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


  1. CHECK AIR CONDITIONING AMPLIFIER ASSEMBLY (w/ Rear Heater)

    B001X8NE02

    1. Disconnect the E36 and E35 air conditioning amplifier assembly 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
      E36-6 (+B1) - E36-1 (GND) R - W-B Battery power supply Always 11 to 14 V
      E36-7 (+B2) - E36-1 (GND) R - W-B Battery power supply Always 11 to 14 V
      E36-5 (IG+) - E36-1 (GND) G - W-B Ignition power supply Engine switch on (IG) 11 to 14 V
      Engine switch off Below 1 V
      E36-2 (E1) - Body ground W-B - Body ground Ground Always Below 1 Ω
      E36-1 (GND) - Body ground W-B - Body ground Ground Always Below 1 Ω
      E35-6 (E2) - Body ground W-B - 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. Reconnect the E36 and E35 air conditioning amplifier assembly connectors.

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

      Terminal No. (Symbol) Wiring Color Terminal Description Condition Specified Condition
      z53-3 (B BUS) - z53-1 (BUS G) - Power supply for BUS IC (for front) Always 11 to 14 V
      z53-10 (B BUS) - z53-8 (BUS G) - Power supply for BUS IC (for front) Always 11 to 14 V
      E36-14 (RBBU) - E36-12 (RBUG) L - BR Power supply for BUS IC (for rear) Always 11 to 14 V
      E35-25 (TR3) - Body ground V - Body ground Power supply for driver side duct sensor

      Engine switch on (IG)

      Driver side duct sensor temperature: 25°C (77°F)

      		 4.8 to 5.2 kΩ
      E35-26 (TR4) - Body ground W - Body ground Power supply for front passenger side duct sensor

      Engine switch on (IG)

      Front passenger side duct sensor temperature: 25°C (77°F)

      		 4.8 to 5.2 kΩ
      E35-16 (SG-2) - Body ground G - Body ground Ground for pressure sensor Always Below 1 Ω
      E35-29 (SG-5) - Body ground G - Body ground Ground for compressor signal Always Below 1 Ω
      E35-32 (SG-1) - Body ground B - Body ground Ground for room temperature sensor (for front) Always Below 1 Ω
      z53-6 (SGA) - Body ground - Ground for evaporator temperature sensor Always Below 1 Ω
      z53-1 (BUS G) - Body ground - Ground for BUS IC (for front) Always Below 1 Ω
      z53-8 (BUS G) - Body ground - Ground for BUS IC (for front) Always Below 1 Ω
      E35-34 (SGND) - Body ground BR - Body ground Ground for driver side duct sensor Always Below 1 Ω
      E35-12 (SG-9) - Body ground L - Body ground Ground for front passenger side duct sensor Always Below 1 Ω
      E35-2 (SG-6) - Body ground G - Body ground Ground for room temperature sensor signal (for Rear LH and Rear RH) Always Below 1 Ω
      E36-12 (RBUG) - Body ground BR - Body ground Ground for BUS IC (for rear) Always Below 1 Ω
      E35-1 (SG) - Body ground P - Body ground Ground for evaporator temperature sensor signal (for Rear) Always Below 1 Ω
      E36-25 (CFN+) - Body ground*1 R - Body ground Condenser fan operation signal Engine switch on (IG) 11 to 14 V
      E36-33 (COOL) - Body ground W - Body ground Cool box operation signal

      Engine switch on (IG)

      Cool box switch: On

      		 11 to 14 V
      E36-29 (AC1) - Body ground L - Body ground Compressor operation signal

      Engine switch on (IG)

      Blower switch: Lo

      A/C switch: Off

      		 11 to 14 V

      Engine switch on (IG)

      Blower switch: Lo

      A/C switch: On

      		 Below 1 V
      E36-22 (ACT) - Body ground G - Body ground Compressor operation signal

      Engine switch on (IG)

      Blower switch: Lo

      A/C switch: Off or on (magnet clutch off)

      		 Below 1 V

      Engine switch on (IG)

      Blower switch: Lo

      A/C switch: On (magnet clutch on)

      		 11 to 14 V
      E35-28 (LOCK) - E35-29 (SG-5) L - G Air compressor lock sensor signal

      Engine idling

      A/C switch: On (magnet clutch on)

      Blower switch: Lo

      Pulse generation

      (see waveform 1)
      E35-10 (TAM) - E35-16 (SG-2) V - G Ambient temperature sensor signal

