Lexus ES300 (1997 year). Service manual — part 394

R15195

Airbag Sensor
Assembly

1

2

2

P+

P–

P Squib

Y–R

Y–G

3

–

DIAGNOSTICS

SUPPLEMENTAL RESTRAINT SYSTEM

DI–353

505

1997 LEXUS ES300 (RM511U)

DTC

53

Short in P Squib Circuit

CIRCUIT DESCRIPTION

The P squib circuit consists of the airbag sensor assembly and front passenger airbag assembly.
It causes the airbag to deploy when the airbag deployment conditions are satisfied.
For details of the function of each components, see OPERATION on page

RS–2

.

DTC 53 is recorded when a short is detected in the P squib circuit.

DTC No.

DTC Detecting Condition

Trouble Area

53

Short circuit between P+ wire harness or P– wire harness

of squib

P squib malfunction

Airbag sensor assembly malfunction

Front passenger airbag assembly (P squib)

Airbag sensor assembly

Wire harness

WIRING DIAGRAM

INSPECTION PROCEDURE

1

Preparation. (See step ” 1 ” on page

DI–359

)

DI0B5–01

R05898

R14287

H00045

Airbag Sensor
Assembly

Spiral
Cable

P Squib

D Squib

P–

P+

(–)

(+)

AB0118

R13006

AB0119

W01933

R05169

H00046

Airbag Sensor
Assembly

P Squib

D Squib

Spiral
Cable

ACC

ON

or

DLC1

E1

Tc

Code 53

DI–354

–

DIAGNOSTICS

SUPPLEMENTAL RESTRAINT SYSTEM

506

1997 LEXUS ES300 (RM511U)

2

Check P squib circuit.

PREPARATION:
Release airbag activation prevention mechanism on airbag
sensor assembly side of airbag squib connector
(See page

DI–324

).

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

Resistance: 1M

Ω

or Higher

NG

Repair or replace harness or connector be-
tween airbag sensor assembly and front pas-
senger airbag assembly.

OK

3

Check airbag sensor assembly.

PREPARATION:
(a)

Connect connector to airbag sensor assembly.

(b)

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

CHECK:
(a)

Turn ignition switch to ACC or ON and wait at least 20 se-
conds.

(b)

Clear malfunction code stored in memory
(See page

DI–324

).

(c)

Turn ignition switch to LOCK, and wait at least 20 se-
conds.

(d)

Turn ignition switch to ACC or ON, and wait at least 20 se-
conds.

(e)

Using SST, connect terminal Tc and E1 of DLC1.
SST 09843–18020

(f)

Check DTC.

OK:

DTC 53 is not output.

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

R05909

AB0118

R13006

AB0119

R05169

H00047

Airbag Sensor
Assembly

P Squib

D Squib

Spiral
Cable

ACC

ON

or

DLC1

E1

Tc

Code 53

–

DIAGNOSTICS

SUPPLEMENTAL RESTRAINT SYSTEM

DI–355

507

1997 LEXUS ES300 (RM511U)

NG

Replace airbag sensor assembly.

OK

4

Check P squib.

PREPARATION:
(a)

Turn ignition switch to LOCK.

(b)

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

(c)

Connect front passenger airbag assembly connector.

(d)

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

CHECK:
(a)

Turn igniton switch to LOCK, and wait at least 20 se-
conds.

(b)

Turn ignition switch to ACC or ON and wait at least 20 se-
conds.

(c)

Clear malfunction code stored in memory
(See page

DI–324

).

(d)

Turn ignition switch to LOCK, and wait at least 20 se-
conds.

(e)

Turn ignition switch to ACC or ON, and wait at least 20 se-
conds.

(f)

Using SST, connect terminal Tc and E1 of DLC1.
SST 09843–18020

(g)

Check DTC.

OK:

DTC 53 is not output.

HINT:
Codes other than code 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.

R15195

Airbag Sensor
Assembly

1

2

2

P+

P–

P Squib

3

Y–R

Y–G

DI–356

–

DIAGNOSTICS

SUPPLEMENTAL RESTRAINT SYSTEM

508

1997 LEXUS ES300 (RM511U)

DTC

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 airbag to deploy when the airbag deployment conditions are satisfied.
For details of the function of each components, see OPERATION on page

RS–2

.

DTC 54 is recorded when an open is detected in the P squib circuit.

DTC No.

DTC Detecting Condition

Trouble Area

54

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

squib

P squib malfunction

Airbag sensor assembly malfunction

Front passenger airbag assembly (P squib)

Airbag sensor assembly

Wire harness

WIRING DIAGRAM

INSPECTION PROCEDURE

1

Preparation. (See step ” 1 ” on page

DI–359

)

DI0B6–01