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


  1. CHECK AIR CONDITIONING AMPLIFIER ASSEMBLY

    B001ZRTE02

    1. Disconnect the E81 air conditioning amplifier assembly 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
      E81-21 (+B1) - E81-14 (GND) LG - BR Battery power supply Always 11 to 14 V
      E81-1 (IG+) - E81-14 (GND) G - BR Ignition power supply Ignition switch ON 11 to 14 V
      Ignition switch off Below 1 V
      E81-14 (GND) - Body ground BR - Body ground Ground Always Below 1 Ω

    3. Reconnect the E81 air conditioning amplifier assembly connector.

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

      Terminal No. (Symbol) Wiring Color Terminal Description Condition Specified Condition
      E81-3 (PTC2) - Body ground*2 B - Body ground Quick heater assembly operation signal

      • Engine idling

      • Set temperature: MAX HOT (HI)

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

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

      • Blower switch: off → on (after 30 seconds)

      		 11 to 14 V → Below 1 V
      E81-4 (SW 1) - Body ground*1 P - Body ground Idle up switch operation signal

      • Engine running

      • A/C switch on

      • Blower switch on (LO level)

      • Idle up switch off → on

      		 Below 1 V 14 V
      E81-5 (TAM) - E81-13 (SG-2) V - G Ambient temperature sensor signal

      • Ignition switch ON

      • Ambient temperature: 25°C (77°F)

      		 1.4 to 1.6 V

      • Ignition switch ON

      • Ambient temperature: 50°C (122°F)

      		 0.7 to 0.9 V
      E81-8 (LOCK) - E81-13 (SG-2) L - G Compressor lock sensor signal

      • Engine idling

      • A/C switch on (magnet clutch on)

      • Blower switch: LO

      Pulse generation

      (see waveform 1)
      E81-9 (PRE) - E81-13 (SG-2) R - G Air conditioning pressure sensor signal

      • Ignition switch ON

      • A/C switch off

      		 0.63 to 4.78 V

      • Engine idling

      • A/C switch on

      • Blower switch LO

      • Refrigerant pressure is normal

      		 0.63 to 4.78 V

      Refrigerant pressure: Abnormal (less than 177 kPa [1.8 kgf/cm2, 26 psi])

      		 Below 0.63 V

      Refrigerant pressure: Abnormal (more than 3079 kPa [31.4 kgf/cm2, 446 psi])

      		 4.78 V or higher
      E81-13 (SG-2) - Body ground G - Body ground Ground for pressure sensor, cooler compressor Always Below 1 Ω
      E81-17 (MGCA) - Body ground*1 P - Body ground Viscous with magnet clutch operation signal

      • Engine idling

      • Idle up switch on

      		 Below 1 V
      E81-20 (MGC) - E81-14 (GND) R - BR Magnet clutch operation signal

      • Engine idling

      • Blower switch: LO

      • A/C switch on (magnet clutch on)

      		 Below 1 V

      • Engine idling

      • Blower switch: LO

      • A/C switch on or off (magnet clutch off)

      		 11 to 14 V
      E81-22 (BLW) - E81-14 (GND) R - BR Blower motor control signal

      • Ignition switch ON

      • Blower switch: LO

      Pulse generation

      (see waveform 2)

      • Ignition switch ON

      • Blower switch: off

      		 4.5 to 5.5 V
      E81-23 (AC1) - Body ground L - Body ground Compressor operation signal

      • Engine idling

      • Blower switch LO

      • A/C switch off

      		 11 to 14 V

      • Engine idling

      • Blower switch LO

      • A/C switch on

      		 Below 1 V
      E81-24 (COOL) - Body ground*4 W - Body ground Cool box operation signal

      • Ignition switch ON

      • Cool box switch on

      		 Below 1 V

      • Ignition switch ON

      • Cool box switch off

      		 11 to 14 V
      E81-25 (ALT) - Body ground R - Body ground Generator assembly signal Ignition switch ON Pulse generation
      E81-27 (ACT) - Body ground G - Body ground Compressor operation signal

      • Engine idling

      • A/C switch off or on (magnet clutch off)

      		 Below 1 V

      • Engine idling

      • A/C switch on (magnet clutch on)

      		 11 to 14 V
      E81-30 (S5-3) - E81-13 (SG-2) LG - G Power supply for air conditioner pressure Ignition switch ON 4.75 to 5.25 V
      E81-36 (PTC3) - Body ground*2 R - Body ground Quick heater assembly operation signal

      • Engine idling

      • Set temperature: MAX HOT (HI)

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

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

      • Blower switch: off → on (after 20 seconds)

      		 11 to 14 V → Below 1 V
      E81-40 (PTC1) - Body ground*2 W - Body ground Quick heater assembly operation signal

      • Engine idling

      • Set temperature: MAX HOT (HI)

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

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

      • Blower switch: off → on (after 10 seconds)

      		 11 to 14 V → Below 1 V
      z71-2 (BUS G) - Body ground - Ground for BUS IC Always Below 1 Ω
      z71-3 (BUS) - z71-2 (BUS G) - BUS IC control signal Ignition switch ON Pulse generation
      z71-4 (B BUS) - z71-2 (BUS G) - Power supply for BUS IC Always 11 to 14 V
      z71-5(SG) - Body ground - Ground for evaporator temperature sensor Always Below 1 Ω
      z71-5 (SG) - z71-6 (TE) - Evaporator temperature sensor signal

      • Ignition switch ON

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

      		 1.0 to 1.2 V

      • *1: w/ Viscous Heater

      • *2: w/ PTC Heater

    5. B001WNQE05

      Using an oscilloscope, check waveform 1.

      Compressor Lock Sensor Signal
      Item Content
      Terminal No. (Symbol) E81-8 (LOCK) - E81-13 (SG-2)
      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) E81-22 (BLW) - E81-14 (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.

  2. CHECK AIR CONDITIONING CONTROL ASSEMBLY

    B001VQYE05

    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) B - W-B Ignition power supply Ignition switch ON 11 to 14 V
      Ignition switch off Below 1 V
      F10-1 (GND) - Body ground W-B - Body ground Ground Always Below 1 Ω