1997 HONDA CIVIC Electrical troubleshooting

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Electrical
Special Toofs .,....................,23-2
Troubleshooting
Tips and Precautions ..............,.................... . 23-3
Five-step Troubleshooting .............. ......... . . 23-5
wire color codes ..........,23-5
Schematic Symbols ........,................... . . .. .... 23-6
Relay and Control Unit Locations
Engine Compartment ...,..................... ... .. . 23'7
Dashboard ......................23-8
Dashboard/Door ......... 23-12*Airbags ................. ....... Section 24
Air Conditioning ......... Section 21
Aftelnator ..........."""" """ 23-112
Anti-lock Brake System {ABS) Section 19*A/T Gear Position Indicator .....................,. .... ... 23-149
Automatic Transmission Svstem .... . ....... Section 14
Batterv ......... . . . ... ...... .......23-91
Blower controls .. . ... Section 2l
Charging System ....'...........23'112
Connector ldentilication and Wire Harness
Routing .................. ......23'13
Cruise Control ............,........23-240
Dash Lights Brightness Controller ............. ....... 23-180
Fan controfs "" 23'126
Fuel PumD ........ . ........ section 11
Fuses/Refay ...............,..,,.. 23'62
PGM-FI Control System ......................,....... Section 1 1
*Gauges
Circuit Diagram ....,.,.......23-131
Fuef Gauge ...........'.'.......23-142
Gauge/lndicator .. . .. 23-129
Ground Distribution .. . 23-75
Heatei controls .. . ..... Section 21*Horn................. ...............23-196
*tgnition Switch ....................23-89
lgnition System .......,.... 23-102
*lntegrated Control Unit ....................................... 23-156
fnterlock System ,........ . . , ,23-144
Lighting System . . . .. ......... 23-161
Lights, Exterior
Back-up Lights ..'............23'171
Brake Lights .................. 23'174
Daytime Bunning Lights (Canadal ............... 23'166
Front Parking Lights ......,................ .'. .......... 23-167
Front Turn Signal Lights .......... . . ............ ..,.23-167
Headtights ....".'....-... ..... 23'167
High Mount Brake Light ...................... ... .23'179
License Plate Lights ...... 23'176
Taitfights ................ .......23'171
lnterior Lights ..-.......,, . 23-142
Moonroof ..,.................,........ 23-235
Power Distribution ....... . . .23-61
Power Door Locks .......,,,. .23'251
Power Mirrors ,..............,.,...23'206
Power Relays ....... . ...... . . .. 23-86
Power Windows ............,,....23-220
Rear Window Defogger .......................... . . ... . . 23-2OO
Spark Plugs . ..... . ........ .....23-111
Slarting System ................23-93*stereo Sound Svstem ,................. ..... ... . ... ,.,.,,23'147'Supplemental Restraint System (SRS) ... . Section 24
Turn Signal/Hazard Flasher System .......'.'....-... 23-173
*Undel-dash Fuse/Relay Box ............,.................. 23-85
vehicfe soeed sensor (VSSI """" ""' 23-140+Wipers/Washers .........,.,.,...23-214
NOTE: Unless otherwise specified, references to auto-
matic transmission (Mf) in this section include the CVT.

Troubleshooting
Tips and Precautions (cont'dl
Insert the connector all the way and make sure it is
securelv locked.
Position wires so that the open end of the cover faces
down.
After installing harness clips, make sure the harness
doesn't interfere with any moving pans.
Keep wire harnesses away from exhaust pipes and
other hot parts. from sharp edges of brackets and
holes, and from exDosed screws and bolts.
V
F6c6op€n end
Handling Wires and Harnosscs
. Secure wires and wire harnesses to the frame with
their respective wire ties at the designated locations,
. Remove clips carefully; don't damage their locks.
Slip pliers under the clip base and through the hole at
an angle, then squeeze the expansion tabs to release the
clrp.
SNAP-BING PLIERS
23-4
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Testing and Repairs
o Do not use wires or harnesses with broken insulation.
Replace them or repair them by wrspping the break
with electricaltaoe.
. After installing parts, make sure that no wires arepinched under them.. When using electrical test equipment, follow the
manufacturer's instructions and those described in
this manual.
. lf possible, insert the probe of the tester from the
wire side (except waterproof connector).
. Seat grommets in their grooves properly.
. Use a probe with a tapered tip.
Refer to the instructions in the Honda Terminal Kit for
identification and replacement of connector termi-
nats.

