Toyota Sequoia (2005). Manual — part 386

–

DIAGNOSTICS

SUPPLEMENTAL RESTRAINT SYSTEM

DI–1339

1533

8

Replace occupant classification ECU.

(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)

Replace the occupant classification ECU (see page

RS–111

).

HINT:
Perform the inspection using parts from a normal vehicle if possible.

NEXT

9

Perform zero point calibration.

(a)

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

(b)

Connect the hand–held tester to the DLC3.

(c)

Turn the ignition switch to the ON position.

(d)

Using the hand–held tester, perform ”Zero point calibration” (see page

DI–1128

).

OK:

The ”COMPLETED” is displayed.

NG

Go to step 12.

OK

10

Perform sensitivity check.

Using the hand–held tester, perform ”Sensitivity check” (see page

DI–1128

).

OK:

Standard value: 27 to 33 kg (59.52 to 72.75 lb)

NG

Go to step 12.

OK

DI–1340

–

DIAGNOSTICS

SUPPLEMENTAL RESTRAINT SYSTEM

1534

11

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 12.

OK

END

–

DIAGNOSTICS

SUPPLEMENTAL RESTRAINT SYSTEM

DI–1341

1535

12

Replace front seat assembly RH.

(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)

Replace the front seat assembly RH (see page

BO–112

,

BO–126

).

NEXT

13

Perform zero point calibration.

(a)

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

(b)

Connect the hand–held tester to the DLC3.

(c)

Turn the ignition switch to the ON position.

(d)

Using the hand–held tester, perform ”Zero point calibration” (see page

DI–1128

).

OK:

The ”COMPLETED” is displayed.

NEXT

14

Perform sensitivity check.

Using the hand–held tester, perform ”Sensitivity check” (see page

DI–1128

).

OK:

Standard value: 27 to 33 kg (59.52 to 72.75 lb)

NEXT

END

DI–1342

–

DIAGNOSTICS

SUPPLEMENTAL RESTRAINT SYSTEM

1536

DTC

B1794

Occupant Classification ECU Battery
Positive Line Open

CIRCUIT DESCRIPTION

This circuit consists of the occupant classification ECU and the power source circuit (battery, fuse, wire har-
ness).
DTC B1794 is recorded when a malfunction is detected in the occupant classification ECU or the power
source circuit.
HINT:
When DTC B1794 is output after switching the ignition switch LOCK–ON–LOCK 50 times in a row when a
malfunction occurs in the power source circuit for the occupant classification system, the DTC is output again
when a malfunction is detected even once after being cleared, unless the normal system code is input.

DTC No.

DTC Detecting Condition

Trouble Area

B1794

The ignition switch is turned from LOCK to ON, hold for 10

seconds or more, and back to LOCK again 50 times in a

row when a malfunction occurs in the power source circuit

for the occupant classification system.

Occupant classification ECU malfunction

Battery

ECU–B Fuse

Floor wire

Seat wire No. 1

Occupant classification ECU

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 B1794 is output, perform troubleshooting
for the DTC.

DIDHF–01