      Engine switch on (IG)

      Ambient temperature:

      25°C (77°F)

      		 1.6 to 1.8 V

      Engine switch on (IG)

      Ambient temperature:

      50°C (122°F)

      		 0.5 to 0.7 V
      E35-27 (S5-1) - E35-16 (SG-2) LG - G Power supply for pressure sensor Engine switch on (IG) 4.5 to 5.5 V
      E35-20 (PRE) - E35-16 (SG-2) R - G Air conditioning pressure sensor signal

      Refrigerant pressure:

      Normal

      		 1.0 to 4.8 V

      Refrigerant pressure:

      Abnormal (less than 0.392 MPa [4.0 kgf/cm2, 57 psi])

      		 Below 1 V

      Refrigerant pressure:

      Abnormal (less than 3.187 MPa [32.5 kgf/cm2, 463 psi])

      		 4.8 V or higher
      E36-18 (MGC) - E36-1 (GND) R - W-B Compressor magnet clutch operation signal

      Engine idling

      Blower switch: Lo

      A/C switch: On (magnet clutch on permitted)

      		 Below 1 V
      E36-3 (BLW) - E36-1 (GND) R - W-B Blower motor control signal

      Engine switch on (IG)

      Blower switch: Lo

      Pulse generation

      (see waveform 2)
      E35-9 (TR) - E35-32 (SG-1) W - B Room temperature sensor signal (for front)

      Engine switch on (IG)

      Front side interior temperature: 25°C (77°F)

      		 1.6 to 1.8 V
      Room temperature sensor signal (for front)

      Engine switch on (IG)

      Front side interior temperature: 50°C (122°F)

      		 0.5 to 0.7 V
      E35-7 (TSD) - Body ground LG - Body ground Driver side solar sensor signal

      Engine switch on (IG)

      Solar sensor subjected to electric light

      		 0.8 to 4.3 V
      E35-8 (TSP) - Body ground GR - Body ground Passenger side solar sensor signal

      Engine switch on (IG)

      Solar sensor subjected to electric light

      		 0.8 to 4.3 V
      z53-7 (TEA) - z53-6 (SGA) - Evaporator temperature sensor signal

      Engine switch on (IG)

      Evaporator temperature: 15°C (59°F)

      		 1.4 to 1.8 V
      z53-2 (BUS) - z53-1 (BUS G) - BUS IC control signal (for front) Engine switch on (IG) Pulse generation
      z53-9 (BUS) - z53-8 (BUS G) - BUS IC control signal (for front) Engine switch on (IG) Pulse generation
      E35-18 (TR) - E35-2 (SG-6) R - G Room temperature sensor signal (for Rear LH)

      Engine switch on (IG)

      Vehicle interior temperature: 25°C (77°F)

      		 1.6 to 1.8 V

      Engine switch on (IG)

      Vehicle interior temperature: 50°C (122°F)

      		 0.5 to 0.7 V
      E35-19 (TR7) - E35-2 (SG-6) R - G Room temperature sensor signal (for Rear RH)

      Engine switch on (IG)

      Vehicle interior temperature: 25°C (77°F)

      		 1.6 to 1.8 V

      Engine switch on (IG)

      Vehicle interior temperature: 50°C (122°F)

      		 0.5 to 0.7 V
      E36-13 (RBUS) - E36-12 (RBUG) R - BR BUS IC control signal (for rear) Engine switch on (IG) Pulse generation
      E35-17 (TEC) - E35-1 (SG) W - P Evaporator temperature sensor signal (for Rear)

      Engine switch on (IG)

      Evaporator temperature:

      15°C (59°F)

      		 1.4 to 1.8 V
      E36-31 (ALT) - Body ground R - Body ground Generator signal Engine idling Pulse generation
      E36-32 (SW1) - Body ground BR - Body ground Idle up operation signal

      Engine switch on (IG)

      Idle up switch: Off

      		 Below 1 V

      Engine switch on (IG)

      Idle up switch: On

      		 11 to 14 V
      E36-20 (LIN1) - E36-1 (GND) Y - W-B

      LIN communication signal

      (for A/C switch)

      		 Engine switch on (IG) Pulse generation
      E36-21 (RLIN) - E36-1 (GND) L - W-B

      LIN communication signal

      (for Rear A/C switch)

      		 Engine switch on (IG) Pulse generation
      E36-27 (PTC1) - Body ground*2 W - Body ground PTC1 heater relay operation signal

