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Terminals Of Ecu

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  1. INSPECT AIR CONDITIONER AMPLIFIER ASSEMBLY 
    1. Disconnect the connector from the air conditioner amplifier assembly and inspect the connector on the wire harness side, as shown in ECU CONNECTOR REFERENCE TABLE .
      Fig 1: Identifying A14 Connector Terminal - Wire Harness Side
      G04411355Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      ECU CONNECTOR REFERENCE TABLE

      Symbols (Terminals No.) Wiring Colors Terminal Descriptions Conditions STD Voltages
      IG+ (A14-12) - GND (A14-1) P - W-B Power source (IG) Ignition switch: OFF --> ON Below 1.0 --> 10 to 14 V
      +B (A14-24) - GND (A14-1) P - W-B Power source (Back-up) Always 10 to 14 V
      GND (A14-1) - Body ground W-B - Body ground Ground for main power supply Always Below 1.0

      If the results are not as specified, inspect the circuits connected to the other parts.

    2. Connect the connector to the air conditioning amplifier assembly and inspect the wire harness side connector from the back side, as shown in Fig 2.
      Fig 2: Identifying A14 Connector Terminal - From Back Side
      G04411356Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      ECU CONNECTOR REFERENCE TABLE

      Symbols (Terminals No.) Wiring Colors Terminal Descriptions Conditions STD Voltages
      DEF (A14-2) - GND (A14-1) LG - W-B Mode switch signal Ignition switch: ON
      Mode select switch:
      Except DEF --> DEF      		 1.0 to 14 --> Below 1.0 V
      LOCK (A14-6) - SG (A14-3) R-W - W Magnet clutch signal Start engine
      Operate A/C system
      Magnet clutch: ON      		 Pulse generation (See WAVEFORM 1 )
      ACI (A14-9) - GND (A14-1) G-W - W-B Idle up request signal Engine idling
      Operate A/C system
      Magnet clutch: OFF --> ON      		 10 to 14 --> Below 1.0 V
      FRS (A14-10) - GND (A14-1) V-W - W-B Recirculation/Fresh switch signal Ignition switch: ON
      Recirculation/Fresh switch:
      RECIRCULATION --> FRESH      		 Below 1.0 --> 10 to 14 V
      REC (A14-11) - GND (A14-1) P-B - W-B Recirculation/Fresh switch signal Ignition switch: ON
      Recirculation/Fresh switch:
      FRESH --> RECIRCULATION      		 Below 1.0 --> 10 to 14 V
      MGC (A14-21) - GND (A14-1) G - W-B Magnet clutch relay signal Engine idling
      Operate A/C system
      Magnet clutch: OFF --> ON      		 10 to 14 --> Below 1.0 V
      PRS (A14-5) - GND (A14-1) O - W-B A/C pressure sensor signal Start engine
      Operate A/C system
      Refrigerant pressure: Abnormal (More than 3,030 kPa (31.0 kgf/cm2 , 440 psi))      		 4.7 V or higher
      PRS (A14-5) - GND (A14-1) O - W-B A/C pressure sensor signal Start engine
      Operate A/C system
      Refrigerant pressure: Abnormal (Less than 186 kPa (1.9 kgf/cm2 , 27 psi))      		 Below 0.7 V
      PRS (A14-5) - GND (A14-11) O - W-B A/C pressure sensor signal Start engine
      Operate A/C system
      Refrigerant pressure: Normal (Less than 3,030 kPa (31.0 kgf/cm2 , 440 psi)) and more than 186 kPa (1.9 kgf/cm2 , 27 psi))      		 0.7 to 4.7 V
      TE (A14-4) - GND (A14-1) B - W-B A/C evaporator temperature sensor signal Ignition switch: ON
      Evaporator temperature: 0 --> 15°C (32 --> 59°F)      		 2.0 to 2.4 --> 1.4 to 1.8 V
      BLRH (A14-23) - GND (A14-1) G-Y - W-B Blower switch signal Ignition switch: ON
      Blower switch: ON
      OFF --> ON (LO, M1, M2, H1)      		 0 --> 10 to 14 V
      ACID (A14-15) - GND (A14-1) Y - W-B A/C switch LED signal Ignition switch: ON
      Blower switch: ON
      A/C switch: OFF --> ON      		 10 to 14 --> Below 3.0 V
      RDEF (A14-16) - GND (A14-1) L-W - W-B REC switch LED signal Ignition switch: ON
      Blower switch: ON
      REC switch: OFF --> ON      		 10 to 14 --> Below 1.0 V
      MR/F (A14-17) - GND (A14-1) G-B - W-B REC switch operation signal Ignition switch: ON
      REC switch: OFF --> ON      		 4 to 5 --> Below 1.0 V
      A/C (A14-18) - GND (A14-1) GR - W-B A/C switch operation signal Ignition switch: ON
      A/C switch: OFF --> ON      		 4 to 5 --> Below 1.0 V
      GND (A14-1) - Body ground W-B - Body ground Ground for main power supply Always Below 1.0
      SG (A14-3) - Body ground W - Body ground Ground for A/C evaporator temperature sensor Always Below 1.0
      IG (A14-12) - Body ground P - Body ground Power source (IG) Ignition switch: OFF --> ON Below 1.0 --> 10 to 14 V
      +B (A14-24) - Body ground R - Body ground Power source (Back-up) Always 10 to 14 V

      If the results are not as specified, replace the air conditioning amplifier assembly with a new one. If the results are still not as specified after replacing the air conditioning control assembly, inspect the circuits connected to other parts.

