1999 HONDA CIVIC relay

Circuit Diagram
UNDER-HOOD FUSE/RELAY 8OXIGNITIONSWITCH
WHT/8LI( +WHT
Brake systsm light
passenger's airbag
l----ltlI DUMMY II BESISTOR I
tll
tl
la rl
MEMORY ERASESIGNAT IMES)CONNECTOR I2P)
GRY{GRN)
I
BRN BRN
tl.-l- .-r-\./ \./
ECM/PCM SERVICECHECKCONNECTOR
ILT 8LU
I
t'7
DATA LINKCONNECTOR{DLC) {r6P)
GRY GRY(GRN) IGNN)
V:
G801
Teminalside oi thal€ terminals
24-6
4''
SRS UNIT TERMINALSG40tG402
SBS INDICATOR CIRCUIT{ln the gauge assembly)
PGM_FI
DRIVER'SAIRBAGINFLATOR
10 14 r 13 6 7(VAl 3{VBlSRS UNIT16 17 t5 9 18 8

SRS Indicator Light Wire Connections
SRS Indicator Light Power Circuit
DASHBOARD WIRE HARNESS
To UNDER-DASHFUSE/RELAY BOX -
20P CONNECTOR
SRS Indicato. Light Control Circuit
To SRS UNIT
tI
SRS MAIN HARNESS
C41 1, C412 : Terminal sido of mdlo t6rminalsC501, C5O2, C508, C801. C802, C807 : Wi.6 sidc of fomalo t.rminals
MAIN WIBE HARNESS
BLU
C508 -+ To GAUGE ASSEMBLY
c41 1
To GAUGE ASSEMBLY
at
C501 : DASHBOARDWIRE HARNESS 2oP CONNECTORC508 : DASHBOARD wlRE HARNESS 5P CONNECTORC801 : SRS MAIN HARNESS 2P CONNECTORC807 : SRS MAIN HARNESS 18P CONNECTOR
C802 : SRS MAIN HARNESS 3P CONNECTORC412 : MAIN WIRE HARNESS 3P CONNECTORC41 1 : MAIN WIRE HARNESS 24P CONNECTORC502 : DASHBOARD WIRE HARNESS 24P CONNECTOR
GRY
OI
24-25

Troubleshooting
The SRS Indicator Light Doesn't Come On
CAUTION: Whonever ths ignition switch is ON {ll}, or
has been turned OFF tor less than three minutes. be
careful not to bump the SRS unit; the airbagls) could
accidentally deploy .nd caus6 damage or iniuri€s.
Check tho pow€r supply (fuse):
Turn the ignition switch ON (ll), and check whether the otherindicator lights come on (brake system, etc.).
Oo the other indicator liohts como on?
YESNO
Check th6 fuso:Check the No. 25 {7.5 A) fuse in the under-dash tuse/relayb"t
ls th6 tu36 OK?
NOYES
Check the bulb:Replace the No. 25 (7.5 A) fuse, and check that theSRS indicator light comes on.
Doos the SRS indicator liqhl come on7
I YES No
END
Check tho wire harns b€twecn fus6 and gauge aasambly:Check for an open in the wire harness between luseNo. 25 {7.5 A) and the gauge assembly, and repair. Checkthat the SRS indicator light comes on.
Doo. tho SRS indic.tor light como on?
I yEs No
I
END
Check tho SRS indicator light bulb:1. Turn the ignition switch OFF.2. Remove the gauge assembly.3. Check for blown SRS indicator light butb.
ls the SRS indicator light bulb OK?
NOYES
Ch.ck the SnS indicator liglrt circuit:Replace the bulb, and reconnect the gauge assemblyconnectors. Then turn the ignition switch ON {ll}.
Ooes th6 SRS indicato. llght come on?
I YEs No
:ND
lAl To page 24-27
24-26
lB'J fo page 24-27
))
No. 25 (7.5 Al FUSE

