1996 TOYOTA TERCEL airbag sensor

R14285 AB0119H00021
Airbag Sensor Assembly ON
IG2 ACC
(+) (-)
DI-172
- DIAGNOSTICSSUPPLEMENTAL RESTRAINT SYSTEM
1996 TERCEL (RM440U)
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 diagnostic
system malfunction.
DTC 31 is recorded when occurrence of a malfunction in the airbag sensor assembly is detected.
DTC No.DTC Detection ConditionTrouble 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 indi-
cated by the malfunction code other than code 31.
1 Preparation (See step 1 on page DI-177)
2 Check voltage at IG2 and ACC of airbag sensor assembly.
PREPARATION:
(a) Connect negative (-) terminal cable to battery.
(b) 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 page
CH-2).
OK
DI4MF-02

AB0118
R13006AB0119
FI1394
H00022
ACCON
or
DLC1
E1
TcCode 31
- DIAGNOSTICSSUPPLEMENTAL RESTRAINT SYSTEM
DI-173
1996 TERCEL (RM440U)
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-16).
YES
Replace airbag sensor assembly.

R14286R12689R14725H08146
P+
P-
Airbag Sensor
Assembly P Squib
D SquibSpiral
CableP-
P+
DI-174
- DIAGNOSTICSSUPPLEMENTAL RESTRAINT SYSTEM
1996 TERCEL (RM440U)
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 FUNCTION OF COMPONENTS on page RS-2.
DTC 54 is recorded when an open is detected in the P squib circuit.
DTC No.DTC Detection ConditionTrouble 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
Refer to page DI-155 for the WIRING DIAGRAM.
INSPECTION PROCEDURE
1 Preparation (See step 1 on page DI-177)
2 Check P squib circuit.
PREPARATION:
Using a service wire, connect P+
and P- on airbag sensor as-
sembly connector.
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: Below 1 W
NG Repair or replace harness or connector be-
tween airbag sensor assembly and front pas-
senger airbag assembly.
OK
DI4MH-02

AB0069
AB0118
R13006W01934
AB0119
W02045
H00024
P+
P-
Airbag Sensor
Assembly
P Squib
D SquibSpiral
Cable
ACCON
or
DLC1
E
1TcCode 54
- DIAGNOSTICSSUPPLEMENTAL RESTRAINT SYSTEM
DI-175
1996 TERCEL (RM440U)
3 Check airbag sensor assembly.
PREPARATION:
(a) Connect connector to airbag sensor assembly.
(b) Using a service wire, connect P
+ and P- on airbag sensor
assembly side of connector between airbag sensor as-
sembly and front passenger airbag assembly.
(c) 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-148).
(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 54 is not output.
HINT:
Codes other than code 54 may be output at this time, but they
are not relevant to this check.
NG Replace airbag sensor assembly.
OK

R05909
AB0118
R13006AB0119
W02045H00025
Airbag Sensor
Assembly
P Squib
D SquibSpiral
Cable
ACCON
or
DLC1
E
1TcCode 54
DI-176
- DIAGNOSTICSSUPPLEMENTAL RESTRAINT SYSTEM
1996 TERCEL (RM440U)
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 ignition switch to ACC or ON and wait at least 20 se-
conds.
(b) Clear malfunction code stored in memory (See page
DI-148).
(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 DLC1.
SST 09843-18020
(f) Check DTC.
OK:
DTC 54 is not output.
HINT:
Codes other than code 54 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.

H09396
MAIN
FL
B
ALT
B-RB-R
2 2
Engine
Room
R/B
AM1
W-GDriver Side J/B
1
1J
1BW-G 2ACC
AM13
B-Y4
1B
1H
CIG/RADIO Driver Side J/B
G-R*1
10
ACCAirbag
Sensor
Assembly
8
*2
B-OIG2 *1
9
7
*2 2
1H 1B5
IGN B-W 6
AM2
Ignition
Switch 7 B-R 12
IC1 B-R
2
AM2
EA2 1
B*1: USA
*2: CANADA EA214
- DIAGNOSTICSSUPPLEMENTAL RESTRAINT SYSTEM
DI-177
1996 TERCEL (RM440U)
DTC Normal Source Voltage Drop
CIRCUIT DESCRIPTION
The SRS is equipped with a voltage-increase circuit (DC-DC converter) in the airbag sensor assembly in
case the source voltage drops.
When the battery voltage drops, the voltage-increase circuit (DC-DC converter) functions to increase the
voltage of the SRS to normal voltage.
The diagnosis system malfunction display for this circuit is different to other circuits-when the SRS warning
light remains lit up and the DTC is a normal code, source voltage drop is indicated.
Malfunction in this circuit is not recorded in the airbag sensor assembly and the source voltage returns to
normal, the SRS warning light automatically goes off.
DTC No.DTC Detection ConditionTrouble Area
(Normal)Source voltage drop.
Battery

Airbag sensor assembly
WIRING DIAGRAM
DI4MI-02

R05894 AB0117
H00001
Airbag Sensor
Assembly LOCK
Spiral
Cable D SquibP Squib
R14285 AB0119H00021
ON
Airbag Sensor Assembly
ACC
IG2
(+) (-)
DI-178
- DIAGNOSTICSSUPPLEMENTAL RESTRAINT SYSTEM
1996 TERCEL (RM440U)
INSPECTION PROCEDURE
1 Preparation.
PREPARATION:
(a) Disconnect negative (-) terminal cable from the battery,
and wait at least 90 seconds.
(b) Remove steering wheel pad (See page SR-13).
(c) Disconnect connector of front passenger airbag assem-
bly (See page RS-21).
(d) Disconnect connector of airbag sensor assembly
(See page RS-33).
CAUTION:
Store the steering wheel pad with the front surface facing
upward.
2 Check source voltage.
PREPARATION:
(a) Connect negative (-) terminal cable to battery.
(b) Turn ignition switch ON.
CHECK:
Measure voltage at IG2 or ACC on sensor and operate electric
system. (defogger, wiper, headlight, heater blower, etc.)
OK:
Voltage: 10 - 14 V
NG Check the harness between battery and airbag
sensor assembly, check the battery and charg-
ing system.
OK

H00003
ON
- DIAGNOSTICSSUPPLEMENTAL RESTRAINT SYSTEM
DI-179
1996 TERCEL (RM440U)
3 Does SRS warning light turn off?
PREPARATION:
(a) Turn ignition switch to LOCK.
(b) Connect steering wheel pad connector.
(c) Connect front passenger airbag assembly connector.
(d) Connect airbag sensor assembly connector.
(e) Turn ignition switch ON.
CHECK:
Operate electric system checked in defogger, wiper, headlight,
heater blower, etc. and check that SRS warning light goes off.
NO Check for DTCs. If a DTC is output, perform trou-
bleshooting for the DTC. If a normal code is out-
put, replace airbag sensor assembly.
YES
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.