Toyota Sequoia (2005). Manual - part 388

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DIAGNOSTICS

SUPPLEMENTAL RESTRAINT SYSTEM

DI–1347

1541

5

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 is possible.

NEXT

6

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 the ”Zero point calibration” (see page 

DI–1128

).

OK:

The ”COMPLETED” is displayed.

NEXT

7

Perform sensitivity check.

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

DI–1128

).

OK:

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

NEXT

END

DI–1348

–

DIAGNOSTICS

SUPPLEMENTAL RESTRAINT SYSTEM

1542

DTC

B1795

Occupant Classification ECU Circuit 
Malfunction

CIRCUIT DESCRIPTION

DTC B1795 is recorded when a malfunction is detected in the occupant classification ECU.
Troubleshoot DTC B1771 first when the DTC B1771 and B1795 are output simultaneously.

DTC No.

DTC Detecting Condition

Trouble Area

B1795

Occupant classification ECU circuit malfunction

The occupant classification ECU receives a short circuit to

ground signal in the passenger side buckle switch circuit

for 2 seconds.

Occupant classification ECU malfunction

Occupant classification ECU

Front seat inner belt RH

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 B1795 is output, perform troubleshooting
for the DTC.

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, and wait for at least 10 seconds.

(b)

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

DI–1147

).

RESULT:

A: DTC B1795 is output.
B: DTC B1771 and B1795 are output.

HINT:
Codes other than DTC B1771 and B1795 may be output at this time, but they are not related to this check.

B

Go to DTC B1771 (see page 

DI–1251

).

A

DIDHG–01

–

DIAGNOSTICS

SUPPLEMENTAL RESTRAINT SYSTEM

DI–1349

1543

2

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

3

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

4

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–1350

–

DIAGNOSTICS

SUPPLEMENTAL RESTRAINT SYSTEM

1544

DTC

B1796

Sleep Operation Failure Of Occupant 
Classification ECU

CIRCUIT DESCRIPTION

During sleep mode, the occupant classification ECU reads the condition of each sensor while the ignition
switch is off.
In this mode, if occupant classification ECU detects an internal malfunction, DTC B1796 is output.

DTC No.

DTC Detecting Condition

Trouble Area

B1796

Occupant classification ECU malfunction

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 B1796 is output, perform troubleshooting
for the DTC.

INSPECTION PROCEDURE

1

Check DTC.

CHECK:
(a)

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

(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 B1796 is not output.

HINT:
Codes other than DTC B1796 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

).

DIDHH–01