4WD (Double Cab)

(IG) (IG) (IG)

F20(A), F21(B)
4WD Control ECU
15A 10A 20A
GAUGE IGN1 4WD

7
11 1H 8 1D
IPO IG IND3 LO 2–4
8 5 A 11 A 15 A 8 A
B–O

L–Y
7 1D

G–Y
P–B
L–Y

P
L–B

C11(A), C12(B)
24 B Combination Meter

4LO
4HI

SPEED
CONTROL

26 IE1
12 B 24 A 25 A 4 B 5 B 7 B 6 B

P–B
W–B

V–W

G–O

Y–B

Y–B

P–B
L

P1

G–Y
Park/Neutral

P
2 Position SW

Integration Control and Panel

N
6 A 18 A
Skid Control ECU with Actuator (∗1)
ABS Actuator with ECU (∗2)

9 H–L 2–4

I24(A), I25(B)
LG–B

L4 4WD E
19 A 20 A 10 B
J28(A), J29(B)

J49(A), J50(B)

G A D A
W–B
P–B

Y–B
Connector

Connector

6 1D
Junction

Junction

10 4B
G B E B
LG–B

9 1F
10 4D
Y–B Y–B

G–O

LG–B
W–B

A
J45 W–B
Junction
Connector

IO

456

TOYOTA TUNDRA (EM00Q0U)

 Y–B

G–O

W–B
LG–B
Y–B

19 A
IND1
LG–B

22 A
N
G–O G–O G–O

E B
D A
9 A
SPD

A
A
W–B W–B W–B W–B

D B
E A
6 A

IN
GND

J58
E A
J55(A), J56(B)
Junction Connector

Junction Connector
W–B
F20(A), F21(B)
4WD Control ECU

6 IE4
D3

W–B
Detection SW
(Transfer 4WD Position)

1
2
W–B G–R G–R
22 B

9 IE4
4WD

D4 J64
Detection SW Junction

W–B
(Transfer L4 Position) Connector

1
2
B
W–B L–R B L–R L–R
11 IE4

W–B
GR L–R L–R
C A

8 C
13 C
L4

4WD

TOYOTA TUNDRA (EM00Q0U)

E 5(C)
Engine Control Module

6
7

24
38
GR L–R L–R L–R
A B
C A
17 B
L4

IJ4
IJ4

EXI
EXI4
(∗2) (∗2) (∗2)
∗ 1 : w/ VSC

J55(A), J56(B)
∗ 2 : w/o VSC

A5 Junction
ABS Actuator with ECU Connector

6
7

GR L–R L–R

27 A
21 A

IJ4
IJ4

EXI
EXI4
(∗1) (∗1) (∗1)

S29(A)
Skid Control ECU

GR
with Actuator

W–B
GR(∗2)
GR(∗1)

457
4WD (Double Cab)
∗ 1 : w/ VSC
∗ 2 : w/o VSC

F20(A), F21(B)
4WD Control ECU

ADD DL1 DL2 DM1 DM2 TM2 TM1 TL3 TL1 TL2
26 B 13 A 21 A 2 A 1 A 1 B 2 B 23 B 25 B 24 B
GR

B A B A
J55(A), J56(B)

R–W

B–W
B–R
R–B
GR

LG
Connector

G
R

L
Junction

B B
GR(∗1)

GR(∗2)

H B
J28(A), J29(B)

3 IE4 8 IE4 4 IE4 12 IE4 13 IE4 5 IE4 1 IE4 2 IE4 7 IE4

Connector
Junction

F A F A
R–W

R–B
LG

R
GR

GR

B–W
B–R

W
G
Y

3 EC1 2 EC1 6 EC1 1 EC1 5 EC1

R–W

R–B
GR

LG

1 ED1 2 ED1 4 ED1 3 ED1 5 ED1

2 3 5 6
R–W

R–B
GR

LG

3 6 2 5 1 H2
Detection SW

M H4
M

4 A9 L4
GR(∗1) ADD Actuator
W–B

GR(∗2) T3
1 4
Transfer Shift Actuator
GR 6 ED1
4
W–B W–B W–B
W–B

EC1

W–B

458

TOYOTA TUNDRA (EM00Q0U)

