Lexus SC300 / Lexus SC400. Manual - part 794

DIAGNOSTIC CHART

DIAGNOSTIC CHART

(See page 

RS–49

).

(See page 

RS–48

).

–

SUPPLEMENTAL RESTRAINT SYSTEM

TROUBLESHOOTING

RS–71

WIRING DIAGRAM

DIAGNOSTIC CHART (Cont’d)

DIAGNOSTIC CHART (Cont’d)

(See page 

RS–49

).

RS–72

–

SUPPLEMENTAL RESTRAINT SYSTEM

TROUBLESHOOTING

OK

NG

INSPECTION PROCEDURE

1

Preparation.

P

1.

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

2.

Remove steering wheel pad (See page 

RS–19

).

3.

Disconnect connectors of front passenger airbag
assembly (See page 

RS–32

).

Caution:

Store the steering wheel pad with the

surface facing upward.

2

Check front airbag sensor circuit. (Measure resistance between terminals +SR and –SR, +SL
and –SL of center airbag sensor assembly connector.)

C

OK

P

Disconnect center airbag sensor assembly connector.

Measure resistance between terminals +SR and –SR,
+SL and –SL of harness side connector o center airbag
sensor assembly.

Resistance:

755 

 – 885 

Go to step 

–

SUPPLEMENTAL RESTRAINT SYSTEM

TROUBLESHOOTING

RS–73

OK

NG

OK

NG

3

Check front airbag sensor circuit. (Measure resistance between terminals +SR and +SL of cen-
ter airbag sensor assembly connector and body ground.)

C

OK

Measure resistance between terminals +SR, +SL of
harness side connector of center airbag sensor assem-
bly and body ground.

Resistance:

1 M

 or higher

Repair or replace harness or connector between center
airbag sensor assembly and front airbag sensor (See
page 

RS–48

).

4

Check D squib circuit.

C

OK

For the connector (on the spiral cable side) between the
spiral cable and steering wheel pad, measure the resist-
ance between D+, D– and body ground.

Resistance:

1 M

 or higher

Go to step 



RS–74

–

SUPPLEMENTAL RESTRAINT SYSTEM

TROUBLESHOOTING