sensor TOYOTA SUPRA 1995 Service Repair Manual

Check D squib circuit.
For the connector for the center airbag sensor as-
sembly side) between center airbag sensor assem-
bly and front passenger airbag assembly, measure
the voltage between P
+ and body ground.
Voltage: 0 V
Check P squib circuit.
Disconnect center airbag sensor assembly connec-
tor.
For the connector (on the spiral cable side) between
the spiral cable and steering wheel pad, measure
the voltage between D
+ and body ground.
Voltage: 0 V
Repair or replace harness or connector between
the center airbag sensor assembly and front pas-
senger airbag sensor assembly.
RS±62± SUPPLEMENTAL RESTRAINT SYSTEMTROUBLESHOOTING

Check center airbag sensor assembly.
(1) Turn ignition switch to LOCK.
(2) Disconnect negative (±) terminal cable from the
battery.
(3) Connect connector to center airbag sensor as±
sembly.
(4) Using a service wire, connect P+ and P± on
center airbag sensor assembly side of connec±
tor between center airbag sensor assembly and
from passenger airbag assembly.
(5) Using a service wire, connect P+ and P± on
center airbag sensor assembly side of connec±
tor between center airbag sensor assembly and
front passenger airbag assembly.
(6) Connect negative (±) terminal cable to battery,
and wait at least 2 seconds.
(1) Turn ignition switch to ACC or ON and wait at
least 20 seconds.
(2) Clear malfunction code stored in memory.
(See page RS±47)
(3) Turn ignition switch to LOCK, and wait at least
20 seconds.
(4) Turn ignition switch to ACC or ON, and wait at
least 20 seconds.
(5) Using SST, connect terminals Tc and E
1 of
DLC1 or DLC2.
SST 09843±18020
(6) Check diagnostic trouble code.
Diagnostic trouble code 12 is not output.
Codes other than code 12 may be output at this
time, but they are not relevant to this check.
Replace center airbag sensor assembly.
± SUPPLEMENTAL RESTRAINT SYSTEMTROUBLESHOOTINGRS±63

 
 
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.
Check spiral cable.
Repair or replace spiral cable.
Repair or replace harness or connector between
center airbag sensor assembly and spiral cable.
(1) Turn ignition switch to LOCK.
(2) Disconnect connector between center airbag
sensor assembly and spiral cable.
(3) Turn ignition switch ON.
Measure voltage at D
+ on spiral cable side of connec-
tor between spiral cable and steering wheel pad.
Voltage: 0 V
± SUPPLEMENTAL RESTRAINT SYSTEMTROUBLESHOOTINGRS±65

DTC 13 Short in D Squib Circuit (Between D+
Wire Harness and D±
Wire Harness)
CIRCUIT DESCRIPTION
The D squib circuit consists of the center airbag sensor assembly, spiral cable and steering wheel pad.
It causes the airbag to deploy when the airbag deployment conditions are satisfied.
For details of the function of each component, see FUNCTION OF COMPONENTS on page RS±4.
Diagnostic trouble code 13 is recorded when a short is detected in the D
+ wire harness and D± wire harness
of the squib circuit.
 
 DTC No.
 
 Diagnosis
 
 
 
 
13
 
 
 
 

Short circuit between D+ wire harness and D± wire harness of squib.


D squib malfunction.


Spiral cable malfunction.


Center airbag sensor assembly malfunction.
RS±66± SUPPLEMENTAL RESTRAINT SYSTEMTROUBLESHOOTING

Check center airbag sensor assembly.
(1) Turn ignition switch to ACC or ON and wait at
least 20 seconds.
(2) Clear malfunction code stored in memory. (See
page RS±47)
(3) Turn ignition switch to LOCK, and wait at least
20 seconds.
(4) Remove the service wire which connects D
+ and
D± on spiral cable side of connector between
spiral cable and steering wheel pad.
(5) Turn ignition switch to ACC or ON, and wait at
least 20 seconds.
(6) Using SST, connect terminals Tc and E
1 of DLC1
or DLC2.
SST 09843±18020
(7) Check diagnostic trouble code.
Diagnostic trouble code 13 is not output.
Codes other than code 13 may be output at this
time, but they are not relevant to this check.
Replace center airbag sensor assembly.
(1) Using a service wire, connect D+ and D± on spiral
cable side of connector between spiral cable and
steering wheel pad.
(2) Using a service wire, connect P+ and P± on cen±
ter airbag sensor assembly side of connector
between center airbag sensor assembly and
front passenger airbag assembly.
(3) Connect negative (±) terminal cable to battery, and
wait at least 2 seconds. RS±68
± SUPPLEMENTAL RESTRAINT SYSTEMTROUBLESHOOTING

