Lexus RX300 (MCU15). Manual - part 298

H03354

H09507

H08351

Airbag 
Sensor 
Assembly

Front Airbag 
Sensor (RH)

(–)

+SR

–SR

Engine Room No. 2
Wire Harness

(+)

←

 →

DI–424

–

DIAGNOSTICS

SUPPLEMENTAL RESTRAINT SYSTEM

LEXUS RX300   (RM785E)

10

Check engine room No. 2 wire harness.

PREPARATION:
Disconnect the engine room No. 2 wire harness connector on
the airbag sensor assembly side.
CHECK:
For the connector (on the engine room No. 2 wire harness side)
between the airbag sensor assembly and the engine room No.
2 wire harness, measure the resistance between +SR and –SR.
OK:

Resistance: 1 MΩ or Higher

NG

Repair or replace engine room No. 2 wire har-
ness.

OK

Repair or replace harness or connector between airbag sensor assembly and engine room No.
2 wire harness.

H03352

H09507

H03360

H08350

Airbag 
Sensor 
Assembly

Front Airbag 
Sensor (RH)

(+)

+SR

(–)

–SR

Engine Room No. 2
Wire Harness

+SR

–SR

←

 →

–

DIAGNOSTICS

SUPPLEMENTAL RESTRAINT SYSTEM

DI–425

LEXUS RX300   (RM785E)

11

Check engine room No. 2 wire harness.

PREPARATION:
(a)

Disconnect the engine room No. 2 wire harness connec-
tor on the airbag sensor assembly side.

(b)

Using a service wire, connect +SR and –SR of the con-
nector (on the engine room No. 2 wire harness side) be-
tween the engine room No. 2 wire harness and the front
airbag sensor (RH).

CHECK:
For the connector (on the engine room No. 2 wire harness side)
between the airbag sensor assembly and the engine room No.
2 wire harness, measure the resistance between +SR and –SR.
OK:

Resistance: Below 1 Ω

NG

Repair or replace engine room No. 2 wire har-
ness.

OK

Repair or replace harness or connector between airbag sensor assembly and engine room No.
2 wire harness.

H05156

Airbag Sensor Assembly

Front Airbag Sensor (LH)

15

26

2

1

+SL

–SL

A28

S8

S8

A28

+SL

–SL

1

1

2

2

S̷

S̷

BR

W–R

Short Connector

W

B

DI–426

–

DIAGNOSTICS

SUPPLEMENTAL RESTRAINT SYSTEM

LEXUS RX300   (RM785E)

DTC

B1158/B1159/16

Front Airbag Sensor (LH) Malfunction

CIRCUIT DESCRIPTION

The front airbag sensor (LH) circuit consists of the airbag sensor assembly and front airbag sensor (LH).
For details of the function of each component, see OPERATION on page RS–2.
DTC B1158/B1159/16 is recorded when malfunction is detected in the front airbag sensor (LH) circuit.

DTC No.

DTC Detecting Condition

Trouble Area

B1158/B1159/16

S Front airbag sensor (LH) malfunction

S Front airbag sensor (LH)

S Airbag sensor assembly

S Wire harness

WIRING DIAGRAM

DI850–01

AB0119

H01370

H08065

H16264

Airbag
Sensor
Assembly

Front Airbag 
Sensor (LH)

(+)

+SL

(–)

–SL

Airbag Sensor Assembly

ON

H01370
H08399

H16265

Airbag
Sensor
Assembly

Front Airbag
Sensor (LH)

(+)

+SL

(–)

–SL

Airbag Sensor Assembly

–

DIAGNOSTICS

SUPPLEMENTAL RESTRAINT SYSTEM

DI–427

LEXUS RX300   (RM785E)

INSPECTION PROCEDURE

1

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

2

Check wire harness (to B+).

CHECK:
(a)

Turn the ignition switch to ON.

(b)

For the connector (on the airbag sensor assembly side)
between the front airbag sensor (LH) and the airbag sen-
sor assembly, measure the voltage between body ground
and each of +SL and –SL.

OK:

Voltage: Below 1 V

NG

Repair or replace harness or connector be-
tween front airbag sensor (LH) and airbag sen-
sor assembly.

OK

3

Check wire harness (to ground).

CHECK:
For the connector (on the airbag sensor assembly side) be-
tween the front airbag sensor (LH) and the airbag sensor as-
sembly, measure the resistance between body ground and
each of +SL and –SL.
OK:

Resistance: 1 MΩ or Higher

NG

Repair or replace harness or connector be-
tween front airbag sensor (LH) and airbag sen-
sor assembly.

OK