1996 HONDA CIVIC srs unit

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Troubleshooting
t)
Self-diagnostic Procedures
The self-diagnostic function of the SRS system allows it to locate the causes of system problems and to store this informa' I
tion in memory. For easier troubleshooting, this data can be retrieved via a data link circuit l
. When you turn the ignition switch ON (ll), the SRS indicator will come on. ll it goes off after six seconds. the system is
norma l.
. lf there is an abnormality, the system locates and defines the problem, stores this information in memory, and turns
the sRS indicator light on. The data will remain in the memory even when the ignition switch is turned off or if the bat-
tery is disconnected.
o when you connect the scs service connector to the service check connector (2P), and turn the ignition switch oN (ll),
thesRsindicator|ightwi||indicatethediagnostictroub|ecode(DTC)bythenumberofb|inks.
. After reading and recording the DTC. proceed with the troubleshooting for this code'
Precauiions
.Useon|yadigita|mU|timetertocheckthesystem'|fit,snotaHondamu|timeter,makesureitsoutputisl0mA(0.01A)
or|esswhenSwitchedtothesma||estva|ueintheohmmeterrange,AtesterwithahigheroUtpUtcoulddamagethe
airbag circuit or cause accidental airbag deployment and possible injury'
r when-ever the ignition switch is oN (ll). or has been turned oFF for lessthan three minutes, be careful nottobumpthe
SRS unit; the airbags could accidentally deploy and cause damage or injuries
. Before you ,"n1ou" th" SRS main harness, disconnect the driver's airbag connector (and the front passenger's airbag
connector).
. Make sure the battery is sufficiently charged {see section 23}. lf the battery is dead or low, measuring valLles won t be
correct.
. Do not touch a tester probe to the terminals in the sRS unit or harness connectors, and do not connect the terminals
with a jumper wire. Use only the backprobe set or the special tools'
For backprobing spring-loaded lock type connectors, refer to page 24-9'
Reading the DTC
when the SRS indicator light is on, read the DTC using one of these methods:
A. Connect the Honda PGM Tester to the 16P Data Link Connector {DLC), and follow the tester's prompts lf the tester
indicatesnoDTc,DTcg-1orDTc9-2,doub|e-checkbyjumpingtheservicecheckconnectorandwatchingthesRS
indicator light (see next Page)
HONDA PGM TESTER
DATA LINK CONNECTOR Il6PI
l,
24-13

Troubleshooting
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B. The SRS indicator light can also indicate the DTC by the number of blinks when the SCS service connector is connect-ed to the service check connector (2P).
1. Turn the ignition switch OFF, and wait for ten seconds. Then connect the SCS service connector to the service checkconnector (2P). lf you do not wait ten seconds, the SRS unit will not be completely reset and will not output DTCS.
SERVICE CHECKCONNECTOR {2PIIGRY, GRYI or IGRN, cRN]SCS SERVICE CONNECTOR07PAZ - (m10100
l.-zs
2. Turn the ignition switch ON (ll). The SRS indicator light comes on for about six seconds and goes off. Then it will indi,cate the DTC:- The DTC consists of a main code and a sub-code.- Including the most recent problem, up to three different malfunctions can be indicated.- In case of a continuous failure, the DTC will be indicated repeatedly (see example 1 below).- In case of an intermittent failure, the SRS indicator light will indicate the DTC one time, then it will stay on (see exam-ple 2 below).
lf both a continuous and an intermittent failure occur, both DTCS will be indicated as continuous failures.- In case the system is normal (no DTC), the SRS indicator light will stay on (see example 3).3. Read the DTC.
4. Turn the ignition switch OFF, and wait for ten seconds. Then disconnect the SCS service connector from the servicecheck connector (2P).
Examples of DTC Indications:
1. Continuous fallure, SRS Indicator Light isl
- Main @de
DTC21Mosr raenr probtsm
Intermittent failure, SRS lndicator Light is:
-lF- rM.in code ir) Sub.code (2)
DTCI2
-'l F --l FMarn code (11 Sub code t1t
DTCl1Thnd.most recenl
Lrghr srays on rn ca* ol
r --
2.
3. No
ON
sutb chek __.1penod
24-14
rmal (no failure), SRS
DTC5l
Indicator Light is:
rl
No OTC, system is norhal, rhe

