1998 HONDA CIVIC circuit

tt
(From page 19-68)UNDER.HOOD ABSFUSE/RELAY 8()X
TERMINAL TERMINAL
PUMP MOTOR 2P CONNECTOR
MOTOR +8 lWHTl,$
rv) -
Y
Wire side ot female terminals
\lt
MOTOR +B {RED}MOTOR GND (BLK)
ABS CONTROL UNIT 22P CONNECTOR
(cont'dl
19-69
JUMPER WIRE
Wire side oI female terminals
Check the pump motor circuit:1. Remove the pump motor relay.2. Turn the ignition switch ON (ll).
3. Connect the pump motor relayconnector +8 and MOTOR terminals with a iumper wire tora momenr,
Ch€ck for an open in the pump
moior +B circuit:1. Turn the ignition switch OFF.2. Disconnect the pump motor2P connector,3. Turn the ignition switch ON (ll).
4. Connect the pump motor relayconnector +B and MOTOR ter-minals with a jumper wire.5. Measure the voltage betweenthe pump motor 2P connectorterminal No. l and bodyground.
Does the pump motor operate?
Repaia open in the wire botweentho under-hood ABS fuse/relaybox and pump motor.ls there battery voltage?
Check the pump motor opgra-tion:Connect the battery {+}terminal tothe pump motor 2P connector ter-minal No. 1. and the (-)terminalto
the terminal No. 2 for a moment.
ReDlaco lho modulator unit.(Feulty pump motor)Does the pump motor operate?
Chock for a short to body ground
in the PMR circuit:1. Turn the ignition switch OFF.2. Disconnect the ABS controlunit 22P connector.3. Check for continuity betweenterminal No. 19 and bodygrouno,
Repail opon in ths wirg botwgentho pump motor and bodv ground,
or poor ground (G,!09).
Ropair 3hort to body g?ound intha wire between the under-hood ABS fuse/rclay box andABS cortrol unit.
(To page 19-70)

Troubleshooting
ABS Pump Motor (cont'dl
(From page 19-69)
ABS CONTROL UNIT 22P CONNECTOR
Check tor an opon in the PCOMcircuit:1. Turn the ignition switch OFF.2. Reconnect the ABS controlunit 22P connector.3. Connect the SCS service con-nector,4. Turn the ignition switch ON (ll).
5. Measure the voltage betweenthe pump motor relay connector PCOI,I terminal andbody ground.
Repair opon in tha wiro bEtwoonth. und€r-hood ABS fu3./rclsybox and ABS control unit.ls there approx. 3 V?
Chock for rn op6n in tho PMR cir-cuit:Measure the voltage beNveen theABS control unit 22P connectorterminal No. 19 and body ground.
Ropair opon in tho wira b€twoontho undor-hood ABS fu.e/rel.ybox and ABS control unit.ls there approx. 3 V?
Chock for an opon in ths MCKcircuh:1. Turn the ignition switch OFF.2- Disconnect the SCS serviceconnector.3. Turn the ignition switch ON lll).4. Measure the voltage betweenthe ABS control unit 22P con-nector terminal No. 17 andbody ground while connect-ing the pump motor relayconnector +8 and MOTOR ter'minal with a jumper wire formoment.
Repeir op.n in th. wire batweentho undor-hood ABS fu.o/rol.Vbox rnd ABS control unh.
Ch6ck lor loose ABS contlol unitconnoctors. lf ngc63ary, sub3ti-tute d known-good ABS controlunit and recheck.
n--l
wire side oI temale terminals
19-70

tfMain Relay
Diagnostic Trouble Code {DTC} 54: Msin Relay Diagnosis
YES
NOTE: Reinstallthe fuse if it is OK.
ABS CONTROL UNIT 26P CONNECTOR
Wire side of female terminals
ABS CONTROL UNIT 22P CONNECTOR
B1{WHT/GRNI
\e
PCOMIGRN/WHT}scoM{BLK/WHTI
(cont'd)
19-71
Wire side of female terminals
- With the ignition switch ON
{ll), ABS indic.tor light doesnot go off.- With the SCS 3ervica connoc-
tor connected (s€e pag€ 19-561,
DTC 54 is indicated.
checkthe ABS +B (20 Alfuse.
Replace th6 fuso and rechock.
Ch€ck for an op€n in the 81, 82
circuit:Measure the voltage betweenbody ground and the ABS control
unit 26P connector terminal No. '14
and No. 15 individually.
Repair open in the wire betweonthe ABS control unit and under-hood ABS tuse/relav box.
Check for a short lo body ground
in the PMR circuit:1- Turn the ignition switch OFF.
2. Remove the pump motor relay.
3. Disconnect the ABS controlunit 22P connector.4. Check for continuity betweenterminal No. 19 and bodygrouno.
Repair short to body ground in
the wire between the undor-hood ABS fuse/relay box andABS control unit.
ls there continuity?
Check tor a short to body ground
in the PCOM, SCOM circuit:1. Disconnect the ABS controlunit 26P connector.2. Check for continuity betweenbody ground and the ABS con-trol unit 26P terminals No. 1
and No.2 individually.
. Bepai. short to body ground in
tho PCOM circuit wire betwoenthe ABS control unit and under-hood ABS fu3e/.olay box.. Repair 3hort to body ground inthe PCOM or SCOM circuit wirebetween the ABS control unitand moduletor unit.. Rcplace th6 modulator unit.(Short circuit insido tho unit)
ls there continuity?
{To page 19 72)lr

