Ecu Connector Terminal Identification

WARNING: This page is about a different car, the 2008 Toyota Avalon. However, it is still accessible from the selected car via links, so may be relevant.

CHECK DISTANCE CONTROL ECU

Fig 1: Identifying A20 Connector Terminal

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

VOLTAGE SPECIFICATION

Terminal No. (Symbols)	Wiring Color	Terminal Description	Condition	Specified Condition
A20-1 (B) - A20-12 (GND)	L-B - R	Battery	Always	10 to 14 V
A20-8 (CANH)	L	CAN communication signal	CAN communication circuit	-
A20-9 (CANL)	W	CAN communication signal	CAN communication circuit	-
A20-10 (SGND) - Body ground	LG - Body ground	Ground	Always	Below 1 V
A20-12 (GND) - Body ground	R - Body ground	Ground	Always	Below 1 V
A20-13 (IGB) - A20-12 (GND)	V - R	Ignition switch ON signal	Ignition switch off → on (IG)	Below 1 V → 10 to 14 V
A20-22 (LRDD) - A20-12 (GND)	B - R	Laser sensor input signal	Ignition switch on (IG)	Pulse generation (see awaveform 1)
A20-23 (LRRD) - A20-12 (GND)	G - R	Laser sensor output signal	Ignition switch on (IG)	Pulse generation (see bwaveform 2)

Reference: waveform 1
HINT:
- Terminal: LRDD - GND
- Gauge set: 2 V/DIV, 10 msec./DIV
- Condition: Ignition switch on (IG)
  
  Fig 2: Identifying Waveform 1
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
Reference: waveform 2
HINT:
- Terminal: LRRD - GND
- Gauge set: 2 V/DIV, 5 msec./DIV
- Condition: Ignition switch on (IG)

CHECK ECM

Fig 3: Identifying Waveform 2

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Fig 4: Identifying ECU Connector Terminals

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

VOLTAGE SPECIFICATION

Terminal No. (Symbols)	Wiring Color	Terminal Description	Condition	Specified Condition
A55-36 (STP) - B50-81 (E1)	W - W-B	Stop light signal	Brake pedal released (Stop light switch OFF) → Brake pedal depressed (Stop light switch ON)	Below 1 V → 10 to 14 V
A55-40 (CCS) - B50-81 (E1)	W - W-B	Cruise control main switch signal	Ignition switch on (IG)	10 to 16 V
			CANCEL switch ON	6.6 to 10.1 V
			SET / COAST switch ON	4.5 to 7.1 V
			RES / ACC switch ON	2.3 to 4.0 V
			Main switch ON	Below 1 V
A55-35 (ST1-) - B50-81 (E1)	GR - W-B	Stop light signal	Ignition switch on (IG) Brake pedal depressed (Stop light switch ON) → Brake pedal released (Stop light switch OFF)	Below 1 V → 10 to 14 V
A55-37 (CCHG) - B50-81 (E1)	O - W-B	Distance control switch signal	Ignition switch on (IG) Cruise control main switch ON MODE switch ON → MODE switch OFF	Below 1 V → 10 to 14 V
A55-38 (LGND) - Body ground	BR - Body ground	Ground	Always	Below 1 V
B50-81 (E1)-Body ground	W-B - Body ground	Ground	Always	Below 1 V

If the value is not within the standard range, some defects on the vehicle are suspected.

CHECK LASER SENSOR

Fig 5: Identifying A36 Connector Terminal

VOLTAGE AND RESISTANCE SPECIFICATION

Terminal No. (Symbols)	Wiring Color	Terminal Description	Condition	Specified Condition
A36-1 (LGND) - Body ground	BR - Body ground	Distance signal	Always	Below 1 Ω
A36-2 (SGND) - Body ground	O - Body ground	Ground	Always	Below 1 Ω
A36-3 (LRDD) - A36-2 (SGND)	B - O	Laser sensor output signal	Ignition switch: on (IG)	Pulse generation (see awaveform 1)
A36-4 (LRRD) - A36-2 (SGND)	G - 0	Laser sensor input signal	Ignition switch: on (IG)	Pulse generation (see bwaveform 2)
A36-5 (IGB) - A36-2 (SGND)	V - O	Ignition switch signal	Ignition switch: on (IG)	10 to 14 V

Reference: waveform 1
HINT:
- Terminal: LRDD - SGND
- Gauge set: 1 V/DIV, 2 msec./DIV
- Condition: Ignition switch on (IG)
  
  Fig 6: Identifying Waveform 1
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
Reference: waveform 2
HINT:
- Terminal: LRRD - SGND
- Gauge set: 1 V/DIV, 2 msec./DIV
- Condition: Ignition switch on (IG)
  
  Fig 7: Identifying Waveform 2
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002