Lexus RX300 (MCU15). Service manual - part 276

R14286
H02142

H02251

P Squib

Airbag 
Sensor 
Assembly

P +

P–

(–)

(+)

DI–336

–

DIAGNOSTICS

SUPPLEMENTAL RESTRAINT SYSTEM

LEXUS RX300   (RM785E)

INSPECTION PROCEDURE

1

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

2

Check P squib circuit.

PREPARATION:
Release the airbag activation prevention mechanism of the
connector (on the airbag sensor assembly side) between the
front passenger airbag assembly and the airbag sensor assem-
bly (See page DI–305).
CHECK:
For the connector (on the front passenger airbag assembly
side) between the front passenger airbag assembly and the air-
bag sensor assembly, measure the resistance between P+ and
P–.
OK:

Resistance: 1 MΩ or Higher

NG

Repair or replace harness or connector be-
tween front passenger airbag assembly and air-
bag sensor assembly.

OK

H01023
AB0119

H01077

H10600

H10611

P Squib

Airbag
Sensor
Assembly

DTC B0105/53

DLC3

ON

→

 ←

Tc

CG

–

DIAGNOSTICS

SUPPLEMENTAL RESTRAINT SYSTEM

DI–337

LEXUS RX300   (RM785E)

3

Check airbag sensor assembly.

PREPARATION:
(a)

Connect the connector to the airbag sensor assembly.

(b)

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

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).

OK:

DTC B0105/53 is not output.

HINT:
Codes other than code B0105/53 may be output at this time, but
they are not relevant to this check.

NG

Replace airbag sensor assembly.

OK

H01024

AB0119

H01077

H10600

H10612

→ ←

ON

DTC B0105/53

DLC3

Airbag
Sensor
Assembly

P Squib

Tc

CG

DI–338

–

DIAGNOSTICS

SUPPLEMENTAL RESTRAINT SYSTEM

LEXUS RX300   (RM785E)

4

Check P squib.

PREPARATION:
(a)

Turn the ignition switch to LOCK.

(b)

Disconnect negative (–) terminal cable from the battery,
and wait at least for 90 seconds.

(c)

Connect the front passenger airbag assembly connector.

(d)

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

CHECK:
(a)

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

(b)

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

(c)

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

(d)

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

(e)

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

(f)

Check the DTC (See page DI–305).

OK:

DTC B0105/53 is not output.

HINT:
Codes other than code B0105/53 may be output at this time, but
they are not relevant to this check.

NG

Replace front passenger airbag assembly.

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.

R14286
H02142

H02251

P Squib

Airbag 
Sensor 
Assembly

P +

P–

(–)

(+)

–

DIAGNOSTICS

SUPPLEMENTAL RESTRAINT SYSTEM

DI–339

LEXUS RX300   (RM785E)

DTC

B0106/54

Open in P Squib Circuit

CIRCUIT DESCRIPTION

The P squib circuit consists of the airbag sensor assembly and front passenger airbag assembly. 
It causes the SRS to deploy when the SRS deployment conditions are satisfied. 
For details of the function of each component, see OPERATION on page RS–2. 
DTC B0106/54 is recorded when an open is detected in the P squib circuit.

DTC No.

DTC Detecting Condition

Trouble Area

B0106/54

S Open circuit in P+ wire harness or P– wire harness of

squib

S P squib malfunction

S Airbag sensor assembly malfunction

S Front passenger airbag assembly (P squib)

S Airbag sensor assembly

S Wire harness

WIRING DIAGRAM

See page DI–335.

INSPECTION PROCEDURE

1

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

2

Check P squib circuit.

CHECK:
For the connector (on the front passenger airbag assembly
side) between the front passenger airbag assembly and the air-
bag sensor assembly, measure the resistance between P+ and
P–.
OK:

Resistance: Below 1 Ω

NG

Repair or replace harness or connector be-
tween front passenger airbag assembly and air-
bag sensor assembly.

OK

DI6P8–01