Terminals Of Ecu

HINT:

Inspect the connector from the back side while connector is connected.

4WD CONTROL ECU:

Fig 1: Identifying 4WD Control ECU U52 Connector Terminals

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Symbols (Terminal No.)	Wiring Color	Terminal Description	Condition	Specified Condition
CANH (U52-1) - CANL (U52-14)	W-B	CAN communication line	Engine switch off	54 to 67 Ω
RRO (U52-2) - GND (U52-30)	P - W-B	Rear right wheel speed sensor signal	Engine switch on (IG), driving at approximately 18 mph (30 km/h)	Pulse generation (see waveform 1 in Fig 2)
FRO (U52-3) - GND (U52-30)	G - W-B	Front right wheel speed sensor signal	Engine switch on (IG), driving at approximately 18 mph (30 km/h)	Pulse generation (see waveform 1 in Fig 2)
IG1 (U52-9) - GND (U52-30)	B - W-B	Power source voltage	Engine switch on (IG)	10 to 14 V
SLC+ (U52-13) - SLC- (U52-32)	V - O	Transfer control solenoid signal	Engine switch on (IG)	Pulse generation (see waveform 2 in Fig 3)
RLO (U52-15) - GND (U52-30)	L - W-B	Rear left wheel speed sensor signal	Engine switch on (IG), driving at approximately 18 mph (30 km/h)	Pulse generation (see waveform 1 in Fig 2)
FLO (U52-16) - GND (U52-30)	R - W-B	Front left wheel speed sensor signal	Engine switch on (IG), driving at approximately 18 mph (30 km/h)	Pulse generation (see waveform 1 in Fig 2)
FREE (U52-23) - GND (U52-30)	GR - W-B	Sets the center differential free	Engine switch on (IG), open and short terminals OPA and CG of the DLC3.	10 to 14 V → 0 to 1.5 V
GND (U52-30) - Body ground	W-B - Body ground	Ground	Always	Below 1 Ω

Waveform 1 (Reference):

Fig 2: Identifying Waveform 1

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Item	Contents
Tool setting	2 V/DIV, 2 ms/DIV
Vehicle condition	Driving at approximately 18 mph (30 km/h)

HINT:

As vehicle speed (wheel rotation speed) increases, the width of the waveform narrows.

Waveform 2 (Reference):

Fig 3: Identifying Waveform 2

Item	Contents
Tool setting	5 V/DIV, 2 ms/DIV
Vehicle condition	Engine stop, Engine switch on (IG)