AIR CONDITIONING SYSTEM TERMINALS OF ECU


  1. CHECK AIR CONDITIONING AMPLIFIER ASSEMBLY

    A004GH5E03

    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
    F29-1 (IG+) - F29-14 (GND) V - BR Power source (IG) Ignition switch ON (IG) 11 to 14 V
    F29-3 (PTC3) - F29-14 (GND)*1 V - BR Quick heater operation signal Ignition switch ON (READY) Below 1 V
    ECO switch assembly (ECO mode switch) off
    Blower motor on
    Temperature settings: MAX HOT
    Engine coolant temperature approximately 50°C lower
    Ambient temperature 10°C or lower
    IDH terminal signal less than 1 V (Inverter with converter assembly overload not detected)
    F29-4 (ECOS) - F29-14 (GND) R - BR ECO switch assembly (ECO mode switch) signal Ignition switch ON (IG) Below 1 V
    ECO switch assembly (ECO mode switch) on
    Ignition switch ON (IG) 11 to 14 V
    ECO switch assembly (ECO mode switch) off
    F29-5 (TAM) - F29-13 (SG-2) W - L A/C ambient temperature sensor signal Ignition switch ON (IG) at 25°C (77°F) 1.35 to 1.75 V
    F29-9 (PRE) - F29-14 (GND) GR - BR Air conditioning pressure sensor signal Ignition switch ON (READY) 0.63 to 4.73 V
    A/C system operating
    Refrigerant pressure: Normal
    Ignition switch ON (READY) Below 0.63 V or 4.73 V or more
    A/C system operating

    Refrigerant pressure: Abnormal (less than 0.176 MPaG [1.8 kgf/cm2]) or more than 3.03 MPaG [31 kgf/cm2])
    F29-10 (S5-3) - F29-14 (GND) Y - BR Power supply for pressure sensor Ignition switch ON (IG) 4.75 to 5.25 V
    F29-11 (CANH) - F29-14 (GND) V - BR CAN communication signal Ignition switch ON (IG)

    Pulse generation

    (See waveform 1)
    F29-12 (CANL) - F29-14 (GND) W - BR CAN communication signal Ignition switch ON (IG)

    Pulse generation

    (See waveform 2)
    F29-13 (SG-2) - Body ground L - Body ground Ground for ambient temperature sensor and A/C pressure sensor Always Below 1 Ω
    F29-14 (GND) - Body ground BR - Body ground Ground for main power supply Always Below 1 Ω
    F29-21 (B) - F29-14 (GND) BE - BR Power source (Back-up) Always 11 to 14 V
    F29-22 (BLW) - F29-14 (GND) R - BR Blower motor control signal Ignition switch ON (IG)

    Pulse generation

    (See waveform 3)
    Blower switch: LO
    F29-27 (IDH) - F29-14 (GND)*1 L - BR Inverter with converter assembly current over signal Ignition switch ON (IG) (inverter with converter assembly overload not detected) Less than 1 V
    F29-29 (TR) - F29-34 (SG-1) P - SB Room temperature sensor signal Ignition switch ON (IG) 1.8 to 2.2 V
    Vehicle interior temperature: 25°C
    F29-30 (S5-4) - F29-14 (GND)*2 L - BR Solar sensor power supply Ignition switch ON (IG) 4.5 to 5.5 V
    F29-33 (TSD) - F29-14 (GND) R - BR Solar sensor signal Ignition switch ON (IG) 0.8 to 4.3 V
    Solar sensor subject to electric light
    F29-34 (SG-1) - Body ground SB - Body ground Ground for room temperature sensor Always Below 1 Ω
    F29-37 (LIN1) - F29-14 (GND) LG - BR LIN communication signal Ignition switch ON (IG) Pulse generation
    F29-39 (PTC2) - F29-14 (GND)*1 BR - BR Quick heater operation signal Ignition switch ON (READY) Below 1 V
    ECO switch assembly (ECO mode switch) off
    Blower motor on
    Temperature settings: MAX HOT
    Engine coolant temperature approximately 50°C lower
    Ambient temperature 10°C or lower
    IDH terminal signal less than 1 V (Inverter with converter assembly overload not detected)
    F29-40 (PTC1) - F29-14 (GND)*1 SB - BR Quick heater operation signal Ignition switch ON (READY) Below 1 V
    ECO switch assembly (ECO mode switch) off
    Blower motor on
    Temperature settings: MAX HOT
    Engine coolant temperature approximately 50°C or lower
    Ambient temperature 10°C or lower
    IDH terminal signal less than 1 V (Inverter with converter assembly overload not detected)
    z1-2 (BUS G) - Body ground - Ground for BUS IC Always Below 1 Ω
    z1-3 (BUS) - z1-2 (BUS G) - BUS IC control signal Ignition switch ON (IG) Pulse generation
    z1-4 (B BUS) - z1-2 (BUS G) - BUS IC power supply Always 11 to 14 V
    z1-5 (SGA) - Body ground - Ground for evaporator temperature sensor Always Below 1 Ω
    z1-6 (TEA) - z1-5 (SGA) - Evaporator temperature sensor signal Ignition switch ON (IG) 1.4 to 1.8 V
    Evaporator temperature: 15°C (59°F)

    • *1: w/ PTC Heater

    • *2: w/o Automatic Light Control System

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


    1. A004FYHE01
      *a 1 V/DIV.
      *b 10 μsec./DIV.

      Waveform 1 (Reference) : Using an oscilloscope

      CAN Communication Signal
      Terminal Name F29-11 (CANH) - F29-14 (GND)
      Tester Range 1 V/DIV, 10 μsec./DIV.
      Condition Ignition switch ON (IG)

      Tech Tips

      The waveform varies depending on the CAN communication signal.

    2. A004FZ7E95
      *a 1 V/DIV.
      *b 10 μsec./DIV.

      Waveform 2 (Reference) : Using an oscilloscope

      CAN Communication Signal
      Terminal Name F29-12 (CANL) - F29-14 (GND)
      Tester Range 1 V/DIV, 10 μsec./DIV.
      Condition Ignition switch ON (IG)

      Tech Tips

      The waveform varies depending on the CAN communication signal.

    3. A004FSNE50
      *a 1 V/DIV.
      *b 500 μsec/DIV.

      Waveform 3: Using an oscilloscope.

      Blower Motor Control Signal
      Terminal Name F29-22 (BLW) - F29-14 (GND)
      Tester Range 1 V/DIV, 500 μsec./DIV.
      Condition

      Ignition switch ON (IG)

      Blower switch LO

      Tech Tips

      When the blower level is increased, the duty ratio changes accordingly.

  2. CHECK AIR CONDITIONING CONTROL ASSEMBLY

    A004GDIE03
    Terminal No. (Symbol) Wiring Color Terminal Description Condition Specified Condition
    F28-5 (IG+) - F28-8 (GND) V - BR Power source (IG) Ignition switch ON (IG) 11 to 14 V
    F28-3 (LIN1) - F28-8 (GND) LG - BR LIN communication signal Ignition switch ON (IG) Pulse generation
    F28-8 (GND) - Body ground BR - Body Ground Ground for air conditioning control assembly Always Below 1 Ω

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

  3. HYBRID VEHICLE CONTROL ECU Click here

  4. INVERTER WITH CONVERTER ASSEMBLY Click here