Charging System
Component Location Index
UNDER.HOOD FUSE/RELAY BOX/*Has replaceable ELECTRICAL LOAD II DETECTOR (ELD) UNIT '
Troubleshooting, page 23-1 14Replacement, page 23-120Bectifier Removal, page 23,121Rectifier Test, page 23-122Rear Bearing Replacement, page 23-j24
*ELD unit: USA
CHARGING SYSTEM LIGHT(ln the gauge assembly)Test, page 23- l14
BATTERYTest, page 23-91
ALTERNATOR BELTInspection and Adjustment, page 23-t25
[]
23-112

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.
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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.
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- 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
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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.
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Rear Window Defogger
- How the Circuit Works
'96198 Models
Voltage is applied at all limes through tuse 50 to the
rear window detogger relay (contacts). With the
ignition switch in ON (ll), voltage is applied through
tuse 16 to the rear window defogger switch.
When you turn the switch ON, voltage is applied to
the defogger timer circuit. The timer circuit supplies
voltage to the rear window defogger relay (coil). The
relay energizes and supplies voltage to the rear
window defogger. The defogger grid then heats the
rear window to remove any condensation from the
glass.
The defogger timer circuit will automatically turn off
the rear window defogger after about 25 minutes.
Refer to the Service Manual (Section 23, Electrical)
for specific tests or troubleshooting procedures.
'99100 Models
Voltage is applied at all times through fuse 50 to the
rear window delogger relay (contacts). With lhe
ignition switch in ON (ll), voltage is applied through
fuse 16 to the heater control oanel.
When you turn the rear window defogger switch
ON, a signal is sent to lhe defogger timer circuit
built-into the heater control oanel. The timer circuit
supplies voltage to the rear window defogger relay
(coil). The relay energizes and supplies voltage to
the rear window defogger. The defogger grid then
heats the rear window to remove anv condensation
from the glass.
The defogger timer circuit will automatically turn otf
the rear window defogger after about 25 minutes.
Refer to the Seryice Manual (Section 23, Electrical)
for specific tesls or troubleshooting procedures.
64-2
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Brake System Indicator Light (cont'd)
- How the Circuit Works
The brake system indicator light comes on to alert
the driver that the parking brake is applied, or that
the brake fluid level is low. lt also comes on as a
bulb test when the engine is cranked.
Parking Brake
With the ignition switch in ON (ll) or START (lll),
voltage is applied through fuse 25 to the brake
system light. When you apply the parking brake, the
switch closes and provides a ground for the light.
The light then comes on to remind you that the
parking brake is applied.
Brake Fluid Level
With the ignition switch in ON (ll) or START (lll),
voltage is applied through fuse 25 to the brake
system light. lf the brake fluid level is low, the brake
fluid level switch closes, providing ground to the
circuit. The brake system light then comes on,
alerting the d verto a low brake fluid level in the
brake master cylinder. (Check brake pad wear
before you add fluid).
Bulb Check
With the ignition switch in START (lll) and clutch
pedal depressed or A'lT gear selector in PARK (P)
or NEUTRAL (N), voltage is applied through fuse 31
to the brake bulb check circuit. The brake bulb
check circuit closes, allowing current to flow through
the brake system light and bulb check circuit to
ground. The brake system light then comes on to
test the bulb.
Refer to the Service Manual (Section 23, Electrical)
for specific tests or troubleshooting procedures.
71-2
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