1999 HONDA CIVIC electrical

Precautions/ Procedures
)General Precautions
r Carefully inspect any SRS part before you install it Do
not install any part that shows signs of being dropped
or improperly handled' such as dents, cracks or defor-
mation:
- Airbags- Cable reel
- SRS unit
-
Use only a digital multimeter to check the system lf
it's not a Honda multimeter, make sure its output ls
1O mA (0.01 A) or less when switched to the smallest
value in the ohmmeter range. A tester with a higher
output could damage the airbag circuit or cause acci-
dental deployment and possible injury'
I Do not install used SRS parts from another vehicle
When making SRS repairs, use only new pans'
) Except when performing electrical inspections'
always disconnect both the negative cable and posl-
tive cable from the battery, and wait at least three
minutes before beginning work
r Replacement of the combination light and wiper/
washer switches and cruise control switch can be
done without removing the steering wheel:
- Combinalion light and wiper/washer switch replace
ment, see section 23
- Cruise control sevresume switch replacement' see
section 23.
. 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(s) could accidental-
ly deploy and cause damage or injury'
. Whenever the airbag{s) has(have) been activated'
replace the SRS unit.l,
2+7
Airbag Handling and Storage
Do not try to disassemble the airbag assembly. lt has no
serviceable parts Once an airbag has been operated
(deployed). it cannot be repaired or reused'
For temporary storage of the airbag assembly during ser-
vice. olease observe the following precauttons:
. store the .emoved airbag assemblv with the pad sur-
face uo The driver's (and front passenger's) airbag
connecto''s'-as {have) a built.in short contact (see
page 2a-l 1
: | ..r r-+r-a k imninncrlv slorcd lace down,-""dd.r6t dtatltt-,tl could propel the unit whh enough
force lo c.usa 3a.ix! intury
AIRBAG CONNECTORS(With built in shon contact)
. Store the removed airbag assembly on a secure flat
surface away from any high heat source {exceeding
212"FI1OO"CJ and free of any oil' grease, detergent or
water.
CAUTION: lmproper handling or storage can intern'lJy
damage the airbag assembly, making it inoperativo
lf you suspect the airbag assembly has been dam€cd'
inslall a new unit. and relsr lo the Deployment/DisPG'l
olocedules for disposing ol the damaged airbag

How To Use This Manual
The next few pages describe how this manual is organized. They also
explain what kind of information the manual contains, what that
informalion means, and how to use it to troubleshoot electrical problems.
Circuit schematics break the entire electrical system into individual
systems, like the Low Fuel lndicator Light on the nelit page.
Only electrical components that work together are shown together,
so you won't be distracted by unrelated wires.
Explanations of the abbreviations and svmbols used in the schematics
begin on page [Fl. You'll need to know what they mean before you can use
a schematic effectively.

Troubleshooting Tests
Testing for Voltage
When testing for voltage at a connector
without wire seals, you do not have to
seoarate the two halves of the connector.
Instead, probe the connector from the back.
Always check both sides of the connector
because dirty, corroded, and bent terminals
can cause problems (no electrical contact =
an open).
1 . Connect one lead of the test light to a
known good ground, or, if you're using a
digital volt ohmmeter (DVOM), place it in
the appropriate DC volts range, and
connect its negative lead to ground.
Connect the other lead of the test light or
DVOM to the point you want to check.
lf the test light glows, there is voltage
present. lf you're using a DVOM, note the
voltage reading. lt should be within one
volt of measured battery voltage.
A loss of more than one volt indicates
a problem.
NOTE: Always use a DVOM on high
impedance circuits. A test light may not
glow (even with baftery voltage present).
connecthere [fl5tst-tand light should IJJcomeon.
\" I
------{
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lhl
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6m""*soLENo,DI connect here I { lll
I 3#Ji8iL,* lj!!J
Testing for Continuity
When testing for continuity at a connector
without wire seals, you do not have to
separate the two halves of the connector.
lnstead. Drobe the connector Jrom the back.
Always check both sides of the connector
because dirty, conoded, and bent terminals
can cause problems (no electrical contacl =
an open).
1. Disconnect the negative cable from the car
battery. lf you're using a DVOM, place it in
the lowest "OHMS" range.
2. Connect one lead of a self-powered test
light or DVOM to one end of the part of the
circuit vou want lo test.
Connect the other lead to the other end.
lf the self-powered test light glows, there is
continuity. lf you're using a DVOM, a low
reading or no reading (zero), means
good continuity.
.t.
A
r3

