AIR CONDITIONING SYSTEM(for Manual Air Conditioning System) TERMINALS OF ECU


  1. CHECK AIR CONDITIONING AMPLIFIER ASSEMBLY (w/ Cooler)

    A01VGRZE02

    Tech Tips

    Check from the rear of the connector while it is connected to the air conditioning amplifier assembly.

    Terminal No. (Symbol) Wiring Color Terminal Description Condition Specified Condition
    F41-1 (IG+) - F41-23 (GND) V - W-B Ignition power supply Ignition switch: ON 11 to 14 V
    F41-2 (A/C) - F41-23 (GND) G - W-B A/C switch signal Ignition switch: ON Below 1 V → 11 to 14 V
    Defroster: OFF
    A/C switch: OFF → ON
    F41-3 (HEAT) - Body ground*1 LG - Body ground MAX HOT switch detection signal Ignition switch: ON 11 to 14 V
    No. 3 heater control knob: MAX HOT
    F41-4 (TE) - F41-15 (SG- 1) GR - B Evaporator temperature sensor signal Ignition switch: ON 1.0 to 1.3 V
    Temperature near evaporator: 15°C (59°F)
    F41-5 (SG-2) - Body ground L - Body ground Ground for A/ C pressure sensor Always Below 1 Ω
    F41-7 (PRE) - F41-23 (GND) GR - W-B A/C pressure sensor signal Refrigerant pressure: Normal 0.74 to 4.62 V

    Refrigerant pressure: Abnormal

    (less than 0.176 MPaG [1.8 kgf/cm2] or more than 3.03 MPaG [31 kgf/cm2])

    		 Below 0.74 V or 4.62 V or more
    F41-8 (TX+) - F41-23 (GND) V - W-B CAN communication signal Ignition switch: ON

    Pulse generation

    (See waveform 1)
    F41-9 (TX-) - F41-23 (GND) W - W-B CAN communication signal Ignition switch: ON

    Pulse generation

    (See waveform 2)
    F41-11 (SOL+) - F41-23 (GND) P - W-B A/C compressor operation signal Engine idling

    Pulse generation

    (See waveform 3)
    Blower switch: 1
    A/C switch: ON
    F41-13 (PTC1) - Body ground*1 SB - Body ground Quick heater assembly relay operation signal Engine idling 11 to 14 V → Below 1 V
    No. 3 heater control knob: MAX HOT
    Engine coolant temperature: Below 75°C (167°F)
    Ambient temperature: Below 10°C (50°F)
    Blower switch: 0 → 1
    Waiting time: 10 seconds
    F41-14 (HR) - Body ground R - Body ground Heater blower motor relay operation signal Ignition switch: ON 11 to 14 V → Below 1 V
    Blower switch: 0 → 1
    F41-15 (SG-1) - Body ground B - Body ground Ground for evaporator temperature sensor Always Below 1 Ω
    F41-16 (LED) - Body ground BE - Body ground A/C switch indicator signal Engine idling 11 to 14 V → Below 4 V
    A/C switch: ON
    Blower switch: 0 → 1
    F41-17 (SBLW) - Body ground GR - Body ground Blower motor ON signal Ignition switch: ON 11 to 14 V → Below 1 V
    Blower switch: 0 → 1
    F41-19 (PTC2) - Body ground*1 P - Body ground Quick heater assembly relay operation signal Engine idling 11 to 14 V → Below 1 V
    No. 3 heater control knob: MAX HOT
    Engine coolant temperature: Below 70°C (158°F)
    Ambient temperature: Below 10°C (50°F)
    Blower switch: 0 → 1
    Waiting time: 20 seconds
    F41-20 (PTC3) - Body ground*1 V - Body ground Quick heater assembly relay operation signal Engine idling 11 to 14 V → Below 1 V
    No. 3 heater control knob: MAX HOT
    Engine coolant temperature: Below 65°C (149°F)
    Ambient temperature: Below 10°C (50°F)
    Blower switch: 0 → 1
    Waiting time: 30 seconds
    F41-21 (HLS) - Body ground*1 R - Body ground Headlight signal

    Engine idling

    Head light switch: OFF → ON

    		 11 to 14 V → Below 1 V
    F41-23 (GND) - Body ground W-B - Body ground Ground for main power supply Always Below 1 Ω
    F41-24 (S5-3) - F41-23 (GND) Y - W-B Power supply for pressure sensor Ignition switch: ON 4.75 to 5.25 V

    • *1: w/ PTC Heater

    • If the result is not as specified, there may be a malfunction in the wire harness.


    1. A01VKSXE99
      *a 1 V/DIV.
      *b 10 μsec./DIV.

      Waveform 1 (Reference) : Using an oscilloscope

      CAN Communication Signal
      Terminal Name F41-8 (TX+) - F41-23 (GND)
      Tester Range 1 V / DIV., 10 μsec. / DIV.
      Condition Ignition switch ON

      Tech Tips

      The waveform varies depending on the CAN communication signal.

    2. A01VKJKE92
      *a 1 V/DIV.
      *b 10 μsec./DIV.

      Waveform 2 (Reference) : Using an oscilloscope

      CAN Communication Signal
      Terminal Name F41-9 (TX-) - F41-23 (GND)
      Tester Range 1 V / DIV., 10 μsec. / DIV.
      Condition Ignition switch ON

      Tech Tips

      The waveform varies depending on the CAN communication signal.

