Terminals Of Ecu

Fig 1: Identifying Terminals Of ECU

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

1. Disconnect the M21 display connector.
2. Measure the resistance and voltage according to the value(s) in the table below.
   MULTI-DISPLAY RESISTANCE AND VOLTAGE
   
   

   Terminal No. (Symbols)	Wiring Color	Terminal Description	Condition	Specified Condition
   M21-3 (+B1) - M21-1 (GND1)	R-L - BR	Battery	Always	11 to 14 V
   M21-2 (ACC) - M21-1 (GND1)	GR - BR	Accessory (ON)	Ignition switch OFF	Below 1 V
   M21-2 (ACC) - M21-1 (GND1)	GR - BR	Accessory (ON)	Ignition switch ACC	11 to 14 V
   M21-10 (IG) - M21-1 (GND1)	B-R - BR	Ignition (ON)	Ignition switch OFF	Below 1 V
   M21-10 (IG) - M21-1 (GND1)	V - BR	Ignition (ON)	Ignition switch ON	11 to 14 V
   M21-1 (GND1) - Body ground	BR - 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 M21 display connector.
4. Measure the voltage according to the value(s) in the table below.
   MULTI-DISPLAY VOLTAGE
   
   

   Terminal No. (Symbols)	Wiring Color	Terminal Description	Condition	Specified Condition
   M21-7 (TC) - M21-1 (GND1)	P-L - BR	Diagnosis ON signal	Ignition switch ON	9 to 14 V
   M21-11 (ILL-) - M21-1 (GND1)	W-B - BR	Illumination signal	Light control switch OFF	Below 1 V
   M21-11 (ILL-) - M21-1 (GND1)	W-B - BR	Illumination signal	Light control switch ON	11 to 14 V
   M21-12 (ILL+) - M21-1 (GND1)	G - BR	Illumination signal	Light control switch OFF	Below 1 V
   M21-12 (ILL+) - M21-1 (GND1)	G - BR	Illumination signal	Light control switch ON	11 to 14 V
   M21-17 (DR) - M21-1 (GND1)	R - BR	Dimmer signal	Ignition switch ON, light control switch ON and automatic light control sensor covered by hand	Above 9 V
   M21-19 (SPD) - M21-1 (GND1)	V-R - BR	Speed signal from combination meter	See  6 "Vehicle Signal Check" Mode	-
   M21-8 (PKB) - M21-1 (GND1)	LG - BR	Parking brake signal	See  6 "Vehicle Signal Check" Mode	-
   M20-8 (TSW-) - M21-1 (GND1)	W-B - BR	Telephone relation switch signal	Always	Below 1 V
   M20-4 (MACC) - M21-1 (GND1)*1	B-L - BR	Microphone amplifier power supply	Ignition switch OFF	Below 1 V
   M20-4 (MACC) - M21-1 (GND1)*1	B-L - BR	Microphone amplifier power supply	Ignition switch ON	5 V
   M20-3 (MIN-) - M21-1 (GND1)	G - BR	Microphone voice signal	See  8 "Microphone & Voice Recognition Check"	-
   M20-2 (MIN+) - M21-1 (GND1)	R - BR	Microphone voice signal	See  8 "Microphone & Voice Recognition Check"	-
   M20-1 (SGND) - M21-1 (GND1)	W-B - BR	Signal ground	Always	Below 1 V
   M20-26 (IVO-) - M21-1 (GND1)	P - BR	Voice guidance signal	Voice guidance is provided	Waveform synchronized with sounds is output
   M20-25 (IVO+) - M20-10 (GND1)	L - BR	Voice guidance signal	Voice guidance is provided	Waveform synchronized with sounds is output
   M20-24 (SLD) - M21-1 (GND1)	Shielded - BR	Shielded ground	Always	Below 1 V
   M22-5 (SGD1) - M21-1 (GND1)	Shielded - BR	Shielded ground	Always	Below 1 V
   M22-1 (NTSC) - M21-1 (GND1)	Y - BR	DVD image signal	DVD is played on disc player changer	Pulse generation
   M22-4 (SG) - M21-1 (GND1)	BR - BR	DVD image signal ground	Always	Below 1 V
   M21-18 (TX2+) - M21-1 (GND1)	L - BR	AVC-LAN communication signal	Ignition switch ACC	2 to 3 V
   M21-19 (TX2-) - M21-1 (GND1)	LG - BR	AVC-LAN communication signal	Ignition switch ACC	2 to 3 V
   M21-4 (TX1+) - M21-1 (GND1)	G - BR	AVC-LAN communication signal	Ignition switch ACC	2 to 3 V
   M21-5 (TX1-) - M21-1 (GND1)	R - BR	AVC-LAN communication signal	Ignition switch ACC	2 to 3 V
   M22-3 (TX4+) - M21-1 (GND1)	B - BR	AVC-LAN communication signal	Ignition switch ACC	2 to 3 V
   M22-6 (TX4-) - M21-1 (GND1)	W - BR	AVC-LAN communication signal	Ignition switch ACC	2 to 3 V
   M20-10 (TX-) - M21-1 (GND1)	R - BR	AVC-LAN communication signal	Ignition switch ACC	2 to 3 V
   M20-9 (TX+) - M21-1 (GND1)	G - BR	AVC-LAN communication signal	Ignition switch ACC	2 to 3 V
   M20-21 (SGND) - M21-1 (GND1)	Shielded - BR	Shielded ground	Always	Below 1 V
   M20-23 (MCO-) - M21-1 (GND1)	Y - BR	Microphone voice signal	See  8 "Microphone & Voice Recognition Check"	-
   M20-22 (MCO+) - M21-1 (GND1)	BR - BR	Microphone voice signal	See  8 "Microphone & Voice Recognition Check"	-
   M20-6 (IVI-) - M21-1 (GND1)	W - BR	Voice guidance signal	Voice guidance is provided	Waveform synchronized with sounds is input
   M20-5 (IVI+) - M21-1 (GND1)	B - BR	Voice guidance signal	Voice guidance is provided	Waveform synchronized with sounds is input
   M23-1 (GVIF) - M21-1 (GND1)	B - BR	Television camera digital image signal	Ignition switch ON, shift lever in R position	Pulse generation
   HINT: (1) w/o LEXUS Link System

   If the result is not as specified, the multi-display may have a malfunction.

5. Using an oscilloscope, check the waveform 1.
Fig 2: Identifying Signal Waveform
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Waveform 1 (reference) 

Fig 3: Identifying Navigation ECU Connector Terminals

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

1. Disconnect the N8 ECU connector.
2. Measure the resistance and voltage according to the value(s) in the table below.
   NAVIGATION ECU RESISTANCE AND VOLTAGE
   
   

   Terminal No. (Symbols)	Wiring Color	Terminal Description	Condition	Specified Condition
   N8-15 (GND) - Body ground	BR - Body ground	Ground	Always	Below 1 Ω
   N8-1 (+B) - N8-15 (GND)	L-Y - BR	Battery	Always	11 to 14 V
   N8-13 (ACC) - N8-15 (GND)	GR - BR	Accessory (ON)	Ignition switch OFF	Below 1 V
   N8-13 (ACC) - N8-15 (GND)	GR - BR	Accessory (ON)	Ignition switch ACC	11 to 14 V

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

3. Reconnect the N8 ECU connector.
4. Measure the voltage according to the value(s) in the table below.

If the result is not as specified, the ECU may have a malfunction.