(See page RS±72).
Check spiral cable.
(1) Disconnect connector between center airbag
sensor assembly and spiral cable.
(2) Release airbag activation prevention mechanism
on center airbag sensor assembly side of airbag
squib connector (See page RS±72).
For the connector (on the spiral cable side) between
the spiral cable and steering wheel pad, measure the
resistance between D
+ and D±.
Resistance: 1 M
or higher
Check harness between center airbag sensor assembly and spiral cable.
(1) Disconnect center airbag sensor assembly
connector.
(2) Release airbag activation prevention mecha±
nism on center airbag sensor assembly
connector. (See page RS±72)
For connector (on the center airbag sensor assem-
bly side) between the spiral cable and center airbag
sensor assembly, measure the resistance between
D
+ and D±.
Resistance: 1 M
or higher.
Repair or replace spiral cable.
Repair or replace harness or connector between
center airbag sensor assembly and spiral cable.
RS±70± SUPPLEMENTAL RESTRAINT SYSTEMTROUBLESHOOTING

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.
Connector center airbag sensor assembly connector.
For the connector (on the center airbag sensor as-
sembly side) between the spiral cable and center
airbag sensor assembly, measure he resistance
between D
+ and D±.
Resistance: 1 k
or higher
Replace center airbag sensor assembly.
Check center airbag sensor assembly.
± SUPPLEMENTAL RESTRAINT SYSTEMTROUBLESHOOTINGRS±71

Airbag Squib: P squib
(Front Passenger Airbag Assembly)
Airbag squib: D squib
(Steering Wheel Pad)
Front Airbag Sensor RH
Center Airbag
Sensor Assembly
Junction Block No.1
Front Airbag Sensor LH
Center Airbag Sensor Assembly Connector (Connector (1))
Airbag Squib Connector (Connector (2))
RELEASE METHOD OF AIRBAG ACTIVATION PREVENTION MECHANISM
An airbag activation prevention mechanism is built into the connector for the squib circuit of the SRS. When
release of the airbag activation prevention mechanism is directed in the troubleshooting procedure, as shown
in the illustration of the connector (1) and (2) below, insert paper which is the same thickness as the male termi-
nal, between the terminal and the short spring.
CAUTION:
wNEVER RELEASE the airbag activation prevention mechanism on the steering wheel pad
connector and front passenger airbag assembly connector.
NOTICE:
wDo not release the airbag activation prevention mechanism unless specifically directed by the
troubleshooting procedure.
wIf 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. RS±72
± SUPPLEMENTAL RESTRAINT SYSTEMTROUBLESHOOTING

DTC 14 Open in D Squib Circuit
CIRCUIT DESCRIPTION
The D squib circuit consists of the center airbag sensor assembly, spiral cable and the steering wheel pad. It
causes the airbag to deploy when the airbag deployment conditions are satisfied.
For details of the function of each component, see FUNCTION OF COMPONENTS on page RS±4. 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.


D Squib malfunction.


Spiral cable malfunction.


Center airbag sensor assembly malfunction.
± SUPPLEMENTAL RESTRAINT SYSTEMTROUBLESHOOTINGRS±73

INSPECTION PROCEDURES [P] Preparation [C] Check
Preparation.
(1) Disconnect negative (±) terminal cable from the
battery, and wait at least 90 seconds.
(2) Remove steering wheel pad (See page RS±10).
(3) Disconnect connector of front passenger airbag
assembly (See page RS±20).
Check D squib circuit.
Disconnect center airbag sensor assembly con-
nector.
For connector (on the spiral cable side) between
the spiral cable and steering wheel pad, measure
the resistance between D
+ and D±.
Resistance: Below 1

Store the steering wheel pad with the front sur-
face facing upward. RS±74
± SUPPLEMENTAL RESTRAINT SYSTEMTROUBLESHOOTING