    3. A01VKGIE26
      *a 5 V/DIV.
      *b 500 μsec/DIV.

      Waveform 3: Using an oscilloscope

      Compressor and Pulley Operation Signal
      Terminal Name F41-11 (SOL+) - F41-23 (GND)
      Tester Range 5 V / DIV., 500 μsec. / DIV.
      Condition

      Engine idling

      Blower switch 1

      A/C switch ON

  2. CHECK COMBINATION METER ASSEMBLY (w/ Cooler)

    A01VJCDE02

    Tech Tips

    Check from the rear of the connector while it is connected to the combination meter assembly.

    Terminal No. (Symbol) Wiring Color Terminal Description Condition Specified Condition
    F1-34 (TX1-) - Body ground B - Body ground Ground for ambient temperature sensor Always Below 1 Ω
    F1-35 (TX1+) - F1-34 (TX1-) W - B Ambient temperature sensor signal Ignition switch ON at 25°C (77°F) 1.35 to 1.75 V
    F1-39 (IG+) - Body ground P - Body ground Ignition power supply Ignition switch ON 11 to 14 V
    F1-40 (B) - Body ground L - Body ground Battery power supply Always 11 to 14 V

    • If the result is not as specified, there may be a malfunction in the wire harness.

  3. CHECK AIR CONDITIONING AMPLIFIER ASSEMBLY (w/o Cooler)

    A01VGRZE02

    Tech Tips

    Check from the rear of the connector while it is connected to the air conditioning amplifier assembly.

    Terminal No. (Symbol) Wiring Color Terminal Description Condition Specified Condition
    F41-1 (IG+) - F41-23 (GND)*1 V - W-B Ignition power supply Ignition switch: ON 11 to 14 V
    F41-3 (HEAT) - Body ground*1 LG - Body ground MAX HOT switch detection signal Ignition switch: ON 11 to 14 V
    No. 3 heater control knob: MAX HOT
    F41-8 (TX+) - F41-23 (GND)*1 V - W-B CAN communication signal Ignition switch: ON

    Pulse generation

    (See waveform 1)
    F41-9 (TX-) - F41-23 (GND)*1 W - W-B CAN communication signal Ignition switch: ON

    Pulse generation

    (See waveform 2)
    F41-13 (PTC1) - Body ground*1 SB - Body ground Quick heater assembly relay operation signal Engine idling 11 to 14 V → Below 1 V
    No. 3 heater control knob: MAX HOT
    Engine coolant temperature: Below 75°C (167°F)
    Ambient temperature: Below 10°C (50°F)
    Blower switch: 0 → 1
    Waiting time: 10 seconds
    F41-14 (HR) - Body ground R - Body ground Heater blower motor relay operation signal Ignition switch: ON 11 to 14 V → Below 1 V
    Blower switch: 0 → 1
    F41-17 (SBLW) - Body ground GR - Body ground Blower motor ON signal Ignition switch: ON 11 to 14 V → Below 1 V
    Blower switch: 0 → 1
    F41-19 (PTC2) - Body ground*1 P - Body ground Quick heater assembly relay operation signal Engine idling 11 to 14 V → Below 1 V
    No. 3 heater control knob: MAX HOT
    Engine coolant temperature: Below 70°C (158°F)
    Ambient temperature: Below 10°C (50°F)
    Blower switch: 0 → 1
    Waiting time: 20 seconds
    F41-20 (PTC3) - Body ground*1 V - Body ground Quick heater assembly relay operation signal Engine idling 11 to 14 V → Below 1 V
    No. 3 heater control knob: MAX HOT
    Engine coolant temperature: Below 65°C (149°F)
    Ambient temperature: Below 10°C (50°F)
    Blower switch: 0 → 1
    Waiting time: 30 seconds
    F41-21 (HLS) - Body ground*1 R - Body ground Headlight signal

    Engine idling

    Head light switch: OFF → ON

    		 11 to 14 V → Below 1 V
    F41-23 (GND) - Body ground*1 W-B - Body ground Ground for main power supply Always Below 1 Ω

    • *1: w/ PTC Heater

    • If the result is not as specified, there may be a malfunction in the wire harness.


    1. A01VKSXE99
      *a 1 V/DIV.
      *b 10 μsec./DIV.

      Waveform 1 (Reference) : Using an oscilloscope

      CAN Communication Signal
      Terminal Name F41-8 (TX+) - F41-23 (GND)
      Tester Range 1 V / DIV., 10 μsec. / DIV.
      Condition Ignition switch ON

      Tech Tips

      The waveform varies depending on the CAN communication signal.

    2. A01VKJKE92
      *a 1 V/DIV.
      *b 10 μsec./DIV.

      Waveform 2 (Reference) : Using an oscilloscope

      CAN Communication Signal
      Terminal Name F41-9 (TX-) - F41-23 (GND)
      Tester Range 1 V / DIV., 10 μsec. / DIV.
      Condition Ignition switch ON

      Tech Tips

      The waveform varies depending on the CAN communication signal.

  4. CHECK COMBINATION METER ASSEMBLY (w/o Cooler)

    A01VJCDE02

    Tech Tips

    Check from the rear of the connector while it is connected to the combination meter assembly.

    Terminal No. (Symbol) Wiring Color Terminal Description Condition Specified Condition
    F1-34 (TX1-) - Body ground*1 B - Body ground Ground for ambient temperature sensor Always Below 1 Ω
    F1-35 (TX1+) - F1-34 (TX1-)*1 W - B Ambient temperature sensor signal Ignition switch ON at 25°C (77°F) 1.35 to 1.75 V
    F1-39 (IG+) - Body ground P - Body ground Ignition power supply Ignition switch ON 11 to 14 V
    F1-40 (B) - Body ground L - Body ground Battery power supply Always 11 to 14 V

    • *1: w/ PTC Heater

    • If the result is not as specified, there may be a malfunction in the wire harness.