1999 HONDA CIVIC Ignition switch

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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How the Circuit Works
Seat Belt Warning
With the ignition switch in ON (ll) or START (lll),
battery voltage is applied to the seat belt reminder
light. When the seat belt is not buckled, the seat
belt reminder/key-on beeper circuit in the
integrated control unit senses ground through the
closed seat belt switch. The seat belt reminder light
comes on and stays on, and the beeper beeps for
6 seconds. The reminder light and beeper will stop
when the seat belt is buckled or the timer circuit
deactivates them.
lgnition Key Warning
Battery voltage is supplied at all times to the seat
belt reminder/key-on beeper circuit in the
integrated control unit. When you turn on the
ignition key switch the integrated control unit
senses ground. lf you open the driver's door, the
door switch closes, causing the beeper to sound
until the door is closed.
Refer to the Service Manual (Section 23, Electrical)
for specitic tests or troubleshootrng procedures.
73-1

Gauges (cont'd)
- How the Gircuit Works
When the ignition switch is in ON (ll) or START (lll),
battery voltage is supplied through fuse 25 to the
gauges in the gauge assembly.
Speedometer and Odometer
The odometer and soeedometer drive circuits
receive pulses from the vehicle speed sensor
(VSS). The pulse rate increases as the car
accelerates. The frequency and duration of these
input pulses are measured and displayed by the
speedometer, odometer and tripmeter.
Tachometer
The tachometer drive circuit receives pulses from
the ignition control module (lCM) in the distributor
assembly or the ECM/PCM. The solid-state
lachometer then displays these pulses as engine
speed. For each 200 pulses per minute from the
ignition control modul€ (lCM) or the ECM/PCM, the
tachometer displays 100 RPM.
Engine Coolant Temperature Gauge
The engine coolant temperature gauge has two
intersecting coils wound around a permanent
magnet rotor. Voltage applied to the coils, through
fuse 25, generates a magnetic lield. The magnetic
field, controlled by the coolant temperature sending
unit, causes the rotor to rotate and the gauge
needle to move. As the resistance in the sending
unit varies, current through the gauge coils
changes. The gauge needle moves toward the coil
with the strongest magnetic field.
The 6ngine coolant temperature sending unit's
resistance varies from about 137 ohms at low
engine temperature to between 3H6 ohms at high
temperature (radiator fan running).
Refer to the Service Manual (Section 23, Electrical)
for specific tests or troubleshooting procedures.
81-2
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Fuel Gauge (All except cX)
The fuel gauge has two intersecting coils wound
around a permanent magnet rotor. Voltage applied
to the coils, through tuse 25, generates a magnetic
field. The magnetic field, controlled by the fuel
gauge sending unit, causes the rotor to rotate and
the gauge needle to move. As the resislance in the
sending unit varies, current through the gauge coils
changes. The gauge needle moves toward the coil
with the strongest magnetic field.
The fuel gauge sending unit's resistance varies
from about 2-5 ohms at full, to about 110 ohms at
empty. When you turn the ignition switch off, the
gauge remains at the last reading until you turn the
ignition switch to ON (ll) or START (lll) again,
Refer to the Service Manual (Section 23, Electrical)
for specific tests or troubleshooting procedures.
Fuel Gauge (GX)
The fuel gauge has two intersecting coils wound
around a permanent magnet rotor. Voltage applied
to the coils, through fuse 25, generates a magnetic
field. The magnetic field, controlled by the PCM,
causes the rotor to rotate and the gauge needle to
move. The PCM calculates the gas quantity in the
fuel tank by using the fuel pressure value detected
by the tuel tank pressure sensor and the fuel
temperature value detected by the fuel tank
temperalure sensor, and outputs the signal to the
gauge assembly. The gauge needle moves toward
the coil with the strongest magnetic field.
When you turn the ignition switch off , the gauge
remains at the last reading until you turn the ignition
switch to ON (ll) or START (lll) again. When the
PCM detects a malfunction with the fuel pressure or
temperature, or detects a gas leak, the PCM
reduces the fuel meter to 0.
