Terminals Of Ecu

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

CHECK OCCUPANT CLASSIFICATION ECU

ECU TERMINAL REFERENCE TABLE

Terminal No. (Symbols)	Wiring Color	Terminal Description	Condition	Specification
Y2-1 (+B) - Y2-3 (GND)1 Q11-1 (+B) - Q11-3 (GND)2	R - W-B	Battery	Ignition switch ON	11 to 14 V
Y2-2 (DIA) - Y2-3 (GND)1 Q11-2 (DIA) - Q11-3 (GND)2	BR - W-B	Diagnosis (DLC3)	Ignition switch ON	Pulse generation
Y2-3 (GND) - Body ground1 Q11-3 (GND) - Body ground2	W-B - Body ground	Ground	Always	Below 1 Ω
Y2-4- (FSR-) - Y2-3 (GND)1 Q11-4- (FSR-) - Q11-3 (GND)2	B - W-B	Center airbag sensor communication ground line	Always	Below 1 Ω
Y2-5 (BGND) - Y2-3 (GND)1 Q11-5 (BGND) - Q11-3 (GND)2	O - W-B	Passenger side buckle switch ground line	Always	Below 1 Ω
Y2-7 (IG) - Y2-3 (GND)1 Q11-7 (IG) - Q11-3 (GND)2	SB - W-B	Power source (IGN fuse)	Ignition switch ON	11 to 14 V
Y2-8 (FSR+) - Y2-4 (FSR-)1 Q11-8 (FSR+) - Q11-4 (FSR-)2	W - B	Center airbag sensor communication line	Ignition switch ON	Pulse generation
Y2-9 (BSW) - Y2-5 (BGND)1 Q11-9 (BSW) - Q11-5 (BGND)2	L - O	Passenger side buckle switch line	Buckle switch ON	0.12 to 0.18 A
Y2-9 (BSW) - Y2-5 (BGND)1 Q11-9 (BSW) - Q11-5 (BGND)2	L - O	Passenger side buckle switch line	Buckle switch OFF	0.4 to 0.7 mA
Y1-1 (SGD1) - Y2-3 (GND)1 Y1-1 (SGD1) - Q11-3 (GND)2	Y - W-B	Front occupant detection sensor LH ground line	Always	Below 1 Ω
Y1-2 (SGD2) - Y2-3 (GND)1 Y1-2 (SGD2) - Q11-3 (GND)2	SB - W-B	Front occupant detection sensor RH ground line	Always	Below 1 Ω
Y1-3 (SGD3) - Y2-3 (GND)1 Y1-3 (SGD3) - Q11-3 (GND)2	L - W-B	Rear occupant detection sensor LH ground line	Always	Below 1 Ω
Y1-4 (SGD4) - Y2-3 (GND)1 Y1-4 (SGD4) - Q11-3 (GND)2	W - W-B	Rear occupant detection sensor RH ground line	Always	Below 1 Ω
Y1-11 (SVC1) - Y1-1 (SGD1)	P - Y	Front occupant detection sensor LH power supply line	Ignition switch ON, load is applied to front occupant detection sensor LH	4.5 to 5.1 V
Y1-12 (SVC2) - Y1-2 (SGD2)	BR - SB	Front occupant detection sensor RH power supply line	Ignition switch ON, load is applied to front occupant detection sensor RH	4.5 to 5.1 V
Y1-5 (SVC3) - Y1-3 (SGD3)	R - L	Rear occupant detection sensor LH power supply line	Ignition switch ON, load is applied to rear occupant detection sensor LH	4.5 to 5.1 V
Y1-6 (SVC4) - Y1-4 (SGD4)	B - W	Rear occupant detection sensor RH power supply line	Ignition switch ON, load is applied to rear occupant detection sensor RH	4.5 to 5.1 V
Y1-7 (SIG1) - Y1-1 (SGD1)	O - Y	Front occupant detection sensor LH signal line	Ignition switch ON, load is applied to front occupant detection sensor LH	Pulse generation
Y1-8 (SIG2) - Y1-2 (SGD2)	GR - SB	Front occupant detection sensor RH signal line	Ignition switch ON, load is applied to front occupant detection sensor RH	Pulse generation
Y1-9 (SIG3) - Y1-3 (SGD3)	G - L	Rear occupant detection sensor LH signal line	Ignition switch ON, load is applied to rear occupant detection sensor LH	Pulse generation
Y1-10 (SIG4) - Y1-4 (SGD4)	V - W	Rear occupant detection sensor RH signal line	Ignition switch ON, load is applied to rear occupant detection sensor RH	Pulse generation
HINT: 1: for Power Seat 2: for Manual Seat

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

Fig 1: Identifying Occupant Classification ECU Terminals