      Engine idling

      Set temperature: MAX HOT

      Engine coolant temperature: Below 65°C (149°F)

      Ambient temperature: Below 10°C (50°F)

      Blower switch: Off → Lo

      		 Below 1 V → 11 to 14 V
      E36-26 (PTC2) - Body ground*2 R - Body ground PTC2 heater relay operation signal
      E36-35 (PTC3) - Body ground*2 R - Body ground PTC3 heater relay operation signal
      E36-17 (BLWH) - E36-1 (GND) L - W-B Blower motor control signal (for rear)

      Engine switch on (IG)

      Blower switch: Lo

      Pulse generation

      (see waveform 3)
      E36-19 (RMGV) - E36-1 (GND) B - W-B Rear cooling unit expansion valve signal Engine switch on (IG) 11 to 14 V

      • *1: w/ Condenser Fan

      • *2: w/ PTC Heater

    5. B001WNQE05

      Using an oscilloscope, check waveform 1.

      Compressor Lock Sensor Signal
      Item Content
      Terminal No. (Symbol) E35-28 (LOCK) - E35-29 (SG-5)
      Tool Setting 200 mV/DIV., 10 ms/DIV.
      Condition

      Engine idling

      Blower switch: Lo

      A/C switch: On

      Tech Tips

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

    6. B001YRCE55

      Using an oscilloscope, check waveform 2.

      Blower Motor Control Signal
      Item Content
      Terminal No. (Symbol) E36-3 (BLW) - E36-1 (GND)
      Tool Setting 1 V/DIV., 500 μs/DIV.
      Condition

      Engine switch on (IG)

      Blower switch: Lo

      Tech Tips

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

    7. B001YRCE55

      Using an oscilloscope, check waveform 3.

      Rear Blower Motor Control Signal
      Item Content
      Terminal No. (Symbol) E36-17 (BLWH) - E36-1 (GND)
      Tool Setting 1 V/DIV., 500 μs/DIV.
      Condition

      Engine switch on (IG)

      Blower switch: Lo

      Tech Tips

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

  2. CHECK AIR CONDITIONING AMPLIFIER ASSEMBLY (w/o Rear Heater)

    B001YP9E02

    1. Disconnect the E81 air conditioning amplifier assembly 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
      E81-21 (+B1) - E81-14 (GND) R - W-B Battery power supply Always 11 to 14 V
      E81-1 (IG+) - E81-14 (GND) G - W-B Ignition power supply Engine switch on (IG) 11 to 14 V
      Engine switch off Below 1 V
      E81-14 (GND) - Body ground W-B - 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. Reconnect the E81 air conditioning amplifier assembly connector.

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

      Terminal No. (Symbol) Wiring Color Terminal Description Condition Specified Condition
      z54-4 (B BUS) - z54-2 (BUS G) - Power supply for BUS IC (for front) Always 11 to 14 V
      E81-35 (SG-5) - Body ground G - Body ground Ground for compressor signal Always Below 1 Ω
      E81-13 (SG-2) - Body ground G - Body ground Ground for pressure sensor Always Below 1 Ω
      E81-34 (SG-1) - Body ground B - Body ground Ground for room temperature sensor (for front) Always Below 1 Ω
      z54-2 (BUS G) - Body ground - Ground for BUS IC (for front) Always Below 1 Ω
      z54-5 (SGA) - Body ground - Ground for evaporator temperature sensor Always Below 1 Ω
      E81-8 (LOCK) - E81-35 (SG-5) L - G Air compressor lock sensor signal

      Engine idling

      A/C switch: On (magnet clutch on)

      Blower switch: Lo

      Pulse generation

      (see waveform 1)
      E81-39 (CFN+) - Body ground*1 R - Body ground Condenser fan operation signal

      Engine switch on (IG)

      A/C switch: Off

      		 Below 1 V

      Engine switch on (IG)

      A/C switch: On

      		 11 to 14 V
      E81-15 (COOL) - Body ground W - Body ground Cool box operation signal

      Engine switch on (IG)

      Cool box switch: Off

      		 Below 1 V

      Engine switch on (IG)

      Cool box switch: On

      		 11 to 14 V
      E81-17 (AC1) - Body ground L - Body ground Compressor operation signal

      Engine switch on (IG)

      Blower switch: Lo

      A/C switch: Off

      		 Below 1 V

      Engine switch on (IG)

      Blower switch: Lo

      A/C switch: On

      		 11 to 14 V
      E81-27 (ACT) - Body ground G - Body ground Compressor operation signal

