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


  1. CHECK AIR CONDITIONING AMPLIFIER ASSEMBLY

    A004OVBE02

    1. Disconnect the D47 air conditioning amplifier connector.

    2. Measure the voltage and resistance according to the value(s) in the table below.

      Terminal No. (Symbol) Wiring Color Terminal Description Condition Specified Condition
      D47-1 (IG+) - D47-14 (GND) Y - W-B Ignition power supply Ignition switch ON 11 to 14 V
      Ignition switch off Below 1 V
      D47-13 (SG-2) - Body ground V - Body ground Ground for air conditioning pressure sensor Always Below 1 Ω
      D47-14 (GND) - Body ground W-B - Body ground Ground for main power supply Always Below 1 Ω
      D47-21 (B) - D47-14 (GND) R - W-B Battery power source Always 11 to 14 V
      D47-34 (SG-1) - Body ground R - Body ground Ground for room temperature sensor Always Below 1 Ω

    3. Reconnect the D47 air conditioning amplifier connector.

    4. Measure the resistance, voltage and waveform according to the value(s) in the table below.

      Terminal No. (Symbol) Wiring Color Terminal Description Condition Specified Condition
      D47-2 (SOL+) - D47-14 (GND) LG - W-B Compressor with pulley assembly operation signal

      • Engine running

      • A/C switch on

      • Blower switch LO

      Pulse generation

      (see waveform 2)
      D47-3 (PTC2) - Body ground B - Body ground HTR SUB NO. 2 relay operation signal

      • Engine running (1250 rpm or more)

      • Temperature setting: MAX. HOT

      • Outside temperature: 10°C (50°F) or less

      • Engine coolant temperature: 70°C (158°F)

      • Headlight dimmer switch: off

      • Blower switch: off

      		 11 to 14 V*3

      • Engine running (1250 rpm or more)

      • Temperature setting: MAX. HOT

      • Outside temperature: 10°C (50°F) or less

      • Engine coolant temperature: 70°C (158°F)

      • Headlight dimmer switch: off

      • Blower switch: on

      		 Below 1 V*3
      D47-9 (PRE) - D47-13 (SG-2) G - V Air conditioning pressure sensor signal

      • Ignition switch ON

      • Refrigerant pressure: Normal pressure (less than 3.025 MPa [30.9 kgf/cm2, 438.6 psi] and more than 0.176 MPa [1.8 kgf/cm2, 25.5 psi])

      		 0.70 to 4.69 V

      • Ignition switch ON

      • Refrigerant pressure: Abnormal (less than 0.176 MPa [1.8 kgf/cm2, 25.5 psi])

      		 Below 0.70 V

      • Ignition switch ON

      • Refrigerant pressure: Abnormal (more than 3.025 MPa [30.9 kgf/cm2, 438.6 psi])

      		 4.69 V or higher
      D47-10 (S5-3) - D47-13 (SG-2) B - V Power supply for air conditioning pressure sensor Ignition switch ON 4.75 to 5.25 V
      D47-22 (BLW) - D47-14 (GND) G - W-B Blower motor control signal

      • Ignition switch ON

      • Blower switch LO

      Pulse generation

      (see waveform 1)
      D47-27 (HLS) - D47-14 (GND) B - W-B Headlight signal (PTC Heater control)

      • Engine started

      • Headlight dimmer switch: off

      		 11 to 14 V

      • Engine started

      • Headlight dimmer switch: on

      		 Below 1 V
      D47-29 (TR) - D47-34 (SG-1) GR - R Room temperature sensor signal

      • Ignition switch ON

      • Cabin temperature at 25°C (77°F)

      		 1.8 to 2.2 V

      • Ignition switch ON

      • Cabin temperature at 40°C (104°F)

      		 1.2 to 1.6 V
      D47-30 (S5-1) - D47-14 (GND) LG - W-B Cooler thermistor (solar sensor) power source Ignition switch ON 4.5 to 5.5 V
      D47-32 (TSP) - D47-14 (GND)

      L - W-B*1

      P - W-B*2

      		 Cooler thermistor (solar sensor) power signal (for front passenger side)

      • Ignition switch ON

      • Solar sensor subjected to electric light

      • Vehicle indoors

      		 0.8 to 4.3 V

      • Ignition switch ON

      • Solar sensor covered with cloth

      • Vehicle indoors

      		 Below 0.8 V
      D47-33 (TSD) - D47-14 (GND)

      P - W-B*1

      L - W-B*2

      		 Cooler thermistor (solar sensor) power signal (for driver side)