      1. WAVEFORM 1:

        Magnet clutch signal

        WAVEFORM REFERENCE TABLE

        ECM Terminal Names Between LOCK and SG
        Tester Ranges 0.2 V/DIV, 10 msec./DIV
        Conditions Idling

        HINT:

        The wavelength becomes shorter as the engine rpm increases.

        Fig 3: Identifying Waveform 1
        G04411357Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  2. Inspect ECM (2TR-FE) 
    1. Connect the connector to the ECM and inspect the wire harness side connector from the back side, as shown in Fig 4.
      Fig 4: Identifying ECM Connector Terminal
      G04411358Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      ECM CONNECTOR REFERENCE TABLE

      Symbols (Terminals No.) Wiring Colors Terminal Descriptions Conditions STD Voltages
      ACT (E7-25) - E1 (E4-3) L - BR Magnet clutch ON Permit signal Start engine
      Operate A/C system
      Accelerator pedal:
      released --> depressed      		 10 to 14 --> Below 1.0 V
      THWO (E7-14) - E2 (E4-28) GR-B - BR Engine coolant temperature sensor signal Ignition switch: ON Pulse generation (See WAVEFORM 1 )
      TACH (E7-1) - E1 (E4-3) B-W - BR Engine speed signal Engine idling Pulse generation (See WAVEFORM 2 )
      1. WAVEFORM 1:

        Engine coolant temperature sensor signal

        WAVEFORM REFERENCE TABLE

        ECM Terminal Names Between THWO and E2
        Tester Ranges 5 V/DIV, 0.1 sec./DIV
        Conditions Ignition switch ON

        A changes in accordance with the engine coolant temperature.

        COOLANT TEMPERATURE SPECIFICATION

        Coolant Temperature Below 30° Approx. 75°C Above 90°F
        A Approx. 16 ms Approx. 204 ms Approx. 262 ms
        Fig 5: Identifying Waveform 1
        G04411359Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      2. WAVEFORM 2:

        Engine speed signal

        WAVEFORM REFERENCE TABLE

        ECM Terminal Names Between TACH and E1
        Tester Ranges 5 V/DIV, 10 msec./DIV
        Conditions Idling

        HINT:

        The wavelength becomes shorter as the engine rpm increases.

        Fig 6: Identifying Waveform 2
        G04411360Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  3. INSPECT ECM (1GR-FE) 
    1. Connect the connector to the ECM and inspect the wire harness side connector from the back side, as shown in ECM CONNECTOR REFERENCE TABLE .
      Fig 7: Identifying ECM Connector Terminal
      G04411361Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      ECM CONNECTOR REFERENCE TABLE

      Symbols (Terminals No.) Wiring Colors Terminal Descriptions Conditions STD Voltages
      ACT (E7-25) - E1 (E6-1) L - BR Magnet clutch ON permit signal Start engine
      Operate A/C system
      Accelerator pedal: released --> depressed      		 10 to 14 --> Below 1.0 V
      THWO (E7-14) - E2 (E4-28) GR-B - BR Engine coolant temperature sensor signal Ignition switch: ON Pulse generation (See WAVEFORM 1 )
      TACH (E7-1) - E1 (E6-1) B-W - BR Engine speed signal Engine idling Pulse generation (See WAVEFORM 2 )
      1. WAVEFORM 1:
        WAVEFORM REFERENCE TABLE

        ECM Terminal Names Between THWO and E2
        Tester Ranges 5 V/DIV, 0.1 sec./DIV
        Conditions Ignition switch ON

        Engine coolant temperature sensor signal A changes in accordance with the engine coolant temperature.

        COOLANT TEMPERATURE SPECIFICATION

        Coolant Temperature Below 30° Approx. 75° Above 90°
        A Approx. 16 ms Approx. 204 ms Approx. 262 ms
        Fig 8: Identifying Waveform 1
        G04411362Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      2. WAVEFORM 2:

        Engine speed signal

        WAVEFORM REFERENCE TABLE

        ECM Terminal Names Between TACH and E1
        Tester Ranges 5 V/DIV, 10 msec./DIV
        Conditions Idling

        HINT:

        The wavelength becomes shorter as the engine rpm increases.

        Fig 9: Identifying Waveform 2
        G04411363Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
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