)Erasing the DTC Memory
To erase the DTC(s) from the SRS unit, use a Honda
PGM Tester (see the Honda PGM Tester SRS vehicle
System Supplement) or the following procedure
1. Make sure the ignition switch is OFF
2. Connect the SCS service connector to the MES con-
nector (2P). Do not use a jumper wlre.
]P,
&
.!--J
MEMORY ERASE
SIGNAL (MESI CONNECTOR I2PI
IGRY, GRYI or [GRN, GRNI
SCS SERVICE CONNECTORo?PAZ - 0010100
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7.
Turn the ignition switch ON (ll).
The SRS indicator light comes on for about six sec-
onds and goes off. Remove the SCS service connec-
tor from the MES connector (2P) within four seconds
after the SRS indicator light went off.
The SRS indicator light comes on again. Reconnect
the SCS service connector to the lvlES connector
(2P) within the four seconds after the SRS indicator
light comes on.
The SRS indicator light goes off. Remove the SCS
service connector from the MES connector (2P)
within four seconds.
The SRS indicator light indicates that the memory is
erased by blinking two times.
Turn the ignition switch OFF, and wait for ten sec-
onos.
8.
SRS indictlorlighi
MESconncclottcaminals
CONNECTED
O,
DISCONI{ECTED
24-15
Troubleshooting Intermittent
Failures
lf there was a malfunction, but it doesn't recur, it will be
stored in the memory as an intermittent failure, and the
SRS indicator light comes on.
Afte. checking the DTC, troubleshoot as lollows:
1. Read rhe DTC {see "Reading the DTC"}.
Erase the DTC memory (see "Erasing the DTC
Memory").
With the shifi lever in neutral, turn the ignition switch
ON (ll), and lei the engine idle.
The SRS indicator light comes on for about six sec-
onds and goes off.
l*F
ON
tl-- -l
Shake the wire harness and the connector, take a test
drive (quick acceleration, quick braking, cornering),
and turn the steering wheel fully left and right, and
hold it there for five lo ten seconds to find the cause
of the intermittent failure.
lf the problem recurs, the SRS indicator light will
stay on.
-q 6a.c f'-
:q
Problem recurs, light stays on
3.
4.
6.lf vou can't duplicate the intermittent failure, the sys-
tem is OK at this time.

Troubleshooting
SRS Unit ldentification
+: On '98 - 00 models, the troubleshooting procedures are different for each type of SRS unit. ldentifv the SRS unit in thevehicle using the chart below, then follow the proper flowchan in the following pages.
'98 - 00 Model SRS units
MAKERIDENTIFICATION
MARK*Remark
NECM1Driver's airbag only
M1Driver's & Passenger's airbags
KEIHINM2Driver's & Passenger's airbags
SIEMENSM3Driver's & Passenger's airbags
'96 - 97 Model SRS units
LABEL IIDENTIFICATION MARK)
MAKERPARTS NUMBERRemark
NEC77960-S04-C81Driver's airbag only
77960-S04-N81Driver's & Passenger's airbags
TAKATA77960-S04-N82Driver's & Passenger's airbags
SIEMENS77960-S02-A81Driver's & Passenger's airbags,'97 Model only
24-16
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Diagnostic Trouble Code (DTG) Chart -'96 - 97 Models
t
SRS indicator lightDTCPossible causeCorrectiv6 actionSae page
doesn't come on
none(doesn't
come on)
Faulty SRS indicator light circuitTroubleshooting24-26
comes on
none *4
(doesn't
go off)
Faulty SRS indicator light circuit, internal
failure of SRS unit, faulty SRS power supply.
Troubleshooting
24-29
1-1Open in the driver's airbag inflator24-42
lncreased resistance in the driver's aarbag
inflator24-42
l-3Short to another wire in the driver's airbag
inflator or decreased resistance
Short to Dower in the driver's airbag inflator
Short to ground in the driver's airbag inflator
24-44
1-424-46
1-524-48
2-1
With front passenger's airbag:
Open in the passenger's airbag inflator
Without front Passenger's airbag:
ODen in the dummy resistor
24-50
24-54
With front passenger's airbag:
Increased resistance in the passenger's airbag
inflator
Without front Passenger's airbag:
lncreased resistance in the dummy resistor
24,50
24-54
2-3
With front passenger's airbag:
Shon to another wire in the passenger's
airbag inflator or decreased resistance
Without tront passenger's airbag: Troubleshooting
Short to another wire in the dummy resistor
or decreased resistance
24-52
24-59
2-4
With front passenger's airbag:
Short to power in the passenger's airbag
inJlator
Without front Passenger's airbag:
Short to power in the dummy resistor
24-54
24-60
With front passenger's airbag:
Short to ground in the passenger's aarbag
inflator
without front passenger's airbag:
Short to ground in the dummy resistor
24-56
24-61
(cont'd)
24-17
a,

