Toyota Sequoia (2005). Manual - part 528

DI3IS–11

I27730

Instrument Panel J/B

Passenger Door ECU
(Power Window Switch)

Combination Meter

Sliding Roof ECU

DLC3

Body ECU
(Located behind
the instrument panel)

Driver Door ECU
(Power Window
Master Switch)

Back Door ECU
(Located inside the back door trim board)

Automatic Light Control Sensor

Memory Seat ECU
& Switch

Airbag
Sensor
Assy

Power Window
Motor Front RH

 Limit Switch

 Pulse Switch

Power Window
Motor Front LH

 Limit Switch

 Pulse Switch

A/C ECU
(Integration Control and Panel)

–

DIAGNOSTICS

MULTIPLEX COMMUNICATION SYSTEM

DI–1907

2101

PARTS LOCATION

DIDFB–01

DI–1908

–

DIAGNOSTICS

MULTIPLEX COMMUNICATION SYSTEM

2102

CIRCUIT INSPECTION

DTC

B1211

Driver door ECU communication stop

CIRCUIT DESCRIPTION

This DTC is indicated when communication fails between the driver door ECU and body ECU.

DTC No.

DTC Detecting Condition

Trouble Area

B1211

No communication from driver door ECU for more than 10

Driver door ECU

Wi

h

B1211

No communication from driver door ECU for more than 10

seconds.

Wire harness

Body ECU

I28467

F18
Front Passenger Door ECU

D22
Driver Door ECU

Body ECU

J/C

I18
Ignition Switch

Instrument Panel J/B

Sub J/B No. 3

F10
FL Block

Sub J/B No. 3

Instrument Panel J/B

Engine Room R/B

J8
J/C

Battery

IE

ECU–B

Short Pin

ECU–IG

AM1

PWR No. 1

J/C

B7

IB1

II2

J6

J7

J37

J38

IB1

IB1

IB1

3C

3A

1F

1C

1L

1E

1J

2D

2C

1C

1F

3C

3A

ALT

IG1

AM1

IB1

MPX1

MPX2

GND

SIG

CPUB

BDR

MPX2

MPX1

W–L

W–R

L–W

G–B

W–B

B–R

W–L

G–B

G–B

W–B

B–R

W–R

W–L

B–Y

B–R

B–R

W–L

L–W

W–R

W

W–R

W–R

B

B

D

A

F

A

A

4

8

9

11

22

23

25

1

3

13

20

13

8

2

1

8

8

4

4

1

1

6

1

2

4

8

5

1

1

2

3

1

8

21

–

DIAGNOSTICS

MULTIPLEX COMMUNICATION SYSTEM

DI–1909

2103

WIRING DIAGRAM

DI–1910

–

DIAGNOSTICS

MULTIPLEX COMMUNICATION SYSTEM

2104

INSPECTION PROCEDURE

1

Check driver door ECU.

CHECK:
Check if the driver door window glass auto up function operates normally through the power window master
switch.
HINT:
With this inspection, the driver door ECU CPU can be diagnosed if it works normally or not.
OK:

Driver door side power window auto up function operates normally.

NG

Go to power source circuit (See page 

DI–1788

).

OK

2

Check wire harness and connector (Driver door ECU – body ECU and driver door
ECU – passenger door ECU).

PREPARATION:
Disconnect connector ”B7” of the body ECU, ”D22” of the driver door ECU and ”F18” the passenger door
ECU.
CHECK:
Measure the resistance according to the values in the table below.
OK:

Symbols (Tester connection)

Condition

Specified condition

MPX1 (B7–22) – MPX2 (D22–8)

Always

Below 1 

Ω

MPX1 (D22–20) – MPX2 (F18–11)

Always

Below 1 

Ω

MPX1 (B7–22) – Body ground

Always

10 k

Ω 

or higher

MPX1 (D22–20) – Body ground

Always

10 k

Ω 

or higher

NG

Repair or replace wire harness.

OK

Replace the driver door ECU.

If the problem reoccurs even after replacement, replace the body ECU.