Lexus SC300 / Lexus SC400. Manual - part 799

RELEASE METHOD OF AIRBAG ACTIVATION PREVENTION
MECHANISM

An airbag activation prevention mechanism is built into the connector for the squib circuit of the supplemen-
tal restraint system. When release of the airbag activation prevention mechanism is directed in the trouble-
shooting procedure, as shown in the illustration of the connectors 1 and 2 below, insert paper which is the
same thickness as the male terminal, between the terminal and the short spring.
CAUTION:



NEVER RELEASE the airbag activation prevention mechanism on the steering wheel pad connector.

NOTICE:



Do not release the airbag activation prevention mechanism unless specifically directed by the

troubleshooting  procedure.



If the paper inserted is too thick the terminal and short spring may be damaged, so always use paper the

same thickness as the male terminal.

–

SUPPLEMENTAL RESTRAINT SYSTEM

TROUBLESHOOTING

RS–91

DTC

14

Open in D Squib Circuit

CIRCUIT DESCRIPTION

The squib circuit consists of the center airbag sensor assembly, spiral cable and the steering wheel pad (squib).
It causes the SRS to deploy when the SRS deployment conditions are satisfied.
For details of the function of each component, see FUNCTION OF COMPONENTS on page 

RS–9

. Diagnostic

trouble code 14 is recorded when an open is detected in the squib circuit.

DTC No.

Diagnosis

14



Open circuit in D+ wire harness or D– wire harness of squib.



Squib malfunction.



Spiral cable malfunction.



Center airbag sensor assembly malfunction.

RS–92

–

SUPPLEMENTAL RESTRAINT SYSTEM

TROUBLESHOOTING

WIRING DIAGRAM

DIAGNOSTIC CHART

DIAGNOSTIC CHART

–

SUPPLEMENTAL RESTRAINT SYSTEM

TROUBLESHOOTING

RS–93

NG

OK

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 D squib circuit.

C

OK

P

Disconnect center airbag sensor assembly connector.

Measure resistance between D+ and D– on spiral cable
side of connector between spiral cable and steering
wheel pad.

Resistance:

Below 1 

Go to Step 

.

RS–94

–

SUPPLEMENTAL RESTRAINT SYSTEM

TROUBLESHOOTING