Lexus RX300 (MCU15). Service manual - part 292

AB0119
H01298

H01299

(–)

(+)

ON

Airbag Sensor Assembly

IG1

IG2

DI–400

–

DIAGNOSTICS

SUPPLEMENTAL RESTRAINT SYSTEM

LEXUS RX300   (RM785E)

DTC

B1100/31

Airbag Sensor Assembly Malfunction

CIRCUIT DESCRIPTION

The airbag sensor assembly consists of a airbag sensor, safing sensor, drive circuit, diagnosis circuit and
ignition control, etc. 
It receives signals from the airbag sensor, judges whether or not the SRS must be activated, and detects
diagnosis system malfunction. 
DTC B1100/31 is recorded when occurrence of a malfunction in the airbag sensor assembly is detected.

DTC No.

DTC Detecting Condition

Trouble Area

B1100/31

S Airbag sensor assembly malfunction

S Airbag sensor assembly

INSPECTION PROCEDURE

HINT:
When a malfunction code other than code B1100/31 is displayed at the same time, first repair the malfunction
indicated by the malfunction code other than code B1100/31.

1

Prepare for inspection (See step 1 on page DI–431).

2

Check voltage at IG1 and IG2 of airbag sensor assembly.

CHECK:
(a)

Turn the ignition switch to ON.

(b)

Measure the voltage between body ground and each of
terminals IG1 and IG2 of the airbag sensor assembly con-
nector.

OK:

Voltage: 10 – 14 V

NG

Check that an abnormality occurs on the battery
and charging system.

OK

DI6PR–01

AB0119

FI1394

H10600

H10635

ON

DTC B1100/31

DLC3

Tc

CG

–

DIAGNOSTICS

SUPPLEMENTAL RESTRAINT SYSTEM

DI–401

LEXUS RX300   (RM785E)

3

Is DTC B1100/31 output again?

PREPARATION:
Clear the DTC (See step 5 on page DI–305).
CHECK:
(a)

Turn the ignition switch to LOCK, and wait at least for 20
seconds.

(b)

Turn the ignition switch to ON, and wait at least for 20 se-
conds.

(c)

Repeat operation in step (a) and (b) at least 5 times.

(d)

Check the DTC (See page DI–305).

HINT:
Codes other than code B1100/31 may be output at this time, but
they are not relevant to this check.

NO

Using simulation method, reproduce malfunc-
tion symptoms (See page IN–22).

YES

Replace airbag sensor assembly.

H01450

Side Airbag Sensor Assembly (RH)

Airbag Sensor Assembly

GR

LG

L–Y

P

ESR

FSR

SSR+

VUPR

4

3

2

1

A29

7

9

10

12

ESR

FSR

SSR+

VUPR

A29

A29

A29

DI–402

–

DIAGNOSTICS

SUPPLEMENTAL RESTRAINT SYSTEM

LEXUS RX300   (RM785E)

DTC

B1140/32

Side Airbag Sensor Assembly (RH) 
Malfunction

CIRCUIT DESCRIPTION

The side airbag sensor assembly (RH) consists of the safing sensor, diagnosis circuit and lateral decelera-
tion sensor, etc. 
It receives signals from the lateral deceleration sensor, judges whether or not the SRS must be activated,
and detects diagnosis system malfunction. 
DTC B1140/32 is recorded when occurrence of a malfunction in the side airbag sensor assembly (RH) is
detected.

DTC No.

DTC Detecting Condition

Trouble Area

B1140/32

S Side airbag sensor assembly (RH) malfunction

S Side airbag sensor assembly (RH)

S Wire harness

S Airbag sensor assembly

WIRING DIAGRAM

DI6PS–04

H09528

AB0119
H10600

H12032

ON

CG

Tc

DTC B1140/32

DLC3

–

DIAGNOSTICS

SUPPLEMENTAL RESTRAINT SYSTEM

DI–403

LEXUS RX300   (RM785E)

INSPECTION PROCEDURE

1

Is DTC B1140/32 out put?

CHECK:
(a)

Turn the ignition switch to ON, and wait at least for 20 se-
conds.

(b)

Clear the DTC stored in memory (See page DI–305).

(c)

Turn the ignition switch to LOCK, and wait at least for 20
seconds.

(d)

Turn the ignition switch to ON, and wait at least for 20 se-
conds.

(e)

Check the DTC (See page DI–305).

HINT:
Codes other than code B1140/32 may be output at this time, but
they are not relevant to this check.

YES

The malfunctioning part can now be considered
normal. To make sure of this, use the simulation
method to check.

NO

2

Is connector of side airbag sensor assembly (RH) properly connected?

3

Prepare for inspection (See step 1 on DI–431).