Toyota Sequoia (2005). Manual - part 539

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DIAGNOSTICS

MULTIPLEX COMMUNICATION SYSTEM

DI–1951

2145

INSPECTION PROCEDURE

1

Check sliding roof ECU.

CHECK:
Check that the operation of the sliding roof function is normal.
HINT:
The operating condition of the sliding roof ECU CPU can be diagnosed with this check.
OK:

The sliding roof operates normally.

NG

Go to power source circuit (See page 

DI–1668

).

OK

2

Check wire harness and connector (Sliding roof control ECU – body ECU).

PREPARATION:
Disconnect connector ”B7” of the body ECU and connector ”S19” of the sliding roof ECU.
CHECK:
Measure the resistance according to the values in the table below.
OK:

Tester connection (Symbols)

Condition

Specified condition

S19–2 (MPX1) – B7–20 (MPX3)

Always

Below 1 

Ω

S19–2 (MPX1) – Body ground

Always

10 k

Ω 

or higher

NG

Repair or replace wire harness.

OK

Replace the sliding roof ECU.

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

DI–1952

–

DIAGNOSTICS

MULTIPLEX COMMUNICATION SYSTEM

2146

DTC

B1287

Back door ECU communication stop

CIRCUIT DESCRIPTION

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

DTC No.

DTC Detecting Condition

Trouble Area

B1287

No communication from back door ECU for more than 10 se-

conds.

Back door ECU

Wire harness

Body ECU

DIDFM–01

I28473

Combination Meter

F18
Front Passenger
Door ECU

Back Door ECU

Sub J/B No. 3

I18
Ignition SW

Instrument Panel J/B

F10
Fusible Link Block

Engine Room J/B

Instrument Panel J/B

Sub J/B No. 3

Battery

BJ

J19
J/C

J22
J/C

J37
J/C

J/C

J/C

J33

J34

J33

J34

C5

B11

BF1

BD2

II2

B11

B11

B11

BF1

BD2

BD2

BF1

IN1

AM1

ECU–IG

1F

1L

1G

1C

1

4

6

1

2

1C

15

4

1

2

PWR No. 5

ALT

5

8

4

3C

3A

8

8

A

A

G

A

B

H

IG1

AM1

1

2

6

7

31

2

1

6

4

2

5

11

11

14

8

B

B

B

B

B

20 (*1)

LG–R

B–R

LG–R

LG–R

LG–R

B–R

B–R

B–R

B–R

B–R

B–Y

W–L

W

B

B

L–W

L–W

L–W

L–W

W–R

W–R

W–R

W–R

W–R

W–R

W–B

W–B

W–B

W–B

A

2

12

B

B

3

5

B11

B11

10

12

1

1

2

3A

3C

BD2

BF1

BF1

BD1

IN1

BF1

BD1

IC4

2

3

8

1

1J

1E

2C

2D

ECU–B

Short Pin

2

3

10

MPX1

SIG

BDR

GND

MPX2

BECU

MPX1

*1: w/ Driving Position Memory
*2: w/o Driving Position Memory

10 (*2)

–

DIAGNOSTICS

MULTIPLEX COMMUNICATION SYSTEM

DI–1953

2147

WIRING DIAGRAM

DI–1954

–

DIAGNOSTICS

MULTIPLEX COMMUNICATION SYSTEM

2148

INSPECTION PROCEDURE

1

Check back door ECU.

CHECK:
Check that the operation of the rear wiper motor function is normal.
HINT:
With this inspection, the back door ECU CPU can be diagnosed if it works normally or not.
OK:

Rear wiper motor operates normally.

NG

Replace the back door ECU.

OK

2

Check wire harness and connector (Back door ECU – combination meter, back
door ECU – passenger door ECU).

PREPARATION:
Disconnect connector ”F18” of the passenger door ECU, connector ”B11” of the back door ECU and connec-
tor ”C5” of the combination meter ECU.
CHECK:
Measure the resistance according to the values in the table below.
OK:

Tester connection (Symbols)

Condition

Specified condition

B11–2 (MPX1) – C5–31

Always

Below 1 

Ω

B11–1 (MPX2) – F18–10 (*1)

Always

Below 1 

Ω

B11–1 (MPX2) – F18–20 (*2)

Always

Below 1 

Ω

B11–1 (MPX2) – Body ground

Always

10 k

Ω 

or higher

B11–2 (MPX1) – Body ground

Always

10 k

Ω 

or higher

*1: w/ Driving Position Memory
*2: w/o Driving Position Memory

NG

Repair or replace wire harness.

OK

Replace the back door ECU.

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