)The SRS lndicator Light Doesn't Go Off -'96 - 97 Models
CAUTION: Whenever the ignition switch is ON (ll), or has been turned OFF for less than three minutes, be careful not to
bump the SRS unit; the airbag{sl could accidentally deploy and cause damage or iniuries
Try to reproduce lhe SRS indicator light:
1. Erase the DTC memory (see page 24'15).
2. Turn the ignition switch OFF, and wait for ten seconds.
3- Turn the ignition switch ON {ll), and check that the SRS indi
cator light comes on for about six seconds and goes off
Does the SRS indicEtor light stay on?
[*NO
Intermittent lailure, system is OK at this time. See
Troubloshooting Int6rmittent Failures on page 24'15
Ch€ck the No. 13 {15 A} and No. 23 (10 A) fuses:
1. Turn the ignition switch OFF.
2. Check for blown No. 13 (15 A) and No.23 (10 A)fuses in
the under dash fuse/relay box.
Are the fuses OK?
vEs No
Replace the luses, and erase the memory1. Replace the fuses.2. Connect the SCS service connector to the MES con
nector.3. Erase the DTC memory (see page 24 15).
4. Turn the ignitaon switch OFF, then disconnect the SCS
service connector from the MES connector.5. Turn the ignition switch ON (ll).
Does the sRS indicato, tigt t go or "ne. "ii--JJl
-I YEs NO1
ENDi
Conlirm the DTC, and continue troubl6shootilg.
Check for an open in the SRS main harness {VA linell'1. Tu.n the ignition switch OFF.
2. Disconnect the battery negative cable, then disconnect
the positive cable, and wait for three minutes.
3. Disconnect the driver's (and front passenger's) airbag
connectorls) (see page 24 11).
4. Disconnect the SBS main harness '18P connector from
the sRS unir.5, Reconnect the battery positive cable, then reconnect the
negative cable.6. Connect a voltmeter between the No. 7 tetminal (+) of
the SRS main harness 18P connector and ground.
7. Turn the ignition switch on.
b there battery voltageT
YESNO
(A)
To page 24 30
Open in the SRS main harness IVA line); replace the SRS
main harness.
l.J
SBS MAIN
(cont'd)
No. 't3 {15 Al FUSE
SRS UNIT
HARNESS 18P CONNECTOR
II
24-29

Troubleshooting
The SRS Indicator Light Doesn't Go Off -'98 - 00 Models
CAUTION: Whenever the ignition switch is ON {ll}, orhas b66n turned OFF for less than three minutes, becareful not to bump the SRS unit; the airbags coutdaccidentally deploy and cause damage or iniuries.
No. 23 {10 Al FUSEFUSE/RELAY BOX
SRS MAIN HARNESS 18P CONNECTOR
Try to reproduce the SRS indic.tor light:1. Erase the DTC memory (see page 24-15).2. Turn the ignition switch ON (lt), and check that the SRSindicator light comes on for about six seconds and ooesol1.
Intormittent lailulo, systom is OK atthistime. Soo Troublel. o.mittgnl Failuros on paqe24-15.
Check the No. 23 (10 Alfuse:1. Turn the ignition switch OFF.2. Check for blown No. 23 (10 A) tuse in the under,dashfuse/relay box.
Replace ihe fus€, and 6.ase the momory1. Replace the No. 23 110 A) fuse.2. Erase the DTC memory (see page 24,15).3. Turn the ignition switch ON (ll).
Doos the SRS indicator light go off after 3ix second3?
Check tor an open in the SRS msin harness {VB lincl:1. Disconnect the battery negative cable, then disconnectthe positive cable, and wait tor three minutes.2. Disconnect the driver's (and front passenger,s) airbagconnector(s) (see page 24-11).3. Disconnect the SRS main harness 18p connector Iromthe sRs unit.4. Reconnect the battery positive cable, then reconnect thenegative cable.5. Connect a voltmeter between the No. 3 terminal (+) ofthe SRS main harness 18P connector ano qrouno.6. Turn the ignition switch ON {ll).
(A)
To page 24-35
24-34