 System Outline
In the conventional system, the 2–4 select SW and the transfer shift lever was used to shift the mode between H–L. In this
system, the transfer shift lever is not used, and the H–L mode shift can be done by the transfer shift actuator.
The mode can be changed by the touch select 2–4 SW and touch select high–low in the integration control and panel.
The shift range is controlled according to the vehicle speed sensor and Park/Neutral position SW, and the indicator light is
turned ON to inform the driver if any of the following conditions are detected:
∗ The shift is not completed even though 3 seconds have elapsed after transfer operation.
∗ The vehicle speed is above approximately 100 km/h (63 mph) when shifting from H2 to H4.
∗ The vehicle speed is below approximately 5 km/h (3 mph) or the A/T shift lever is in a position other than N position, when
shifting from H4 to L4 or visa versa, and from L4 to H2.
Transfer Operation
H2 to H4
When the touch select 2–4 SW in the integration control and panel is turned ON, a signal is input into TERMINAL (A) 8 of the
4WD control ECU.
The 4WD control ECU is activated by this, and the current flows from the 4WD control ECU TERMINAL (B) 2 to transfer shift
actuator TERMINAL 2 to motor to TERMINAL 1 to 4WD control ECU TERMINAL (B) 1 to GROUND, and the transfer shifts to
4WD (H4 position.)
When the system shifts to 4WD, the detection SW (Transfer 4WD position) is turned ON, and the current flows from 4WD
control ECU TERMINAL (A) 2 to ADD actuator TERMINAL 5 to motor to TERMINAL 1 to 4WD control ECU TERMINAL (A) 1
to GROUND, and the ADD actuator is activated, and the ADD is connected. When the ADD is connected, the detection SW
(ADD position SW) is turned ON, and the 4HI Indicator light comes ON.
H4 to H2
When the touch select 2–4 SW in the integration control and panel is turned OFF, a signal is input into TERMINAL (A) 8 of
the 4WD control ECU.
The 4WD control ECU is activated by this, and the current flows from the 4WD control ECU TERMINAL (B) 1 to transfer shift
actuator TERMINAL 1 to motor to TERMINAL 2 to 4WD control ECU TERMINAL (B) 2 to GROUND, and the transfer shifts to
2WD (H2 position.)
When the system shifts to 2WD, the detection SW (Transfer 4WD position) is turned OFF, and the current flows from 4WD
control ECU TERMINAL (A) 1 to ADD actuator TERMINAL 1 to motor to TERMINAL 5 to 4WD control ECU TERMINAL (A) 2
to GROUND, and the ADD actuator is activated, and the ADD is disconnected. When the ADD is disconnected, the
detection SW (ADD position SW) is turned OFF, and the 4HI indicator Light turns OFF.
H4 to L4
When the touch select high–low SW in the integration control and panel is turned ON, a signal is input into TERMINAL (A) 15
of the 4WD control ECU.
The 4WD control ECU is activated by this, and the current flows from the 4WD control ECU TERMINAL (B) 2 to transfer shift
actuator TERMINAL 2 to motor to TERMINAL 1 to 4WD control ECU TERMINAL (B) 1 to GROUND, and the transfer shifts to
4WD LO position (L4 position.)
The 4HI Indicator is turned OFF and the 4LO indicator is turned ON.
L4 to H4
When the touch select high–low SW in the integration control and panel is turned OFF, a signal is input into TERMINAL (A)
15 of the 4WD control ECU.
The 4WD control ECU is activated by this, and the current flows from the 4WD control ECU TERMINAL (B) 1 to transfer shift
actuator TERMINAL 1 to motor to TERMINAL 2 to 4WD control ECU TERMINAL (B) 2 to GROUND, and the transfer shifts to
4WD HI position (H4 Position.)
The 4HI indicator is turned ON and the 4LO indicator is turned OFF.
The shift is not completed even though 3 seconds have elapsed after transfer operation.
∗ The vehicle speed is above approximately 100 km/h (63 mph) when shifting from H2 to H4.
∗ The vehicle speed is below approximately 5 km/h (3 mph) or the A/T Shift Lever is in a position other than N position,
when shifting from H4 to L4 or visa versa, and from L4 to H2.
L4 to H2
When the touch select 2–4 SW in the integration control and panel is turned OFF, a signal is input into TERMINAL (A) 8 of
the 4WD control ECU.
The 4WD control ECU is activated by this, and the current flows from the 4WD control ECU TERMINAL (B) 1 to transfer shift
actuator TERMINAL 1 to motor to TERMINAL 2 to 4WD control ECU TERMINAL (B) 2 to GROUND, and the detection SW
(Transfer L4 position) is turned OFF.
Furthermore, the motor rotates to shift the transfer to 2WD (H2 position.)
When the system shifts to 2WD, the detection SW (Transfer 4WD position) is turned OFF, and the current flows from 4WD
control ECU TERMINAL (A) 1 to ADD actuator TERMINAL 1 to motor to TERMINAL 5 to 4WD control ECU TERMINAL (A) 2
to GROUND, and the ADD actuator is activated, and the ADD is disconnected. When the ADD is disconnected, the
detection SW (ADD position SW) is turned OFF, and the 4LO indicator light turns OFF.

