1999 HONDA CIVIC Ignition switch

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

Troubleshooting
Central Processing Unit (CPUI
Diagnostic Troublo Code IDTC) 81: CPU Disgnosis
- With the ignition switch ON{lll. ABS indicator light doesnot go oft.- With tho SCS servi@ connec-tor conn€cted lsee page 19{6},DTC 81 is indicated.
P.oblem vedfication:1. Erase the DTC.2. Test-drive the vehicle.3. Make sure that the ABS indi,cator light comes on and DTC81 is indicated.
ls DTC 81 indicated?R€pllc6 th. ABS control unh.
The system k OK rt this time.
19-74

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.

Troubleshooting -'96 - 98 Models
Blower Motor Speed
HEATER FAN SWITCH 6P CONNECTOR
Wire side of female terminals
21-a
Blower motor runs. but one orrnore speeds are inoperative,
Chsck for a short or an open inthe wire{s}:Turn the ignition switch ON {ll),and the heater fan switch OFF.
Does the blower motor run?
Check for a shon in th6 wirels):1. Turn the ignition switch OFF.2. Disconnect the blower motor2P connector,3. Remove the center dashboardlower cover (see section 20),and disconnect the heater lanswitch 6P connector,4. Disconnect the blower resistor 4P connector,5. Check for continuity betweenthe No. 2,3, 4 and 5lerminalsof the heater fan switch 6Pconnector and body ground
individually.
ls there continuity?Reolace the heater fan switch,
Repair short in the wire(s)beiween the blower resistor, theheater tan switch and the blowermotor,
To page 21 9

ls there approx. 2 - 3 ohms?
Check for an open in the wire(s):1. Reconnect the blower resistor
4P connector,2. Remove the center dashboardlower cover (see section 20),and disconnect the heater fanswitch 6P connector.3. Turn the ignition switch ON (ll).
4. Ground each of these termi-nals individually in the tollow_ing order: No. 4, 2, 5 and 3.
Does the blower motor run atprogressively higher speeds?Reolace the hoater fan switch.
Repair open or cause ol excessiveresistance in the appropriatewire{sl between the blower resis-tor and the heater {an switch.
Check the blower resislor:1. Turn the ignitjon switch OFF.2. Disconnect the blower resistor 4P connector.3, N4easure the resistancebetween the No. 2 and No. 4
terminals of the blower resis-tor,
BLOWER RESISTOR
HEATER FAN SWITCH 6P CONNECTOR
BLU/WHT
2
16
BLUBLU/YEL
BLU/BLK
JUMPERWIRE
Wire side of female terminals
21-9

Troubleshooting -'96 - 98 Models
Blower Motor
BLOWER MOTOR 2P CONNECTOR
Wi.e side of fernale terminals
f=
l1l
r,l
ruumifalulau**'
I
Fl gr-urwnr
l1|_-_-l
t4 ,t
I
glower motor does not run at all.
Check the No.55 (40A)luse in theunder hood fuse/relay box, andthe No. 17 (7.5 A) luse in theundeFdash luse/relay box.
Repl.ce th. fuse{rl, .nd rochack.
Check the blower motor:1. Connect the No. 2 terminal ofthe blower motor 2P connoctor to body ground with a
lumper wrre.2. Turn the ignition switch ON (ll).
Does the blower motor run?
Chock for an opsn in the wire:1. Disconnect the ,umper wireand the blower motor 2P con-nector,2. Measure the voltage betweenthe No. 1 terminal and bodyground.
ls there battery voltage?
Ch6ck tha blower motor relay:1. Turn the ignition switch OFF.2. Remove the blower motorrelay from the under-hoodfuse/relay box, and test it (see
page 21-49).
Replace tha blower moior reley.
To page 21-11
fo page21'12
21-10

From page 2l 10
Check for an open in the wire:
1. Turn the ignition switch OFF,and disconnect the iLrmPer
2. Remove the center dashboardlower cover (see section 20),
and disconnect the heater fanswitch 6P connector.3. Turn the ignition switch ON (ll).
4. Measure the voltage between
the No. 3 terminal and bodygrou nd.
Repair op.n in th6 wiro betw€enthe blower motor and tho heaterfan switch.
Check for an open in the wire:
1. Turn the ignition switch OFF.2. Check for continuity between
the No. 1 terminal of the heatertan switch 6P connector and
body ground.
Reolaco tho heater fan iwitch
Check tor an op€n in the wire
betw.en the heater tan switchand body ground. ll th€ wilo b OK,
check tor poor ground at G401 and
G102.
HEATER FAN SWITCH 5P CONNECTOR
Wire side oI female terminals
(cont'd)
21-11

Troubleshooting -'96 - 98 Models
From page 21-10
Check the under-hood fuse/relayDOX:N/leasure the voltage between theNo. 3 terminal of the blowermotor relay 4P socket and bodyground,
ls there baftery voltage?
Check lor an open in th€ wire:1. Turn the ignition switch ON (ll).
2. Measure the voltage betweenthe No. 4 terminal of the blow-er motor relay 4P socket andbody ground.
Repair open in tho wire betweenthe No. 17 fuss and tho blowelmotor rclay,
Check for en opon in the wire:1. Turn the ignition switch OFF.2. Check for continuity betweenthe No. 2 terminal of the blow-er motor relay 4P socket andbody ground.
Check foi an open in the wirebetwe€n the blower motor relavand body glound. lf the wiro isOK, check fo. poor ground atG{01 and G4O2.
ls there continuity?
Repair open in the BLU/WHTwire b€tween the blower motorrelav and the blower motor.
Blower Motor (cont'dl
BLOWER MOTOR RELAY 'P SOCKET
1211
tt-l_T
trv)
i
21-12