Troubleshooting
No DTG -'98 - 00 Models (cont'dl
trom page 24 39
SRS MAIN HARNESS2P CONNECTOB
SRS MAIN HARTESS18P CONNECTOR
FUSE/RELAY BOX
c807
c807
Wir€ side ot fsmaleterminals
SRS MAIN HAR ESSlAP CONNECTOR
(Bi
Check for short to ground in iho SRS main ha.no$:1. Disconnect the SRS main harness 2P connector from theunder-dash fuse/relay box.2. Check resistance between the No. 7 terminal of the SFSmain harness 18P connector and ground. There shouldbe 1.0 MO or more.
ls lha r6i3tlnce as sp.cilied?
YESNO
Short to ground in the und..-d.sh tu3a/r.lay box;roplace the undsr-dlrh tu!6/rahy box.
Short to ground in fho SRS main harness; rsplecc the SRSmain htrnors.
Check lor an open in the SRS main harn€ls:1- Turn tho ignition switch OFF.2. Disconnect the baftery negative cable, then disconnectthe positive cable, and wait for three minutes.3. Disconnect the driver's (and front passenger's) airbagconnector(sl (see page 24-11).4. Disconnect the SBS main harness 18P connector tromthe sRs unit.5. Reconnect the battery positive cable, then reconnect thenegative cable.6. Connect a voltmeter between the No. 7 terminal ol theSFS main harness 18P connector and qro!nd.7. Turn the ignition switch ON (ll), and measure
Poor contact rt the SRS main harness 18P conn.ctor:chock th€ connectoi.. ll th. connector is OK, iubstitute a known-good SRSunit, and recheck.. lf tho pioblem is still pres6nt. replace the SRS mlinhaanos3.
(A) From page 24 39
To page 24.41
24-40

)
From page 24-40
Check for an open in the SRS main harn6s:
1. Turn the ignition switch OFF.
2. Disconnect the SRS main harness 2P connector from the
under-dash fuse/relay box
3. Check resistance between the No. 1 terminal ol the SRS
main harness 2P connector and No. 7 terminal of the
SRS main harness 18P connector.
Thereshouldbe0 05O
ls the resistance es specitied?
YES
Poor contact at the SRS main hatness 2P connector;
check the connector-. It the connector i3 OK, substitute a known-good und€r-
dash fuse/relav box, and recheck..ll the Droblem i5 still pres€nt, replace lhe SRS main
harness.
NO
Open in the SRS main hsrness; leplaco the SRS main har-
ness.
)
FUSE/RELAY BOX
SRS MAIN HARNESS18P CONNECTOR
c807
Wire side of femaleterminals
SRS MAIN HARNESS2P CONNECTOR
24-41
lrt

Troubleshooting
DTC 9-2
CAUTION: Whenever the ignition switch is ON 0l), ofhas been turned OFF lor lass than three minutes, becareful not to bump the SRS unit; the airbag(s) couldaccidentally deploy lnd caqse damage or iniuries.
Check the tu.c:1. Turn the ignition switch OFF.2. Check for blown No. 23 (10 A) fuse in the under,dashfuse/relay box.
Replace the tuse. Turn the ignition switch ON lll) , and checkthat the fuse doesn't blow.
Th6 problem hs3 disappe.rod, TGt-dJiv€ the vehiclo and3ee Troublerhooting Intermiftcnt Failuro3 on paqo 2l-15.
Check tol short to ground betwe.n tho unde.-da3h fus./r.ley box and the SRS unit.1. Turn the ignition switch OFF.2. Disconnect the baftery negative cable, then disconnectthe positive cable, and waittorthree minutes.3. Disconnect the driver's (and front passenger,s) airbagconnector(s) (see page 24-11).4. Disconnect the SRS main harness 1gp connector fromthe sRs unit.5. Check resistance between the No. 3 terminal of the SRSmarn harness 18P connector and ground,There should be 1 MO or more.
Feufty SRS unh; rcphce the SRS unit lsee pag.2+761.
(A)To page 24-65
To page 24-65
No. 23 lr0 Al FUSEFUSE/RELAY BOX
!
SRS MAIN HARNESS18P CONNECTORSRS UN'T
24-64
I
SRS MAIN HARNESS 18P CONNECTOR
Otf