      Engine running

      Blower switch LO

      A/C switch on

  2. AIR CONDITIONING AMPLIFIER ASSEMBLY (for 5L-E)

    A01BA9SE01
    Terminal No. (Symbol) Wiring Color Tester Description Condition Specification
    H19-8 (AC1) - Body ground B - Body ground Compressor operation signal

    Ignition switch ON

    A/C switch: off → ON

    		 3.7 to 4.5 V → 1.3 to 2.6 V
    H19-10 (ACT) - Body ground G - Body ground Compressor permission signal

    Ignition switch ON

    A/C switch: off → ON

    		 Below 1 V → 11 to 14 V
    H19-11 (A/CS) - H19-6 (GND) Y - W-B A/C switch signal

    Ignition switch ON

    A/C switch: off → ON

    		 Below 1 V → 11 to 14 V
    H19-6 (GND) - Body ground W-B - Body ground Ground for main power supply Always Below 1 Ω
    H19-3 (PRS) - Body ground L - Body ground Pressure switch signal

    Start engine

    Operate air conditioning system

    Refrigerant pressure: Normally → Less than 0.19 MPa (2.0 kgf/cm, 28 psi) or more than 1.34 MPa (13.7 kgf/cm, 195 psi)

    		 Below 1 V → 11 to 14 V
    H19-4 (TE) - H19-16 (SG) W - B Evaporator temperature sensor signal Ignition switch off → ON

    Click here

    H19-16 (SG) - Body ground B - Body ground Ground for each sensor Always Below 1 Ω
    H19-12 (B/LV) - H19-16 (SG) B - L-B Room compartment temperature set signal Max. HOT → Max. COOL 0 Ω → 3 Ω
    H19-7 (TP2) - H19-16 (SG)* W - B Rear evaporator temperature sensor signal Ignition switch off → ON

    Click here

    H19-18 (RCON) - Body ground* P - Body ground Rear blower switch signal

    Ignition switch ON

    A/C switch: off → ON

    		 Below 1 V → 11 to 14 V
    H19-9 (RMGV) - Body ground* Y - Body ground Rear magnetic valve signal

    Ignition switch ON

    Rear magnetic valve: OFF → ON

    		 Below 1 V → 11 to 14 V
    H19-15 (MGC) - Body ground V - Body ground Magnet clutch ON permission signal

    Engine running

    A/C switch: off → ON

    		 Below 1 V → 11 to 14 V
    H19-13 (IG+) - Body ground R - Body ground Power source (IG) Ignition switch off → ON Below 1 V → 11 to 14 V

    • *: w/ Rear Cooler