COMBUSTION TYPE POWER HEATER SYSTEM TERMINALS OF ECU

  1. INSPECT HEATER ASSEMBLY

    E124453N01

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

      Terminal No. (Symbol)

      Wiring Color

      Terminal Description

      Condition

      Specified Condition

      A42-1 (E) - Body ground

      W-B - Body ground

      Ground for main power supply

      Always

      Below 1 Ω

      A42-2 (L) - Body ground

      G - Body ground

      Fuel pump operation signal

      Engine running

      Heater switch assembly: On

      Pulse generation

      (See waveform 1)

      A42-3 (IG) - Body ground

      Y - Body ground

      Power heater operating signal

      Ignition switch ON

      Heater switch assembly: On

      11 to 14 V

      A42-3 (IG) - Body ground

      Y - Body ground

      Power heater operating signal

      Ignition switch off

      Heater switch assembly: Off

      Below 1 V

      A42-5 (B) - Body ground

      W - Body ground

      Power source

      Always

      11 to 14 V

      A42-8 (+) - Body ground

      Y - Body ground

      Engine operating signal

      Engine running

      (Generator assembly: Operating)

      11 to 14 V
    2. E130372N01

      Waveform 1:

      Table 1. Heater Fuel Pump Control Signal

      Item

      Content

      Terminal No. (Symbol)

      A42-2 (L) - Body ground

      Tool Setting

      2 V/DIV., 20 ms/DIV.

      Vehicle Condition

      Engine running

      Heater switch assembly: On