CLIMATE CONTROL SEAT SYSTEM TERMINALS OF ECU


  1. AIR CONDITIONING AMPLIFIER ASSEMBLY

    A01FR9HE08

    1. Disconnect the N78 air conditioning amplifier assembly connector.

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

      Tech Tips

      Measure the values on the wire harness side with the connector disconnected.

      Terminal No. (Symbol) Wiring Color Terminal Description Condition Specified Condition
      N78-6 (+B1) - Body ground W - Body ground Power source (Back-up) Always 11 to 14 V
      N78-5 (IG+) - Body ground L - Body ground Power source (IG) Power switch on (IG) 11 to 14 V
      N78-1 (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 N78 air conditioning amplifier assembly connector.

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

      Terminal No. (Symbol) Wiring Color Terminal Description Condition Specified Condition
      N78-10 (LOUT) - N78-1 (GND) V - W-B Output climate control signal (for LH side) Power switch on (IG), refreshing seat switch LH on (blower on)

      Pulse generation

      (See waveform)
      N78-11 (ROUT) - N78-1 (GND) L - W-B Output climate control signal (for RH side) Power switch on (IG), refreshing seat switch RH on (blower on)

      Pulse generation

      (See waveform)
      N78-20 (LIN1) - N78-1 (GND) R - W-B LIN communication signal Power switch on (IG) Pulse generation

      1. A01FT28E06

        Waveform (Reference): Using an oscilloscope:

        Item Content
        Tester Connection

        N78-11 (ROUT) - N78-1 (GND)

        N78-10 (LOUT) - N78-1 (GND)
        Tool Setting 2 V/DIV., 500 μsec/DIV.
        Vehicle Condition Power switch on (IG), refreshing seat switch on

  2. CHECK REFRESHING SEAT SWITCH

    A01FU31E04

    1. Disconnect the N72 refreshing seat switch 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
      N72-7 (IG+) - Body ground LG - Body ground Power source (IG) Power switch on (IG) 11 to 14 V
      N72-4 (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.

    3. Reconnect the N72 refreshing seat switch connector.

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

      Terminal No. (Symbol) Wiring Color Terminal Description Condition Specified Condition
      N72-7 (SW) - N72-4 (E) R - W-B LIN communication signal Power switch on (IG) Pulse generation