Troubleshooting
Main Relay (cont'd)
(From page 19'71)
PCOM(GRN/WHTIscoM(BLK/WHT}Check tor a short to powor in thePCOM, SCOM circuit:1. Turn the ignition switch ON r).2. Measure the voltage betweenbody ground and ABS controlunit 26P connector terminalsNo. l and No.2 individually.
. Repair 3hoit to power in ihercOM circuil wire bgtween theABS control unit end unde.-hood ABS fuse/relay box.. Repair sho to powor in thaPCOM oJ SCOM circuit wirobetwoen the ABS control unitand modulator unit.' Repl.co the modul.tor unit.lshort to Dowcr iGido the unit)Replace the ABS control unit.
Vo lta ge
19-72

lgnition Voltage
Diagnostic Trouble Code (DTC) 61: lgnhion Voltage Diagno3is
A8S CONTROL UNIT 26P CONNECTOR
IG2IBLK/BLU}
]Wire side of lemale terminals
- With tha engin€ running, ABSindicator lighl is ON.- With the SCS s€rvice connec-to. conn€ctod ls€€ page 19-561,DTC 61 is indicated.
Problem v€rification:1. Erase the DTC.2. Start the engine.3. Make sure that the ABS ind;cator light comes on and DTC61 is indicated.
ls DTC 61 indicated?The system b OK .t this time.
Check the lG2 cilcuii:Measure the voltage between theABS control unit 26P connectorterminal No. 3 and body ground.
ls there 18 V or above?
lf the vohage is 0 V, check lor anopon in the lG2 circuit.It there is 12 - 17 V. substitute aknown-good ABS colrtrol unit andJecheck.
It
19-73

Heater and Air Conditioning
Heater '.'..""" 21'1
Air Conditioning ......."'.. "' 22-1
SUPPLEMENTAL RESTRAINT SYSTEM (SRS}
The civic sRs includes a driver's airbag located in the steering wheel hub ln addition, all models (except some
models for canada) have a passenger's airbag located in the dashboard above the glove box'
Information necessary to safely service the sRS is included in this service Manual ltems marked with an asterisk (*)
on the contents page include, or are located near, sRs components. servicing, disassembling or replacing these
items will require special precautions and tools, and should therefore be done by an authorized Honda dealer'
@-";;il rendsring the SRS inoperative, which could lead to personal iniury or deaih in the svent of a sev€re
frontal collision. all SRS service work must be pertormed by an authorized Honda d€aler'
. lmploper service procedures, including incorrest removal and instsllation of the sRs, could lead to personal
iniury caused by unintentional deployment of the airbags'
o Do not bump the SRS unit. Otherwise. the system may fait in case of a collision. or the airbags may deploy
when the ignition switch is ON {ll}'
. sRs electrical wiring harncsses are id€ntified by yellow colol coding. Related components ale located in lhe
steering column, front console, dashboard, dashboald lowet panel, and in the dashboard above the glove box'
Do not use electricaltest equipment on these circuits.

Heater
lllustrated Index
'96 - 98 Models ................................ 21'2
'99 - 00 Models ................................ 21'3
Circuit Diagram
'96 - 98 Models .....21-4
'99 - 00 Models ................................ 21-5
Troubleshooting - '96 - 98 Models
Symptom Chart ............................... 21-6
Heater Control Panel Input/
Output Signals ..............,.............. 21-7
Flowcharts
Blower Motor Speed ................... 21-8
Bf ower Motor ,...21'10
Mode Control Motor ............... ,.'.' 21-13
Recirculation control Motor ....... 21-16
Heater Control Panel ................ ... 21 -14
Troubleshooting - '99 - 00 Models
Symptom Chart ............................... 21-19
Seff-diagnosis Function ............,,,.... 21-20
Flowcharts
Air Mix Control Motor ......,.......... 21-21
Mode Control Motor ............... ..... 21 -25
Recirculation Control Motor ....... 21-27
Bf ower Motor Speed .............. .....21'29
Bf ower Motor ....21-31
Heater Control Panel ................,.. 21-35
Heater Control Panel Input/
Output Signals ............................. 21-36
Blower Unit
Repf acement .........21-37
Overhaul ................ 21-38
* Heater Unit
Replacement ....'....21-39
overhaul """" """' 21-4'l
Heater Control Panel
Repfacement .........21'42
Overhaul -'96 - 98 Models ........... 21-43
Temperature Control
Adjustment - '96 - 98 Models """" 21-44
Adiustment - '99 - 00 Models .......21-45
Air Mix Control Motor
Test - '99 - 00 Models ...........' .......21'46
Replacement - '99 - 00 Models ....21'46
Mode Control Motol
Test ................, .,...'.21'47
Replacement '.'."...21-47
Recirculation Control Motor
Test ................. .......21-48
Repf acement ......." 21-48
Relays
Test ................. .......2'l-49
Heater Fan Switch
Test - '96 - 98 Models ............. .......21-49
Mode Control Switch
Test -'96 - 98 Models ..........."....... 21-50
Power Transistor
Test - '99 - 00 Models ....'........ ....".21-50
*: Read SRS Drecautions before working in this area.

Circuit Diagram
'96 - 98 Models
LINDEF NoOD FUSETFELAY 30x
WNTTBLK +WFT
8L|(YEi
LIGHT
Y
I
No1l lS0Al Ni42 (40A)
S;rt' | | lieti{,**i'-t L-:} [:] | h
crca(.-A-o \1 \-r. \-r-1 \'\
!9[1' ? _?__?'? _t__?__t
21-4