Power Distribution
- From Battery to lgnition Switch, Fuses, and Relays
STARTERPage 21,21-1, ot 21-2
.d1.ro"rr" i
I lsoLENorD I
FUSE 42tG1
BATTERY
To UndeFhood ABSFuse/RelayBox onpage 10-14.
FUSE 47EACK UP
T1
FUSE 41AATTEiY&A
I OETECTOR (ELD) UNIT
tii::.':
UO
PHOfO U
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ELECTRICAL LOAD
i--i rL---- J ELKml
!" Gl
FUSE 4e
0ro{ Urod)FUSE '13Ir|]EAtOAUGHT?.:ta
FUSE 46POWEaWll'IDOW
FUSE /t4
r| E/M1{rA204 (DrGa5)
FUS€ 48TtEADL|a}fT9|'A
FUSE 50NEAAOEFOCGER304
+------, f| ',
I ruse sr I oooa I
J LOC|( uNrr \
il-.4WHT/BLK
Itr '\
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c352
vlEW 27
c415Se€ Pow€r Distribution,pag6s 10-10 and 10-11.See Power Distribution,page 10-12.
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L------BLK/VI/HT
1
--------Jc415
Vehiclespre-wired foraccessorysecuritysystem
c913PHOTO 6A
FUSE 16AR DEFFEIAY
FUSE 17HEATEA!'/C FEIAY
FUSE 18{RUNNINOL|GHlFET.AY)7.54
FUSE 27CIGAFETTEL|oHTEAACC SOCKET ta
arse ra fBADIO \
?o?"* \15A ('94 raodcr)
ff".acc0)
llL--------J
See Power Distribution,pages 10-8 and 10-9.
STARTERCUT RELAYPage 21-2
P/lolo 135 (99 00)
See PowetDistribution,page 10-7.
Vehicles pre-wired for acces-sory security system
To Fuse 3'|, for delails, see StartrnqSystem, page 21,21-1 , ot 21-2. -
10

- Automatic Transmission (All except Dl685)
NOTE: For cars equipped with optional security system, see Security System, page 133-3, .133-7, or 133-12
for starting system circuit schomatic.
Starting System
c3s2PHO|O IvlEw 27
ftxiE "2E1404
WHT/BLK
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c415
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9,lLT i ld;f,,"-
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pag€ 10.
slan?(ll)
c415
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Ji.I ELECTRICALI roAoI DETECTOR
I Gt ol ulra Ptfifo I
IJ
BLKAIVHT1
ELK./YEL
au(|vEL
BL'(4I/HT
4
c416PHOTO 53
c4t 6PHO|O 53PHO|O 56 f98 'oo)vtEw t2
c433
Vehiclss pre-wired foraccessory securaty system(Not Used)
R'SE 4IlA??tNY,olALXAVHY'10
Allsxcsptow aLKlvHrcwSoe Pow6r IDistibution, !page 10. a- ----JT1PHOTO 9
BATTERY
BLKAVHT
7
L-----L---JBLKFED
13:;-1ifl;ft?R
!-
)2 'lPHoto tg
a
BLI(RED
1I
ELIVBED
ALKNED
c433PHOTO 76
Soe PowrDslributbn,Pa€o 10.
9 a c101
er.xiwxr I ffo,rtfl't
c4rIPHO|O 63
Ft gg 3r5? F En 3E ^r7.94
4
r'STARTERPHO|O 34UNDER.DASHFUSE/RELAYBOX
A13
tl
II{TEGRATEDco|{TnoLUT{ITPHOfOUvtEw 67,--==--J
Sso PGM-FI, page&1 ot 24-1.
21
lGl

