Toyota Sequoia (2005). Manual - part 389

–

DIAGNOSTICS

SUPPLEMENTAL RESTRAINT SYSTEM

DI–1351

1545

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–1352

–

DIAGNOSTICS

SUPPLEMENTAL RESTRAINT SYSTEM

1546

DTC

B1800/51 Short in D Squib Circuit

DTC

B1801/51 Open in D Squib Circuit

DTC

B1802/51 Short in D Squib Circuit (to Ground)

DTC

B1803/51 Short in D Squib Circuit (to B+)

CIRCUIT DESCRIPTION

The D squib circuit consists of the airbag sensor assembly, the spiral cable and the steering wheel pad.
The circuit instructs the SRS to deploy when deployment conditions are met.
These DTCs are recorded when a malfunction is detected in the D squib circuit.

DTC No.

DTC Detection Condition

Trouble Area

B1800/51

The airbag sensor assembly receives a line short circuit

signal 5 times in the D squib circuit during primary check.

Spiral cable malfunction

D squib malfunction

Airbag sensor assembly malfunction

Steering wheel pad (D squib)

Airbag sensor assembly

Spiral cable

Cowl wire

B1801/51

The airbag sensor assembly receives an open circuit sig-

nal in the D squib circuit for 2 seconds.

Spiral cable malfunction

D squib malfunction

Airbag sensor assembly malfunction

Steering wheel pad (D squib)

Airbag sensor assembly

Spiral cable

Cowl wire

B1802/51

The airbag sensor assembly receives a short circuit to

ground signal in the D squib circuit for 0.5 seconds.

Spiral cable malfunction

D squib malfunction

Airbag sensor assembly malfunction

Steering wheel pad (D squib)

Airbag sensor assembly

Spiral cable

Cowl wire

B1803/51

The airbag sensor assembly receive a short to B+ circuit

signal in the D squib circuit for 0.5 seconds.

Spiral cable malfunction

D squib malfunction

Airbag sensor assembly malfunction

Steering wheel pad (D squib)

Airbag sensor assembly

Spiral cable

Cowl wire

DIDHI–01

H01451

Airbag Sensor Assembly

A20

5

D+

Y–B

D Squib

A23
Spiral Cable

A20

6

D–

Y

1

2

–

DIAGNOSTICS

SUPPLEMENTAL RESTRAINT SYSTEM

DI–1353

1547

WIRING DIAGRAM

DI–1354

–

DIAGNOSTICS

SUPPLEMENTAL RESTRAINT SYSTEM

1548

INSPECTION PROCEDURE

CAUTION:
Be sure to perform the following procedures before troubleshooting to avoid unexpected airbag de-
ployment.
(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)

Disconnect the connectors from the airbag sensor assembly.

(d)

Disconnect the connectors from the steering wheel pad.

(e)

Disconnect the connectors from the front passenger airbag assembly.

(f)

w/ Side and curtain shield airbag:
Disconnect the connectors from the side airbag assembly LH and RH.

(g)

w/ Side and curtain shield airbag:
Disconnect the connectors from the curtain shield airbag assembly LH and RH.

(h)

Disconnect the connectors from the front seat outer belt LH and RH.

1

Check DTC.

CHECK:
Proceed to each step according to how to read DTC.

(1)

If using the hand–held tester (read the 5–digit of DTC):
Using the hand–held tester, check the DTCs (see page 

DI–1147

).

RESULT:

DTC B1800 is output.

A

DTC B1801 is output.

B

DTC B1802 is output.

C

DTC B1803 is output.

D

(2)

If not using the hand–held tester (read the 2–digit of DTC):
Check the DTCs (see page 

DI–1147

).

RESULT:

DTC 51 is output.

E

HINT:
Codes other than DTC B1800, B1801, B1802, B1803 and DTC 51 may be output at this time, but they are
not related to this check.

B

Go to step 4.

C

Go to step 5.

D

Go to step 6.

E

Go to step 7.

A