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


  1. CHECK AIR CONDITIONING AMPLIFIER

    A01184DE01

    Tech Tips

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

    Standard
    Terminal No. (Symbol) Wiring Color Terminal Description Condition Specified Condition
    D16-4 (FLOQ) - D16-10 (SG-2) SB - GR Flow sensor signal

    Engine idling

    A/C switch off

    		 3.76 to 4.7 V

    Engine idling

    A/C switch on

    		 0.3 to 3.76 V
    D16-7 (S5-3) - D16-24 (GND) L - W-B Power supply for pressure sensor and flow sensor Ignition switch: ON 4.75 to 5.25 V
    D16-8 (TX+) - D16-24 (GND) LG - W-B Hi-level CAN bus line Ignition switch: ON

    Pulse generation

    (see waveform 1)
    D16-9 (TX-) - D16-24 (GND) W - W-B Low-level CAN bus line Ignition switch: ON

    Pulse generation

    (see waveform 2)
    D16-10 (SG-2) - Body ground GR - Body ground Ground for pressure sensor and flow sensor Always Below 1.0 Ω
    D16-12 (PRE) - D16-23 (SG-1) P - V Air conditioner pressure sensor signal Refrigerant pressure: normal 0.70 to 4.69 V
    D16-12 (PRE) - D16-23 (SG-1) P - V Air conditioner pressure sensor signal

    Refrigerant pressure: abnormal

    (less than 0.176 MPa [1.8 kgf/cm2] or more than 3.025 MPa [30.9 kgf/cm2])

    		 Below 0.70 V or 4.69 V or more
    D16-13 (SOL+) - D16-24 (GND) R - W-B A/C compressor operation signal

    Engine idling

    Blower switch: 1

    A/C switch: on

    Pulse generation

    (see waveform 3)
    D16-14 (IG+) - D16-24 (GND) Y - W-B Ignition power supply Ignition switch: ON 11 to 14 V
    Ignition switch: off Below 1 V
    D16-15 (MGC) - D16-24 (GND) B - W-B A/C compressor magnetic clutch operation signal

    Engine idling

    A/C switch: on

    Blower switch: 0 → 1

    		 Below 1 V → 11 to 14 V

    Engine idling

    A/C switch: off

    Blower switch: 0 → 1

    		 Below 1 V → Below 1 V
    D16-21 (SBLW) - D16-24 (GND) G - W-B Blower motor control signal

    Ignition switch: ON

    Blower switch: 0 → 1

    		 11 to 14 V → Below 1 V
    D16-22 (TE) - D16-10 (SG-2) Y - GR Front evaporator temperature sensor signal

    Ignition switch: ON

    Evaporator temperature: 0°C (32°F)

    		 2.0 to 2.4 V

    Ignition switch: ON

    Evaporator temperature: 15°C (59°F)

    		 1.4 to 1.8 V
    D16-23 (SG-1) - Body ground V - Body ground Ground for front evaporator temperature sensor Always Below 1.0 Ω
    D16-24 (GND) - Body ground W-B - Body ground Ground for main power supply Always Below 1.0 Ω
    D16-27 (A/C) - D16-24 (GND) SB - W-B A/C switch signal

    Ignition switch: ON

    Defroster: off

    A/C switch: off→ on

    		 Below 1 V → 11 to 14 V
    Defroster mode detection switch signal

    Ignition switch: ON

    A/C switch: off

    Defroster: off→ on

    		 Below 1 V → 11 to 14 V
    D16-28 (LED) - Body ground L - Body ground A/C switch indicator signal

    Engine idling

    A/C switch: on

    Blower switch: 0 → 1

    		 11 to 14 V → Below 4 V
    D17-9 (PTC1)* - D16-24 (GND) G - W-B PTC heater relay operation signal

    Engine idling

    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: 10 seconds

    		 Below 1 V → 11 to 14 V
    D17-10 (PTC2)* - D16-24 (GND) W - W-B PTC heater relay operation signal

    Engine idling

    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: 20 seconds

    		 Below 1 V → 11 to 14 V
    D17-12 (PTC3)* - D16-24 (GND) L - W-B PTC heater relay operation signal

    Engine idling

    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

    		 Below 1 V → 11 to 14 V
    D17-14 (HEAT)* - Body ground P - Body ground MAX HOT switch detection signal

    Ignition switch: ON

    No. 3 heater control knob: Max Hot

    		 11 to 14 V
    D17-23 (HLS)* - Body ground B - Body ground Headlight signal

    Engine idling

    Head light switch: on

    		 11 to 14 V → Below 1 V
    D17-24 (ALT)* - D16-24 (GND) LG - W-B Generator signal Engine idling Pulse generation

    • *: w/ PTC Heater

    • If the result is not as specified, the ECU may have a malfunction.


    1. A0119N6E42

      Waveform 1 : Using an oscilloscope

      CAN Communication Signal
      Terminal Name Between D16-8 (TX+) - D16-24 (GND)
      Tester Range 1 V/DIV., 10 μs./DIV.
      Condition Ignition switch ON

      Tech Tips

      The waveform varies depending on the CAN communication signal.

    2. A01177ZE39

      Waveform 2 : Using an oscilloscope

      CAN Communication Signal
      Terminal Name Between D16-9 (TX-) - D16-24 (GND)
      Tester Range 1 V/DIV., 10 μs./DIV.
      Condition Ignition switch ON

      Tech Tips

      The waveform varies depending on the CAN communication signal.

    3. A011B68E16

      Waveform 3 : Using an oscilloscope

      Air Conditioning Compressor Operation Signal
      Terminal Name Between D16-13 (SOL+) - D16-24 (GND)
      Tester Range 5 V/DIV., 500 μs./DIV.
      Condition Engine idling, Blower switch 1, A/C switch on

  2. CHECK COMBINATION METER ASSEMBLY

    A0119T8E01

    Tech Tips

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

    Standard
    Terminal No. (Symbol) Wiring Color Terminal Description Condition Specified Condition
    D1-4 (TX1-) - Body ground V - Body ground Ambient temperature sensor signal

    Ignition switch: ON

    Ambient temperature: 25°C (77°F)

    		 1.5 V
    D1-23 (TX1+) - Body ground L - Body ground Ambient temperature sensor ground Always Below 1.0 Ω

    If the result is not as specified, the combination meter may have a malfunction.