PRE-COLLISION SYSTEM TERMINALS OF ECU

CHECK DRIVING SUPPORT ECU ASSEMBLY

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

   Terminal No. (Symbol)	Wiring Color	Terminal Description	Condition	Specified Condition
   H185-7 (B) - H185-28 (GND)	BE - W-B	Power source	Power switch on (IG)	11 to 14 V
   			Power switch off	Below 1 V
   H185-3 (BZ) - H185-28 (GND)	V - W-B	Skid control buzzer assembly output	Power switch on (IG), buzzer not sounding	11 to 14 V
   			Power switch on (IG), buzzer sounding	Below 1 V
   H185-28 (GND) - Body ground	W-B - Body ground	Ground	Always	Below 1 Ω

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

   Tech Tips

   If the waveform is not similar to that shown in the illustration, a malfunction of a CAN bus line, terminating resistor, or the driving support ECU assembly is suspected.

   Terminal No. (Symbol)	Wiring Color	Terminal Description	Condition	Specified Condition
   H185-8 (CA1P) - H185-28 (GND)	LG - W-B	CAN communication signal	Power switch on (IG)	Pulse generation (See waveform 1)
   H185-9 (CA1N) - H185-28 (GND)	W - W-B	CAN communication signal	Power switch on (IG)	Pulse generation (See waveform 2)
   H185-10 (CA2H) - H185-28 (GND)	L - W-B	CAN communication signal	Power switch on (IG)	Pulse generation (See waveform 1)
   H185-11 (CA2L) - H185-28 (GND)	B - W-B	CAN communication signal	Power switch on (IG)	Pulse generation (See waveform 2)

   
   
   1. 

      *a	1 V/DIV.
      *b	10 μsec./DIV.

      WAVEFORM 1

      Item	Content
      Terminal Name	Between H185-8 (CA1P) - H185-28 (GND) Between H185-10 (CA2H) - H185-28 (GND)
      Tester Range	1 V/DIV., 10 μsec./DIV.
      Condition	Power switch on (IG)

      Tech Tips

      The waveform varies depending on the CAN communication signal.

   2. 

      *a	1 V/DIV.
      *b	10 μsec./DIV.

      WAVEFORM 2

      Item	Content
      Terminal Name	Between H185-9 (CA1N) - H185-28 (GND) Between H185-11 (CA2L) - H185-28 (GND)
      Tester Range	1 V/DIV., 10 μsec./DIV.
      Condition	Power switch on (IG)

      Tech Tips

      The waveform varies depending on the CAN communication signal.

CHECK MILLIMETER WAVE RADAR SENSOR ASSEMBLY

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

   Terminal No. (Symbol)	Wiring Color	Terminal Description	Condition	Specified Condition
   k1-8 (IGB) - k1-1 (SGND)	BR - W-B	Power source	Power switch on (IG)	11 to 14 V
   k1-1 (SGND) - Body ground	W-B - Body ground	Ground	Always	Below 1 Ω

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

   Tech Tips

   If the waveform is not similar to that shown in the illustration, a malfunction of a CAN bus line, terminating resistor, or the millimeter wave radar sensor assembly is suspected.

   Terminal No. (Symbol)	Wiring Color	Terminal Description	Condition	Specified Condition
   k1-3 (CA2H) - k1-1 (SGND)	R - W-B	CAN communication signal	Power switch on (IG)	Pulse generation (See waveform 1)
   k1-2 (CA2L) - k1-1 (SGND)	W - W-B	CAN communication signal	Power switch on (IG)	Pulse generation (See waveform 2)
   k1-5 (CA1P) - k1-1 (SGND)	LG - W-B	CAN communication signal	Power switch on (IG)	Pulse generation (See waveform 1)
   k1-6 (CA1N) - k1-1 (SGND)	W - W-B	CAN communication signal	Power switch on (IG)	Pulse generation (See waveform 2)

   
   
   1. 

      *a	1 V/DIV.
      *b	10 μsec./DIV.

      WAVEFORM 1

      Item	Content
      Terminal Name	Between k1-3 (CA2H) and k1-1 (SGND) Between k1-5 (CA1P) and k1-1 (SGND)
      Tester Range	1 V/DIV., 10 μsec./DIV.
      Condition	Power switch on (IG)

      Tech Tips

      The waveform varies depending on the CAN communication signal.

   2. 

      *a	1 V/DIV.
      *b	10 μsec./DIV.

      WAVEFORM 2

      Item	Content
      Terminal Name	Between k1-2 (CA2L) and k1-1 (SGND) Between k1-6 (CA1N) and k1-1 (SGND)
      Tester Range	1 V/DIV., 10 μsec./DIV.
      Condition	Power switch on (IG)

      Tech Tips

      The waveform varies depending on the CAN communication signal.