      Engine switch on (IG)

      Blower switch: Lo

      A/C switch: Off or on (magnet clutch off)

      		 Below 1 V

      Engine switch on (IG)

      Blower switch: Lo

      A/C switch: On (magnet clutch on)

      		 11 to 14 V
      E81-5 (TAM) - E81-13 (SG-2) V - G Ambient temperature sensor signal

      Engine switch on (IG)

      Ambient temperature: 25°C (77°F)

      		 1.6 to 1.8 V

      Engine switch on (IG)

      Ambient temperature: 50°C (122°F)

      		 0.5 to 0.7 V
      E81-30 (S5-1) - E81-13 (SG-2) LG - G Power supply for pressure sensor Engine switch on (IG) 4.5 to 5.5 V
      E81-9 (PRE) - E81-13 (SG-2) R - G Air conditioning pressure sensor signal Refrigerant pressure: Normal 1.0 to 4.8 V

      Refrigerant pressure: Abnormal (less than 0.392 MPa [4.0 kgf/cm2, 57 psi])

      		 Below 1 V

      Refrigerant pressure: Abnormal (less than 3.187 MPa [32.5 kgf/cm2, 463 psi])

      		 4.8 V or higher
      E81-20 (MGC) - E81-14 (GND) R - W-B Compressor magnet clutch operation signal

      Engine idling

      Blower switch: Lo

      A/C switch: On (magnet clutch on permitted)

      		 Below 1 V
      E81-18 (RCRL) - E81-14 (GND) B - Body ground Rear cooler control relay operation signal

      Engine switch on (IG)

      Rear blower switch: Off

      		 Below 1 V

      Engine switch on (IG)

      Rear blower switch: Lo

      		 11 to 14 V
      E81-23 (BLW) - E81-14 (GND) R - W-B Blower motor control signal

      Engine switch on (IG)

      Blower switch: Lo

      Pulse generation

      (see waveform 2)
      E81-29 (TR) - E81-34 (SG-1) W - B Room temperature sensor signal (for front)

      Engine switch on (IG)

      Front side interior temperature: 25°C (77°F)

      		 1.6 to 1.8 V

      Engine switch on (IG)

      Front side interior temperature: 50°C (122°F)

      		 0.5 to 0.7 V
      E81-32 (TSP) - Body ground GR - Body ground Passenger side solar sensor signal

      Engine switch on (IG)

      Solar sensor subjected to electric light

      		 0.8 to 4.3 V
      E81-33 (TSD) - Body ground LG - Body ground Driver side solar sensor signal

      Engine switch on (IG)

      Solar sensor subjected to electric light

      		 0.8 to 4.3 V
      E81-36 (SW1) - Body ground BR - Body ground Idle up operation signal

      Engine switch on (IG)

      Idle up switch: Off

      		 Below 1 V

      Engine switch on (IG)

      Idle up switch: On

      		 11 to 14 V
      z54-6 (TEA) - z54-5 (SGA) - Evaporator temperature sensor signal

      Engine switch on (IG)

      Evaporate temperature: 15°C (59°F)

      		 1.4 to 1.8 V
      z54-3 (BUS) - z54-2 (BUS G) - BUS IC control signal (for front) Engine switch on (IG) Pulse generation
      E81-37 (LIN1) - E81-14 (GND) Y - W-B LIN communication signal Engine switch on (IG) Pulse generation
      E81-25 (ALT) - Body ground R - Body ground Generator signal Engine idling Pulse generation
      E81-3 (PTC1) - Body ground*2 W - Body ground PTC1 heater relay operation signal

      Engine idling

      Set temperature: MAX HOT

      Engine coolant temperature: Below 65°C (149°F)

      Ambient temperature: Below 10°C (50°F)

      		 Below 1 V → 11 to 14 V
      E81-22 (PTC2) - Body ground*2 R - Body ground PTC2 heater relay operation signal
      E81-4 (PTC3) - Body ground*2 R - Body ground PTC3 heater relay operation signal
      E81-24 (MGCA) - E81-14 (GND) Y - W-B Viscous with magnet clutch operation signal

      Engine idling

      Idle up switch: On

      		 Below 1 V

      • *1: w/ Condenser Fan

      • *2: w/ PTC Heater

    5. B001WNQE05

      Using an oscilloscope, check waveform 1.

