Toyota Sequoia (2005). Manual - part 387

H23999

Occupant
Classification ECU

O6 +B

1

BL1

1

W–R

J49

O6

IG

7

O6

GND

3

W–R

C

J/C

I

J48

W–R

2

3D

1

3A

Sub J/B No. 3

W–R

W–R

W–R

W–B

W–B

BL1

6

BL1

2

B–O

B–O

J45

B

J/C

I

J44

B–O

2

4C

2

4D

Sub J/B No. 4

B–O

Instrument Panel J/B

17

1E

2

1C

IGN1

3

1C

2

1E

3

1J

7

1J

I18
Ignition SW

IG2

B–R

AM2

6

5

W–R

W–R

Engine Room J/B

8

2C

1

2D

ECU–B

Short Pin

1

2C

AM2

F10
FL Block

5

4

B

B

Battery

BK

–

DIAGNOSTICS

SUPPLEMENTAL RESTRAINT SYSTEM

DI–1343

1537

WIRING DIAGRAM

DI–1344

–

DIAGNOSTICS

SUPPLEMENTAL RESTRAINT SYSTEM

1538

INSPECTION PROCEDURE

1

Check battery.

CHECK:
Measure the voltage of the battery.
OK:

Voltage: 11 to 14 V

NG

Replace battery.

OK

2

Check fuse.

CHECK:
Check the ECU–B fuse.
OK:

Resistance: Below 1 

Ω

NG

Replace fuse.

OK

H23821

O6

+B

GND

Occupant Classification ECU:

IG

–

DIAGNOSTICS

SUPPLEMENTAL RESTRAINT SYSTEM

DI–1345

1539

3

Check seat wire No. 1 (source voltage).

PREPARATION:
(a)

Turn the ignition switch to the LOCK position.

(b)

Disconnect the negative (–) terminal cable from the bat-
tery, and wait for at least 90 seconds.

(c)

Disconnect the connector from the occupant classifica-
tion ECU.

(d)

Connect the negative (–) terminal cable to the battery.

CHECK:
(a)

Turn the ignition switch to the ON position.

(b)

Measure the voltage and resistance according to the val-
ue(s) in the table below.

OK:

Tester Connection

Condition

Specified Condition

O6–1 (+B) – Body ground

Ignition switch ON

10 to 14 V

O6–3 (GND) – 

Body ground

Always

Below 1 

Ω

O6–7 (IG) – Body ground

Ignition switch ON

10 to 14 V

NG

Repair or replace seat wire No. 1.

OK

DI–1346

–

DIAGNOSTICS

SUPPLEMENTAL RESTRAINT SYSTEM

1540

4

Check DTC.

PREPARATION:
(a)

Turn the ignition switch to the LOCK position.

(b)

Disconnect the negative (–) terminal cable from the battery, and wait for at least 90 seconds.

(c)

Connect the connector to the occupant classification ECU.

CHECK:
(a)

Turn the ignition switch to the ON position.

(b)

Clear the DTCs stored in memory (see page 

DI–1147

).

HINT:
First clear DTCs stored in the occupant classification ECU and then in the airbag sensor assembly.
(c)

Turn the ignition switch to the LOCK position.

(d)

Turn the ignition switch to the ON position, and wait for at least 10 seconds.

(e)

Using the hand–held tester, check the DTCs of the occupant classification ECU (see page 

DI–1147

).

OK:

DTC B1794 is not output.

HINT:
Codes other than DTC B1794 may be output at this time, but they are not related to this check.

NG

Go to step 5.

OK

From the results of the above inspection, the malfunctioning part can not be considered normal.
To make sure of this, use the simulation method to check (see page 

DI–1137

).