- Automatic Transmission (D1685)
c352
vtEw27
FUSE 42tGtao
.I ELECTRICALI LOADr DETECIOn
| (ELD) uNtrI PHOTO 9
I
UNDER.HOOOFUSE/RELAYBOX
r=-----L-_-_-_-_-_-=_-_-Tl.*1"","1#"Ei]""
li F 3,"j,[',ul
WHT/BLK
. J 9,1'3.WHt a V|EW 14
tcx,^ ) Page 10'
PHOTO 76
1--*---''!N"t- \o3bz7
See PowerDistribution,page 10.
c433
ALKRED4
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Stadorcontrol
POWERTRAINCONTROLMODULE (PCM)
c101
vtEw 28
ll
"'{----1iLi.' | |
Li-gl{l======i---i
"i*-iIr-m'
:il
See PowerDistribdion,Page '10.
".u,"if---'
-,*! s#;:{"
BLKAVHT N V/EW a t
STARTERCUTFELAYPHO|O 129
(99100)
A"/T GEARPOStTtONswrTcH
See PGlr-Fl,page 25.
STARTER
c419
FUSE 31STAffER Src{AI7.54
UNDER-DASHFUSE/NELAYBOX
BLKREO
11
"'-";;tr
A't 3
BATTERY
21-1

- How the Gircuit Works
With the ignition switch in ON (ll) or START (lll),
battery voltage is supplied through fuse 15 and
the BLI(WHT and BLK/YEL wire to the vehicle
speed sensor (VSS). The sensor is grounded by
the BLK wire to G1 01 . The speedometer and
other control units in the circuit supply about 5
volts to the BLU/WHT wire. The vehicle soeed
sensor (VSS) intermittently grounds the
BLUMHT wire which generates a pulsed signal
in it. The number of pulses per minute
increases/decreasos with the soeed of the car.
Reter to th€ Service Manual (Section 23, Electrical)
tor specific tosts or troubleshooting procedures.
33-1

Gruise Control (cont'd)
- How the Circuit Works
The cruise control system uses mechanical and
electrical devices to maintain the car's sDeed at a
setting selected by the driver.
System Description
The cruise control unit receives command signals
from the crurse control main switch and the cruise
control SeVResume switch. With the ignition switch
in ON (ll) or START (lll), voltage is provided to the
cruise control main switch through fuse 14. When
you push the switch to ON, power is provided to the
cruise control unit and the brake switch.
The cruise control unit receives information about
operating conditions from the brake switch, the
vehicle speed sensor (VSS), and the clutch switch
(manual transmission) or the A,/T gear position
switch (automatic transmission). The cruise control
unit then sends signals to the cruise control actuator
which regulates the throttle position to maintain the
selected speed. The conlrol unit compares the
actual speed of the car to the selected speed. The
control unit then uses the result of that comoarison
to open or close the throttle.
The brake switch releases the system's control of
the throttle at the instant you press on the brake
pedal. The switch sends a signal to the control unit
by removing power from the normally closed brake
input (GRY wire), and providing power at the
normally open brake input (GRN/vVHT wire). The
control unit responds by allowing the throttle to
close. The clutch switch or the A,/T gear position
switch sends a "disengage" signal to the control unit
that also allows the throttle to close.
The cruise control system will set and automatically
maintain any speed above 25 mph (40 km/h). To set
it, make sure the main switch is on and the switch
indicator is on. Then, after reaching the desired
speed, press the SET switch. This sends a "set"
signal to the cruise control unit which, in turn,
controls the cruise control actuator to maintain the
set speed.
When you push the SET switch and the cruise
control system is on, the "cruise control" ON
indicator lights up.
34-4
(
You can cancel the cruise control system by
turning the main switch off . This removes power to
the control unit and erases the set speed from
memory. lf the system is disengaged temporarily
by the brake switch, or clutch switch, and the car's
speed is still above 25 mph, press the resume
switch: the car will automatically return to the
previously set speed.
For gradual acceleration without pressing the
accelerator pedal, push the RESUME switch and
hold it there. This will send an "acceleration" signal
to the control unit. When you release the switch, the
system will be reprogrammed for the new speed. To
slow the car down. oush the SET switch in and hold
it there. This sends a "deceleration" signal to the
control unit, causing the car to coast. When the
desired speed is reached, release the SET switch.
This reprograms the system tor the new speed.
Refer to the Service Manual (Section 23, Electrical)
tor specific tests or troubleshooting procedures.
(
a