      • Ignition switch ON

      • Solar sensor subjected to electric light

      • Vehicle indoors

      		 0.8 to 4.3 V

      • Ignition switch ON

      • Solar sensor covered with cloth

      • Vehicle indoors

      		 Below 0.8 V
      D47-39 (PTC3) - Body ground BR - Body ground HTR SUB NO. 3 relay operation signal

      • Engine running (1250 rpm or more)

      • Temperature setting: MAX. HOT

      • Outside temperature: 10°C (50°F) or less

      • Engine coolant temperature: 65°C (149°F) or less

      • Headlight dimmer switch: off

      • Blower switch: off

      		 11 to 14 V*3

      • Engine running (1250 rpm or more)

      • Temperature setting: MAX. HOT

      • Outside temperature: 10°C (50°F) or less

      • Engine coolant temperature: 65°C (149°F) or less

      • Headlight dimmer switch: off

      • Blower switch: on

      		 Below 1 V*3
      D47-40 (PTC1) - Body ground W - Body ground HTR SUB NO. 1 relay operation signal

      • Engine running (1250 rpm or more)

      • Temperature setting: MAX. HOT

      • Outside temperature: 10°C (50°F) or less

      • Engine coolant temperature: 75°C (167°F) or less

      • Headlight dimmer switch: off

      • Blower switch: off

      		 11 to 14 V*3

      • Engine running (1250 rpm or more)

      • Temperature setting: MAX. HOT

      • Outside temperature: 10°C (50°F) or less

      • Engine coolant temperature: 75°C (167°F) or less

      • Headlight dimmer switch: off

      • Blower switch: on

      		 Below 1 V*3
      z3-2 (BUS G) - Body ground - Ground for BUS IC Always Below 1 Ω
      z3-3 (BUS) - z3-2 (BUS G) - BUS IC control signal Ignition switch ON Pulse generation
      z3-4 (B BUS) - z3-2 (BUS G) - Power supply for BUS IC Always 11 to 14 V
      z3-5 (SGA) - Body ground - Ground for evaporator temperature sensor Always Below 1 Ω
      z3-6 (TEA) - z3-5 (SGA) - Evaporator temperature sensor signal

      • Ignition switch ON

      • Evaporator temperature at 0°C (32°F)

      		 1.7 to 2.1 V

      • Ignition switch ON

      • Evaporator temperature at 15°C (59°F)

      		 0.9 to 1.3 V

      • *1: for LHD

      • *2: for RHD

      Tech Tips

      *3: After the measurement conditions are met, wait 30 seconds before performing measurements.

    5. A004R8IE68

      Using an oscilloscope, check waveform 1.

      Blower Motor Control Signal
      Item Content
      Terminal No. (Symbol) D47-22 (BLW) - D47-14 (GND)
      Tool Setting 1 V/DIV., 500 μs/DIV.
      Condition

      Ignition switch ON

      Blower switch LO

      Tech Tips

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

    6. A004SF2E36

      Using an oscilloscope, check waveform 2.

      Compressor and Pulley Operation Signal
      Item Content
      Terminal No. (Symbol) D47-2 (SOL+) - D47-14 (GND)
      Tool Setting 5 V/DIV., 500 μs/DIV.
      Condition

      Engine running

      A/C switch on

      Blower switch LO

  2. CHECK AIR CONDITIONING CONTROL ASSEMBLY

    A004ONUE03

    1. Disconnect the D12 control connector.

    2. Measure the resistance and voltage according to the value(s) in the table below.

      Terminal No. (Symbol) Wiring Color Terminal Description Condition Specified Condition
      D12-5 (IG+) - D12-11 (GND) G - BR IG power supply Ignition switch ON 10.5 to 16 V
      Ignition switch off Below 1 V
      D12-11 (GND) - Body ground BR - Body ground Ground Always Below 1 Ω

  3. CHECK MAIN BODY ECU (INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY)

    A004TMTE04

    1. Disconnect the DH, DE, DG and D80 ECU connectors.

    2. Measure the voltage and resistance according to the value(s) in the table below.

      Terminal No. (Symbol) Wiring Color Terminal Description Condition Specified Condition
      D80-4 (GND2) - Body ground W-B - Body ground Ground Always Below 1 Ω
      DH-12 (BECU) - Body ground W - Body ground Power source Always 11 to 14 V
      DE-17 (GND1) - Body ground W-B - Body ground Ground Always Below 1 Ω
      DG-1 (ALTB) - Body ground W - Body ground Power source Always 11 to 14 V