Toyota Sequoia (2005). Manual - part 384

C84211

H24024

H24005

Occupant
Classification
ECU

Airbag
Sensor
Assembly

A

FSR+

FSR–

B

C

D

E

F

BL1

Seat Wire No. 1

Floor Wire

–

DIAGNOSTICS

SUPPLEMENTAL RESTRAINT SYSTEM

DI–1331

1525

16

Check seat wire No. 1 (short to ground).

PREPARATION:
Disconnect the seat wire No. 1 connector from the floor wire.
CHECK:
Measure the resistance according to the value(s) in the table
below.
OK:

Tester Connection

Condition

Specified Condition

BL1–3 (FSR+) – 

Body ground

Always

1 M

Ω

 or higher

BL1–5 (FSR–) – 

Body ground

Always

1 M

Ω

 or higher

NG

Repair or replace seat wire No. 1.

OK

Repair or replace floor wire.

DI–1332

–

DIAGNOSTICS

SUPPLEMENTAL RESTRAINT SYSTEM

1526

DTC

B1793

Occupant Classification Sensor Power 
Supply Circuit Malfunction

CIRCUIT DESCRIPTION

The occupant classification sensor power supply circuit consists of the occupant classification ECU and the
occupant classification sensors.
DTC B1793 is recorded when a malfunction is detected in the occupant classification sensor power supply
circuit.

DTC No.

DTC Detecting Condition

Trouble Area

B1793

The occupant classification ECU receives a line short

circuit signal, an open circuit signal, a short circuit to

ground signal or a short circuit to B+ signal in the .

Occupant classification ECU malfunction

Front seat assembly RH (Occupant classification sensors)

Occupant classification ECU

Seat wire No. 1

HINT:
When DTC B1650/32 is detected as a result of troubleshooting for the supplemental restraint system, check
the DTCs stored in the occupant classification ECU. When DTC B1793 is output, perform troubleshooting
for the DTC.

DIDHE–01

H24041

Occupant
Classification ECU

O7

SVC1

11

1

O8
Occupant Classification
Sensor Front LH

V

O7

SVC2

12

O7

SVC3

5

O7

SVC4

6

P

Y–B

Y

1

1

1

O9
Occupant Classification
Sensor Front RH

O10
Occupant Classification
Sensor Rear LH

O11
Occupant Classification
Sensor Rear RH

SVC1

SVC2

SVC3

SVC4

–

DIAGNOSTICS

SUPPLEMENTAL RESTRAINT SYSTEM

DI–1333

1527

WIRING DIAGRAM

DI–1334

–

DIAGNOSTICS

SUPPLEMENTAL RESTRAINT SYSTEM

1528

INSPECTION PROCEDURE

HINT:

If troubleshooting (wire harness inspection) is difficult to perform, remove the passenger seat installa-
tion bolts to see the under surface of seat cushion.

In the above case, hold the seat so that it does not fall down. Holding the seat for a long period of time
may cause a problem, such as seat rail deformation. Hold the seat only as necessary.

1

Check DTC.

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.

(e)

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

DI–1147

).

OK:

DTC B1793 is not output.

HINT:
Codes other than DTC B1793 may be output at this time, but they are not related to this check.

NG

Go to step 2.

OK

From the results of the above inspection, the malfunctioning part can now be considered normal.
To make sure of this, use the simulation method to check (see page 

DI–1137

).