Refer to the Service Manual GX Supplement
(Section 11 , Fuel and Emissions) for specific tests
or troubleshooting procedures.
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A/T Gear Position Indicator (conrd)
- How the Circuit Works
With the ignition switch in ON (ll) or START (lll),
voltage is applied to the A,/T gear position indicator.
The A,/T gear position switch provides a ground for
each position. As an input is grounded, its indicator
light comes on. lf you select R, for example, ground
will be provided to the input of the A,/T gear position
indicato( and the R indicator will come on.
With the headlight switch in PARK or HEAD, voltage
is applied to the RED/BLK wire terminal. This
changes the indicator panel illumination from fixed
to controlled by the dash lights dimmer input
through the RED wire.
When the powertrain (all except '96-'98 CVT) or
transmission ('96198 CVT) control module (PCM or
TCM) detects an abnormality in the automatic
transmission control system, or when you request
diagnostic trouble codes through the service check
connector, the PCM or TCM will make the D4 (D for
CVT) indicator light blink.
Refer to the Service Manual (Section 14,
Automatic Transmission) for specific tests or
troubleshooting procedures.
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89-2

Front WiperMasher (cont'd)
- How the Circuit Works
When the ignition switch is in ON (ll) or START (lll),
battery voltage is applied to lhe combination wiper
switch. and the windshield wiDer motor.
Low Speed
When you turn the wiper switch to LO, the wiper
motor's low speed winding is grounded through the
BLU wire and the LO speed contacts of the wip€r
switch at G401, and the wipers run at low speed.
ParUOfl
When you turn the wiper switch OFF, the integrated
control unit (PARK input) grounds the wiper motor
through the BLUMHT wire. The cam switch on the
motor signals the integrated control unit that the
wipers are in the PARK position; the control unit
then removes ground from the motor, and the
wipers stop in the PARK position.
High Speed
When the wiper switch is in Hl, the high speed
windings of the windshield wiper motor are
grounded through the BLUIrEL wire and the Hl
contacts of the wiper switch at G401, and the
wipers run at high speed.
Intermittent
When the wiper switch is in lNT, battery voltage is
applied through the YEUBLU wire to the integrated
control unit (lntermittent wiper ON input). The
integrated control unit (lnt€rmittenvPark Wiper
Control) grounds the low speed windings of the
wiper motor and the wipers make a single sweep
every few seconds (See Low Speed above). When
the wiper retums to the PARK position, the park
switch applies battery voltage through the
BLUMHT wire to the integrated control unit (PARK
input), and the wipers stop in the PARK position.
Mist
When you pull the wiper switch down to MIST
position, the high speed windings ot the wiper motor
are grounded through the BLU^/EL wire and the
closed contacts ot the mist switch at G401, and the
wipers make one pass across the windshield at high
speed. The ParUOff function then takes over and
the wipers stop in the PARK position.
Washel
When you pull the wiper switch toward you to turn
on the washer switch, battery vollage is applied to
the washer motor. The motor pumps fluid onto the
windshield until you release the lever; on '98r99
models, the integrated control unit (windshield
washer ON input) s€nses power at the WHT/BLK
wire terminal and runs the wipers whenever the
washer motor runs.
Refer lo the Service Manual (Seclion 23, Electrical)
for specific tests or troubleshooting procedures.
91-2

Headlights (cont'd)
- How the Circuit Works
Low Beams
With the headlight switch in HEAD and the dimmer
switch in LO, current tlows through the headlight
switch. fuse 21 . fuse 22. and the low beam
tilaments to ground, and the low beams come on.
High Beams
With the headlight switch in HEAD and the dimmer
switch in Hl, current flows through the headlight
switch, dimmer switch, fuses 4, 5, and the high
beam filaments to ground, and the high beams
come on.
Current also llows through the high beam indicator
light to ground. The high beam indicator comes on
to remind the driver that the high beams are on.
