Lexus ES300 (1997 year). Manual — part 393

R05896

AB0118

R13006

AB0119

W02044

H00018

Airbag Sensor
Assembly

Spiral
Cable

P Squib

D Squib

ACC

ON

or

DLC1

E1

Tc

Code 14

–

DIAGNOSTICS

SUPPLEMENTAL RESTRAINT SYSTEM

DI–349

501

1997 LEXUS ES300 (RM511U)

NG

Replace airbag sensor assembly.

OK

4

Check D squib.

PREPARATION:
(a)

Turn ignition switch to LOCK.

(b)

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

(c)

Connect steering wheel pad connector.

(d)

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 terminals Tc and E1 of DLC 1.
SST 09843–18020

(f)

Check DTC.

OK:

DTC 14 is not output.

HINT:
Codes other than code 14 may be output at this time, but they
are not relevant to this check.

NG

Replace steering wheel pad.

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.

R05899

R14286

H00019

P Squib

D+

D–

(+)

(–)

Airbag Sensor
Assembly

Spiral
Cable

D Squib

R05904

R14286

H00058

D–

D+

(+)

(–)

P Squib

Airbag Senser
Assembly

Spiral
Cable

D Squib

DI–350

–

DIAGNOSTICS

SUPPLEMENTAL RESTRAINT SYSTEM

502

1997 LEXUS ES300 (RM511U)

5

Check spiral cable.

PREPARATION:
Disconnect connector between airbag sensor assembly and
spiral cable.
CHECK:
For the connector (on the spiral cable side) between the spiral
cable and steering wheel pad, measure the resistance between
D+ and D–.
OK:

Resistance: Below 1

Ω

NG

Repair or replace spiral cable.

OK

6

Check harness between airbag sensor assembly and spiral cable.

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

Resistance: Below 1

Ω

NG

Repair or replace harness or connector be-
tween airbag sensor assembly and spiral cable.

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.

AB0119

W02766

H00041

Airbag Sensor Assembly

ON

IG2

ACC

(+)

(–)

–

DIAGNOSTICS

SUPPLEMENTAL RESTRAINT SYSTEM

DI–351

503

1997 LEXUS ES300 (RM511U)

DTC

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 diagnosis
system malfunction.
DTC 31 is recorded when occurrence of a malfunction in the airbag sensor assembly is detected.

DTC No.

DTC Detecting Condition

Trouble Area

31

Airbag sensor assembly malfunction

Airbag sensor assembly

INSPECTION PROCEDURE

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

1

Preparation. (See step ” 1 ” on page

DI–359

)

2

Check voltage at IG2 and ACC of airbag sensor assembly

PREPARATION:
Turn ignition switch ON.
CHECK:
Measure voltage between terminals IG2 and ACC of airbag
sensor assembly and body ground.
OK:

Voltage: Below 16 V

NG

Check battery and charging system.
(See charging system section)

OK

DI0B4–01

AB0118

R13006

AB0119

FI1394

H00022

ACC

ON

or

DLC1

E1

Tc

Code 31

DI–352

–

DIAGNOSTICS

SUPPLEMENTAL RESTRAINT SYSTEM

504

1997 LEXUS ES300 (RM511U)

3

Is DTC 31 output again?

PREPARATION:
Clear malfunction code.
CHECK:
(a)

Turn ignition 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)

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

(d)

Using SST, connect terminals Tc and E1 of DLC 1.
SST 09843–18020

(e)

Check DTC.

NO

Using simulation method, reproduce malfunc-
tion symptoms (See page

IN–17

).

YES

Replace airbag sensor assembly.