WINDOW DEFOGGER SYSTEM TERMINALS OF ECU


  1. CHECK AIR CONDITIONING AMPLIFIER ASSEMBLY


    1. Disconnect the E28 air conditioning amplifier assembly connector.

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    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.

      Tester Connection Wiring Color Terminal Description Condition Specified Condition
      E28-1 (IG+) - E28-14 (GND) L - BR Power source (IG) Ignition switch ON 11 to 14 V
      E28-1 (IG+) - E28-14 (GND) L - BR Power source (IG) Ignition switch off Below 1 V
      E28-21 (B) - E28-14 (GND) W - BR Battery power supply Always 11 to 14 V
      E28-14 (GND) - Body ground BR - Body ground Ground Always Below 1 Ω

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

    3. Reconnect the E28 air conditioning amplifier assembly connector.

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

      Tester Connection Wiring Color Terminal Description Condition Specified Condition
      E28-38 (RDFG) - E28-14 (GND) V - BR Rear window defogger signal Ignition switch ON, rear window defogger switch off 11 to 14 V
      E28-38 (RDFG) - E28-14 (GND) V - BR Rear window defogger signal Ignition switch ON, rear window defogger switch on Below 1 V
      E28-37 (LIN1) - E28-14 (GND) SB - BR LIN communication line Ignition switch ON Pulse generation

      If the result is not as specified, the air conditioning amplifier assembly may be malfunctioning.

  2. CHECK AIR CONDITIONING CONTROL ASSEMBLY


    1. Disconnect the E71 air conditioning control assembly connector.

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    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.

      Tester Connection Wiring Color Terminal Description Condition Specified Condition
      E71-8 (IG+) - E71-5 (GND) B - W-B Power source (IG) Ignition switch ON 11 to 14 V
      E71-8 (IG+) - E71-5 (GND) B - W-B Power source (IG) Ignition switch off Below 1 V
      E71-5 (GND) - Body ground W-B - Body ground Ground Always Below 1 Ω

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

    3. Reconnect the E71 air conditioning control assembly connector.

    4. Check for pulses according to the value(s) in the table below.

      Tester Connection Wiring Color Terminal Description Condition Specified Condition
      E71-6 (LIN1) - E71-5 (GND) SB - W-B LIN communication line Ignition switch ON Pulse generation

      If the result is not as specified, the air conditioning control assembly may be malfunctioning.