Flash-to-Pass
The flash feature works with the headlight switch in
OFF, PARK, or HEAD (low beams). When you move
the flash-to-pass switch to ON, current flows
through the switch, fuses 4 and 5, and the high
beam filaments to ground, and the high beams
flash. The high beam indicator also flashes during
the flash operation. The flash function has no effect
if the high beams are already on
Daytime Running Lights (Canada)
When you turn the ignition to ON (ll) with the
parking brake released, the daytime running lights
control unit supplies battery voltage at the
WHT/RED wire. This voltage is applied to the high
beam headlights through the daytime running lights
resistor. Each high beam headlight receives less
than battery voltage causing them to come on at
reduced brightness.
lf the parking brake is set, a ground signal is applied
to the daytime running lights control unit at the
RED/GRN wire. lf the parking brake is set when you
first turn the ignition switch to ON (ll), the high beam
headlights will remain off until you release the
parking brake. Once the high beam headlights are
on, setting the parking brake will not turn them ofi.
When low or high beam operation is requested,
battery voltage from the headlight switch is applied
to the daytime running light control unit via the RED
wire. The daytime running lights control unit then
turns off the headlights.
Refer to the Service Manual (Section 23, Electrical)
for specific tests or lroubleshootrng procedures.
110-14

Power Windows (contd)
- How the Circuit Works
CAUTION: You could iniure your arms, hands, or
fingers if you unintentionally switch the driver's
window to "automatic down" while working in
that door with the power on. Disconnect the
window switch conneclot or the battery when
working in the driver's door.
System Description
The operation of the power windows is controlled by
the main switch in the power window master switch.
When the main switch is in OFF, only the driver's door
window can be opened or closed. With the main
switch ON, all windows can be ooened or closed
either by swtches in the master panel, or swttches in
the doors. The driver's window switch also has an
automatic down mode which is tumed on by pushing
the switch down to its second oosition.
The power windows are driven by reversible motors.
Each motor is protect€d by a built-in circuit breaker.
lf the window switch is held on too long (with the
window obstructed, or after the window is fully up or
down), the circuit breaker opens the circuit. The
circuit breaker resets automaticallv as it cools.
Driver's Window
With the ignition switch in ON, voltage is provided to
the coil of the power window relay through fus€ 24.
The contacts of the power window relay close, and
voltage is applied to the driver's switch. When you
push the power window master switch to UP, voltage
is applied to the driver's window motor. (The motor's
ground path is back through the master power
window switch.) The driver's window motor then
drives the window up. When you push the switch to
DOWN, voltage is applied in the opposite direction
and the motor drives the window down.
Automatic Down (Driver's Window)
With the ignition switch in ON or START, voltage is
applied to the coil of the power window relay. The
contacts of the power window relay close and
voltage is applied lo the power window master
switch. When you push the driveas switch to the
AUTO DOWN position, voltage is applied through
the driver's switch to the driver's window motor. The
control unit receives pulses at the pulser input while
the motor is running. When the window is fully
down, the motor stops, and pulses are no longer
generated by the pulser. This is sensed by the
control unit at the pulser input, and voltage is no
longer applied to the driver's window motor.
Passenger Windows
With the ignition switch in ON, voltage is applied to
the coil of the power window relay through fuse 24.
The contacts of the power window relay then close,
applying voltage to the individual window switches
and the power window master switch. With the
master panel main switch ON, the passenger
windows can be ooerated from the individual
window switches or from tho master panel switches.
When you push the front passengsr's window
switch to UP, voltage is applied to the f ront
passenger's window motor. (The motor is grounded
through the contacts in the front passenger's
window switch and the oower window master
switch.) The window moves up as long as you hold
the switch in the UP position. lf you push the switch
to DOWN, voltage is applied in th€ opposite
direction to the front passenger's window motor, and
the window movss down as long as you hold the
switch in the DOWN Dosition. The window switches
in the other doors operate similarly.
When you push the front passenger's switch in the
master panel to UP, voltage is applied through the
front passenger's window switch contacts to the
front passengefs window motor. (The motor is
grounded through the contacts in the front
passenger's window switch and the power window
master switch.) The window moves up as long as
you hold the switch in the UP position. lf you push
the switch to DOWN, voltage is applied in the
opposite direction to lhe front passenger's window
motor, and the window moves down as long as you
hold the switch in the DOWN position. The other
passenger window switches in the master panel
operate similarly.