      Compressor Lock Sensor Signal
      Item Content
      Terminal No. (Symbol) E81-8 (LOCK) - E81-35 (SG-5)
      Tool Setting 200 mV/DIV., 10 ms/DIV.
      Condition

      Engine idling

      Blower switch: Lo

      A/C switch: On

      Tech Tips

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

    6. B001YRCE55

      Using an oscilloscope, check waveform 2.

      Blower Motor Control Signal
      Item Content
      Terminal No. (Symbol) E81-23 (BLW) - E81-14 (GND)
      Tool Setting 1 V/DIV., 500 μs/DIV.
      Condition

      Engine switch on (IG)

      Blower switch: Lo

      Tech Tips

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

  3. CHECK AIR CONDITIONING CONTROL ASSEMBLY (w/o Navigation System)

    B001VQYE04

    1. Disconnect the F10 air conditioning control assembly 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
      F10-7 (IG+) - F10-1 (GND) G - W-B Ignition power supply Engine switch on (IG) 11 to 14 V
      Engine switch off Below 1 V
      F10-1 (GND) - Body ground W-B - 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. Reconnect the F10 air conditioning control assembly connector.

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

      Terminal No. (Symbol) Wiring Color Terminal Description Condition Specified Condition
      F10-12 (DTP+) - F10-1 (GND) R - W-B Temperature up switch signal Temperature up switch not pressed Below 1 V
      Temperature up switch pressed Alternating between 3.5 V or higher and below 1 V
      F10-10 (PTP+) - F10-1 (GND) L - W-B Temperature up switch signal Temperature up switch not pressed Below 1 V
      Temperature up switch pressed Alternating between 3.5 V or higher and below 1 V
      F10-9 (S5) - F10-1 (GND) B - W-B Signal ground Always Below 1 Ω
      F10-11 (DTP-) - F10-1 (GND) G - W-B Temperature down switch signal Temperature down switch not pressed Below 1 V
      Temperature down switch pressed Alternating between 3.5 V or higher and below 1 V
      F10-3 (PTP-) - F10-1 (GND) W - W-B Temperature down switch signal Temperature down switch not pressed Below 1 V
      Temperature down switch pressed Alternating between 3.5 V or higher and below 1 V
      F10-2 (SG) - F10-1 (GND) GR - W-B Signal ground Always Below 1 Ω

  4. CHECK NO. 2 AIR CONDITIONING CONTROL ASSEMBLY

    B001WP9E02

    1. Disconnect the E55 air conditioning control assembly 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
      E55-6 (IG) - E55-1 (E) G - W-B Ignition power supply Always 11 to 14 V
      E55-1 (E) - Body ground W-B - Body ground Ground Always Below 1 Ω

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

  5. CHECK MAIN BODY ECU (COWL SIDE JUNCTION BLOCK LH)

    B001XZME06

    1. Disconnect the 2A, 2B, and 2D 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
      2B-20 (BATB) - Body ground L - Body ground Battery power supply Always 11 to 14 V
      2A-1 (ACC) - Body ground B - Body ground ACC power supply Engine switch on (ACC) 11 to 14 V
      2A-1 (ACC) - Body ground B - Body ground ACC power supply Engine switch off Below 1 V
      2D-62 (GND2) - Body ground W-B - Body ground Ground Always Below 1 Ω

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

  6. MULTI-DISPLAY ASSEMBLY (w/ Navigation System)

    B001XO0E02

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

      Terminal No. (Symbol) Wiring Color Terminal Description Condition Specified Condition
      F90-2 (TEC+) - Body ground R - Body ground Temperature up switch signal Temperature up switch not pressed Below 1 V
      Temperature up switch pressed 3.5 V or higher
      F90-3 (TES+) - Body ground L - Body ground Temperature up switch signal Temperature up switch not pressed Below 1 V
      Temperature up switch pressed 3.5 V or higher
      F90-6 (AGND) - Body ground B - Body ground Signal ground Always Below 1 Ω
      F90-7 (TEC-) - Body ground G - Body ground Temperature down switch signal Temperature down switch not pressed Below 1 V
      Temperature down switch pressed 3.5 V or higher
      F90-8 (TES-) - Body ground W - Body ground Temperature down switch signal Temperature down switch not pressed Below 1 V
      Temperature down switch pressed 3.5 V or higher
      F90-9 (BGND) - Body ground GR - Body ground Signal ground Always Below 1 Ω

  7. MULTI-MEDIA MODULE RECEIVER ASSEMBLY (w/ Navigation System) Click here