Troubleshooting
Diagnostic Trouble Code (DTCI Ghart -'96 - 97 Models (cont'd)
NOTE:* l: In case of an intermittent failure DTC g-1, it means there was an internal failure of the SRS unit or a faultv SRS indicator light circuit. Do the troubleshooting for intermittent failures (see page 24-15).*2: lt both DTC 9-2 and DTC 5-1 are indicated, do the troubleshooting for DTC g-2.*3: Apply to the '97 model coupe HX and DX.*4: DTC cannot be read with a Honda PGM Tester; check by jumping the SCS service connector.
24-18
.
Possiblg cause Cortestive action
5 3 I Internal failure of the SRS unitSRS unit
replacement
lnternal failure of the SRS unitSRS unit
replacement
Internal failure of the SRS unit
Internal failure of the SRS unitSRS unit
replacement
Internalfailure of the SRS unit ortwo failures at atime
8-6*3 Internalfailure ofthe SRS unit
Internal failure of the SRS unit
Faulty SRS power supply (VB line)
SRS unit replacement code (SRS unit must not
be used any longe.)
J

)Diagnostic Trouble Code (DTC) Chart -'98 - 00 Models
NEC SRS Unit
Ir
SRS indicator lightDTCPossible causeCorrestive actionSee page
doesn't come on
none
(doesn't
come on)
Faulty SRS indicator light circuitTroubleshooting24-26
comes on
none*3
(doesn't
go off)
Faulty SRS indicator light circuit, internal
fallure of SRS unit, faulty SRS power supply
(VB line)
Troubleshooting24-34
No DTC*3(lis ht
comes on
after self-
diagnosis)
Faulty SRS power supply (VA linelTroubleshooting24-39
l-1Open in the driver's airbag inflator
Troubleshooting
24 42
Increased resistance in the driver's airbag
inflator24-42
Short to another wire in the driver's airbag
inflator or decreased resistance24-44
't -4Short to power in the driver's airbag inflator24-46
t-5Short to ground in the driver's airbag inflator24-48
With front passenger's airbag:
Open in the passenger's airbag inflator
Without front passenger's airbag:
Open in the dummv resistor
24-50
24-54
With front passenger's airbag:
Increased resistance in the passenger's airbag
inflator
Without front passenger's airbag:
Increased resistance in the dummy resistor
24-50
24-58
with front passenger's airbag:
Short to another wire in the passenger's
airbag inflator or decreased resistance
Without front passenger's airbag:
Short to another wire in the dummy resistor
or decreased resistance
Troubleshooting
24-52
24,59
2-4
With front passenger's airbag:
Short to power in the passenger's airbag
inflator
Without front passenger's airbag:
Shon to power in the dummy resistor
24-54
24-60
With front passenger's airbag:
Short to ground in the passenger's airbag
inflator
Without front passenger's airbag:
Short to ground in the dummy resistor
24-56
24-61
(cont'd)
24-19
l,

Troubleshooting
Diagnostic Trouble Code (DTC) Chart -'98 - 00 Models {cont'dl
NOTE:* 1: In case of an intermittent failure DTC 9-1, it means there was an internal failure of the SRS unit or a faulty SRS indica-
tor light circuit. Do the troubleshooting for intermittent failures (page 24-'15).*2: In case of an intermittent failure DTC 9-2, it means there was an internal failure of the power supply {VB line). Do the
troubleshooting for intermiftent failures.*3: DTC cannot be read with a Honda PGM Tester; check by jumping the SCS service connector.
24-20
\
SRS indicator lightDTCPossible causeCorrectiYe actionSee page
comes on
5-1lnternal failure of the SRS unitSRS unit
replacemenl24-765-4
6-1
lnternal failure of the SRS unitSRS unit
replacement24-7 66-2
o-5
6-4
7-1
lnternal failure of the SRS unitSRS unit
replacement24-76
7-3
8-1lnternal failure of the SRS unitSRS unit
reptacement24-7 68-2
8-6Internal failure of the SRS unit or two failures
at a trmeTroubleshooting24-62
g_1*r *3lnternal failure of the SRS unitSRS unit
replacement24-7 6
9-2+2 *3lnternal failure of the SRS unit5l|5 Untr
replacement24-76
10-1SRS airbags deployed (SRS unit must be
reDlaced)
SRS unit
replacement24-76