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


  1. CHECK AIR CONDITIONING AMPLIFIER ASSEMBLY

    A003E3OE08

    1. Disconnect the D101 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
      D101-1 (IG+) - D101-14 (GND) Y - W-B Ignition power supply Ignition switch ON 11 to 14 V
      Ignition switch off Below 1 V
      D101-21 (B) - D101-14 (GND) R - W-B Battery power source Always 11 to 14 V
      D101-14 (GND) - Body ground W-B - Body ground Ground for main power supply Always Below 1 Ω
      D101-13 (SG-2) - Body ground V - Body ground Ground for air conditioning pressure sensor Always Below 1 Ω

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

    3. Reconnect the D101 air conditioning amplifier connector.

    4. Measure the voltage according to the value(s) in the table below.

      Terminal No. (Symbol) Wiring Color Terminal Description Condition Specified Condition
      z3-2 (BUS G) - Body ground - Ground for BUS IC Always Below 1 Ω
      D101-23 (BLW) - D101-14 (GND) G - W-B Blower motor control signal

      • Ignition switch ON

      • Blower switch LO

      Pulse generation

      (see waveform 1)
      D101-10 (S5-3) - D101-13 (SG-2) B - V Power supply for air conditioning pressure sensor Ignition switch ON 4.75 to 5.25 V
      D101-9 (PRE) - D101-13 (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
      D101-2 (SOL+) - D101-14 (GND) LG - W-B Compressor with pulley assembly operation signal

      • Engine running

      • A/C switch on

      • Blower switch LO

      Pulse generation

      (see waveform 2)
      D101-3 (PTC1) - Body ground W - Body ground PTC 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: on

      		 11 to 14 V*
      D101-22 (PTC2) - Body ground B - Body ground PTC 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: on

      		 11 to 14 V*
      D101-4 (PTC3) - Body ground BR - Body ground PTC 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: on

      		 11 to 14 V*
      D101-25 (ALT) - D101-14 (GND) L - W-B Generator signal (PTC Heater control) Engine started Pulse generation
      D101-27 (HLS) - D101-14 (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
      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
      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

      *: After the measurement conditions are met, wait 30 seconds before performing measurements. If the result is not as specified, the air conditioning amplifier assembly may have a malfunction.


      • If the result is not as specified, the air conditioning amplifier assembly may have a malfunction.

    5. A003BB7E12

      Using an oscilloscope, check waveform 1.

      Blower Motor Control Signal
      Item Content
      Terminal No. (Symbol) D101-23 (BLW) - D101-14 (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. A003BG9E10

      Using an oscilloscope, check waveform 2.

      Compressor and Pulley Operation Signal
      Item Content
      Terminal No. (Symbol) D101-2 (SOL+) - D101-14 (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

    A003B2DE16

    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) P - BR IG power supply Ignition switch ON 11 to 14 V
      D12-11 (GND) - Body ground BR - Body ground Ground Always Below 1 Ω

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

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

    A003D2DE01

    1. Disconnect the DB, 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
      DE-17 (GND1) - Body ground W-B - Body ground Ground Always Below 1 Ω
      D80-4 (GND2) - Body ground W-B - Body ground Ground Always Below 1 Ω
      DB-30 (BECU) - Body ground W - Body ground Power souse Always 11 to 14 V
      DG-1 (ALTB) - Body ground W - Body ground Power souse Always 11 to 14 V

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