Refer to the Service Manual (Section 23, Electrical)
for specific tests or troubleshooting procedures.
120-4

Power Door Locks (cont'd)
- How the Circuit Works
Keyless Entry System
The keyless door locks combine the power door
locks with a remote keyJob transmitter. The keyless
receiver unit is part of the radio. The keyless
receiver unit receives direct inputs f rom the ignition
key switch, the passenger door switches, and an
indirect input trom the driver's door switch through
the integrated control unit.
Power Door Locks (With or Wlthout Keyless)
The power door lock system is made up of the
oower door lock control unit. driver's door lock
switch, and individual door lock actuators. The
power door locks are controlled by the driver's door
lock switch and the driver's door lock actuator
switch.
Transmitter (With Keyless Entry)
The transmitter sends coded radio wave signals to
the keyless receiver unit when one ot its buttons is
pressed. Each transmitter has a unique code that
must be 'laught" to the keyless receiver unit before
it can operate the door locks or any other lunction.
Up to 4 transmitters can be programmed to operate
the keyless door locks.
Door Locking (With or without Keyless Entry)
When you push the driver's door lock switch to the
lock position, ground is applied to the GBN/IVHT
wire to the oower door lock control unit. The control
unit then applies battery voltage to the WHT/RED
wire and ground to the YEURED wire. The
passenger door lock actuators then activate to lock
the corresponding door locks.
When you lock the driver's door with the key or door
lock knob, it is mechanically locked, and the driver's
door lock actuator switch applies ground to the
oower door lock control unit. The control unit then
applies battery voltage to the WHT/RED wire and
ground to the YEURED wire, activating the
passenger door lock actuators which lock the doors.
Dool Locking with Transmitter
When you press the LOCK button on the remote
transmitter, the power door lock control unit applies
battery voltage to the WHT/RED wire and ground to
the YEURED wire. The passenger door lock
actuators then activate and lock the doors. A ground
slgnal is also applied to the BLU/RED wire to lock
the driver's door. lf any door is open, you cannot lock
it using the remote transmitter.
Door Unlocking (With or Without Keyless Entry)
When you push the driver's power door lock switch
to the unlock position, ground is applied to the
GRN/ORN wire to the power door lock control unit.
The control unit then applies battery voltage to the
YEURED and BLU/RED wires and ground to the
WHT/RED wire. The door lock actuators then
activate to unlock the doors.
When you unlock the driver's door with the key or
the door lock knob, it is mechanically unlocked; the
other doors do not unlock.
Door Unlocking (With Transmltter)
When you press the UNLOCK button on lhe remote
transmitter once. the power door lock control unit
applies battery voltage to the WHT/RED wire and
ground to the BLU/RED wire to unlock the driver's
door. When you press the UNLOCK button twice,
the control unit then applies ground to the YEURED
wires to activate the passenger door locks. lf you do
not open a door within 30 seconds after unlocking
the doors with the transmitter, the doors
automatically relock.
Transmltter Programming
1 . Turn the ignition switch ON (ll).
2. Press and hold the Valet-Disarm button on the
radio (between the AM/FM button and the
CD/TAPE button) to enter the programming
mode. (Continue to hold the button during the
procedure, or programming will be cancelled.)
Check that the power door locks cycle to confirm
that you're in the programming mode.
3. Press the "LOCK' or "UNLOCK' button on the
transmitter. Check that the power door locks
cycle to confirm that the code was accepted.
4. Press the "LOCK" or "UNLOCK" button on each
of the remaining transmitters. (You can program
up to four transmitters per vehicle.)
5. After all the transmitters have been
programmed, release lhe Valet-Disarm button to
exit the programming mode.
Beep On/Oft Feature
'I . Press and hold the LOCK and OPTION buttons
on the transmitter.
2. Watch the transmitter's LED:
One flash: Beeo activated.
Two tlashes: Beeo deactivated.
130-4