459

TOYOTA TUNDRA (EM00Q0U)

4WD (Double Cab)

H2 to L4
When the touch select 2–4 SW in the integration control and panel is turned ON, and the touch select high–low SW is turned
ON, a signal is input into TERMINAL (A) 8 of the 4WD control ECU.
The 4WD control ECU is activated by this, and the current flows from the 4WD control ECU TERMINAL (B) 2 to transfer shift
actuator TERMINAL 2 to motor to TERMINAL 1 to 4WD control ECU TERMINAL (B) 1 to GROUND, and the transfer shifts to
4WD (H4 position.)
When the system shifts to 4WD, the detection SW (Transfer 4WD position) is turned ON, and the current flows from 4WD
control ECU TERMINAL (A) 2 to ADD actuator TERMINAL 5 to motor to TERMINAL 1 to 4WD control ECU TERMINAL (A) 1
to GROUND, and the ADD actuator is activated, and the ADD is connected. Then a signal is input into TERMINAL (A) 15 of
the 4WD control ECU and the 4WD control ECU is activated by this, so the current flows from the 4WD control ECU
TERMINAL (B) 2 to transfer shift actuator TERMINAL 2 to motor to TERMINAL 1 to 4WD control ECU TERMINAL (B) 1 to
GROUND. The transfer shifts to 4WD LO position (L4 position), and the 4LO indicator light comes ON.

: Parts Location
Code See Page Code See Page Code See Page
A5 70 F21 B 73 J55 A 74
A9 70 I24 A 73 J56 B 74
C11 A 72 I25 B 73 J58 74
C12 B 72 J28 A 74 J64 74
D3 70 J29 B 74 P1 71
D4 70 J45 74 S29 A 71
E5 C 73 J49 A 74 T3 71
F20 A 73 J50 B 74

: Junction Block and Wire Harness Connector

Code See Page Junction Block and Wire Harness (Connector Location)
1D
1F 49 Cowl Wire and Driver Side J/B (Lower Finish Panel)
1H
4B
54 Cowl Wire and Sub J/B No.4 (Upper the Accelerator Pedal)
4D

: Connector Joining Wire Harness and Wire Harness

Code See Page Joining Wire Harness and Wire Harness (Connector Location)
EC1 90 Engine No.2 Wire and Engine Wire (Near the Starter)
ED1 90 Engine No.2 Wire and Differential Wire (Near the Transmission)
IE1
93 Engine Wire and Cowl Wire (Right Side of Instrument Panel)
IE4
IJ4 93 Engine Room Main Wire and Cowl Wire (Cowl Side Panel RH)

: Ground Points

Code See Page Ground Points Location

IN 92 Right Kick Panel
IO 92 Left Kick Panel

460

TOYOTA TUNDRA (EM00Q0U)