Toyota Sequoia (2005). Manual - part 363

–

DIAGNOSTICS

SUPPLEMENTAL RESTRAINT SYSTEM

DI–1247

1441

DTC

B1662/45 SRS Warning Light Circuit Malfunction

CIRCUIT DESCRIPTION

The SRS warning light circuit consists of the airbag sensor assembly and the combination meter.
When the airbag sensor assembly detects a malfunction in the SRS airbag system, the SRS warning light
comes on to inform the driver.
It also comes on when the power voltage drops, and automatically goes off in approximately 10 seconds
after the power voltage returns to normal (DTC is not stored).
The SRS warning light comes on for 6 seconds after the ignition switch is turned to the ON position and goes
off if the system is normal.
When an open circuit is detected, such as when the connector between the combination meter and the air-
bag sensor assembly is disconnected, the SRS warning light remains on even when approximately 6 se-
conds elapsed after the ignition switch is turned to the ON position.
DTC B1662/45 is recorded when a malfunction is detected in the SRS warning light circuit.

DTC No.

DTC Detecting Condition

Trouble Area

B1662/45

The airbag sensor assembly receives an open circuit sig-

nal or a short circuit to ground signal in the SRS warning

light circuit for 2 seconds.

SRS warning light malfunction

Airbag sensor assembly malfunction

Combination meter (SRS warning light)

Airbag sensor assembly

Cowl wire

HINT:
When DTC B1662/45 and B1000/31 are output simultaneously, perform the troubleshooting for DTC
B1662/45 first.

DIDH3–01

H23996

LA

A20

14

AB

R

I18
Ignition SW

Combination Meter

Battery

IG2

A20

21

E1

A20

25

E2

A20

26

B

W–B

W–B

B–R

IG2

AM2

6

5

W–R

SRS

B–Y

C5

29

C6

12

C6

24

1D

4

1A

5

1A

3

IGN1

1D

6

1F

9

10

1A

6

1A

8

Instrument Panel J/B

Engine Room J/B

1H

11

1J

7

2C

1

2D

1

AM2

BR

W–B

W–B

J8
J/C

A

A

4

5

B

B

B–O

IE

Airbag Sensor
Assembly

1C

2

Instrument Panel J/B

F10
Fusible Link Block

1C

3

D6
DLC3

11

4B

10

4A

20

4A

10

B–Y

B–Y

1F

W–R

Sub J/B No. 4

DI–1248

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DIAGNOSTICS

SUPPLEMENTAL RESTRAINT SYSTEM

1442

WIRING DIAGRAM

–

DIAGNOSTICS

SUPPLEMENTAL RESTRAINT SYSTEM

DI–1249

1443

INSPECTION PROCEDURE

1

Check battery.

CHECK:
Measure the voltage of the battery.
OK:

Voltage: 11 to 14 V

NG

Replace battery.

OK

2

Check connection of connectors.

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.

CHECK:
Check that the connectors are properly connected to the airbag sensor assembly and combination meter.
OK:

The connectors are connected securely.

NG

Connect connectors, then go to step 1.

OK

3

Check combination meter.

PREPARATION:
(a)

Disconnect the connectors from the airbag sensor assembly.

(b)

Connect the negative (–) terminal cable to the battery, and wait for at least 2 seconds.

CHECK:
Turn the ignition switch to the ON position, check the operation of the SRS warning light.
OK:

The SRS warning light comes on (goes off 6 seconds after the ignition switch is turned to the
ON position).

NG

Go to combination meter system
(see page 

DI–1610

).

OK

H22564

H23040

I27704

H23986

A

Cowl Wire

Combination
Meter

C5

A20

Airbag
Sensor
Assembly

B

C

D

C5–29

LA

DI–1250

–

DIAGNOSTICS

SUPPLEMENTAL RESTRAINT SYSTEM

1444

4

Check cowl wire (airbag sensor assembly – combination meter).

PREPARATION:
Disconnect the connector from the combination meter.
CHECK:
Measure the resistance according to the value(s) in the table
below.
OK:

Tester Connection

Condition

Specified Condition

A20–14 (LA) – C5–29

Always

Below 1 

Ω

A20–14 (LA) – 

Body ground

Always

1 M

Ω

 or higher

NG

Repair or replace cowl wire.

OK

Replace airbag sensor assembly (see page 

RS–82

).