2000 HONDA CIVIC Ignition

How To Use This Manual
Symbols
Ground - "G"
This symbol means the end ol
the wire is attached (grounded) Ito the car frame or to a metal I
part connected to the frame. \i oro,|
-t'
Each wire ground (G) it --/
numbered for reference.
oo
Switches
These switches move
together; the broken straight
line between them means the,
are mechanically connected.
Other types of switches are
controlled by a coil or a solid
state circuit. Unless otherwise
noted. all switches are shown
in their normal (rest) position,
with power off.
This ground symbol (dot
and 3 lines) overlapping the
component means the housing
of the component is grounded
to the car frame or to a metal
part connected to the frame.
This symbol represents
the bus inside a ground
connector. The dots I
i:l*,':1,'^:*,:"
;"
r"L I I I
terminals connect to.
The ground symbol (large dot)
is the connection between the
bus and metal (grounded) part
of the car.
Terminals - "T"
ffi
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Solid-state
Fuses
This means power is supplied
when the ignition switch is in ON (ll).
Current rating
Diodes
A rectifier diode works like a one
way valve. lt allows current to
llow only in the direction of the
arrow.
A Zener diode blocks reverse
current at normal voltages just like
a rectifier diode. At high voltages.
however, a Zener diode allows
current to f low in reverse
oo
Each "T" lerminal (ring type)
is numbered for reference and
location. A "T" terminal is
secured with a screw or bolt.
Shielding
This represents RFI
(Radio Frequency
Interference) shielding
around a wire. The
shielding is always
connected to ground.
f--l;j-i",..
I
,,,,
T

How To Use This Manual
Troubleshooting Tests
Testing for Voltage Drop
Wires, connectors, and switches are designed
to conduct current wilh a minimum loss of
voltage. A voltage drop of more than one volt
indicates a Droblem.
'1. Place the digital volVohmmeter (DVOM) in
the appropriate DC volts range. Connect
the positive lead to the end of the wire
(or to the connector or switch) closest to
the bafterv.
Connect the negative lead to the other
end of the wire (or the other side of the
connector or switch).
Turn on the components in the circuit.
The DVOM will show the difference
in voltage between the two points. A
difference, or drop, of more than one
volt indicates a oroblem. Check the
circuit for loose, dirty, or bent terminals.
co
Testing lor a Short with a Test Light or DVOM
1. Remove the blown fuse and disconnect
the load.
2. Connect a test light or digital
oltr'ohmmeter
(DVOM), switched to the appropnare DC
volts range, across the tuse lerminals to
make sure voltage is present. You might
have to turn the ignition switch to ON:
check the schematic to see.
<-s80RT TOGFOUNO
Disconnecl lheload here.
Beginning near the luse box, wiggle the
harness. Continue this at convenient ooints
about six inches apart while watching the
test light or DVOM.
Where the test light goes off, or the DVOM
voltage drops to zero, there is a short to
ground in the wiring near that point.
NOTE: Always use a DVOM on high
impedance circuits. A test light may not
glow (even with battery voltage present).
3''
ffito.'"o'o
.t.
TEST LIGHTolDVOM

Fuse/Relay Information
- Under-dash Fuse/Relay Box
Front View
c712(To moonroof wire harness)
. : Canadai : Not UsedO : C926 loprion (+B)l
@ : C927 loption (dash lights)]
O : C928 [Option (ACC]I
@ : C929 loption (lc2)l
Rear View
css2
c421(To main wire harness)
c801CI-o SRS main harness)
c501(To dashboard wire harness)
^ : Not used ('96-'97 models)
c913(To ignition switch)
INTEGRATEDCONTROL UNITCONNECTOR A
c419Oo main wire harness)
REAR WINDOWDEFOGGER RELAY
TURN SIGNAUHAZARD RELAY
c423(To main wire harness)
co
c422(To main wire harness)
POWERwtNDowRELAY
c551flo lloor wire harness)c439 f96.'97 MODELSand ALL GX MOOELS)(To main wire harness)
T1 T-t T"l T"t r-r r-'l T1 F n r-l r-l r'123 24 25 26 27 28 29 30 31 32 33I-J I.J I.J IJ IJ IJ LJ IJ IJ I.J I.J I-I
r"1 r-t r-t T-l r"l r-r Fl r:1 n rJ n -12 13 14 t5 16 17 t8 19 2A 2t 22LI I.J L! LI tJ LJ (J LI IJ IJ T-I I.J
n r:l rj.l |-l T"l Tl r:t n r-l |;.l r-r r-l1 2 3 4 5 6 7 I 9 10 11LI LI IJ LJ LJ I,J T-I I.J TJ IJ I.-I tJ
c420(To main wire harness)
6
(To floor wire harness)

PGM-FI (D1685) (cont'd)
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POWERTRAINCONTROLMODULE (PCM)
c9 A C30
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25-2

- 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

- How the Circuit Works
The anti-lock brake system (ABS) prevents locking
of the wheels as a result of heavy braking and/or
poor lraction. A vehicle with locked wheels cannot
be steered. The anti-lock brake system controls the
application of the brakes, allowing the driver to
maintain control of the steering.
Under anti-lock conditions, the antilock brake
system (ABS) modulates the pressure of the brake
tluid to each brake caliper. This system is a four
channel system: the pressure at each caliper is
controlled independently of the pressure al any
other caliper. Whenever a wheel is likely to lock
dunng braking, the anti-lock brake system
modulates the brake oressure at that wheel. When
the brake pressure is reduced to the point where
there is no longer any possibility of wheel locking,
the system returns to the conventional braking
system mode of operation.
Battery voltage is applied at all times through fuse
63 to the ABS control unit. When the ignition switch
is in ON (ll), battery voltage is supplied to the
control unit through fuse 16. The control unit is case
grounded. Inputs are received from the brake switch
and the individual wheel sensors located at each
wheel. The ABS control unit uses these inputs to
control the modulator solenoid unit. The solenoids
adjust the hydraulic pressure applied to each
calioer.
The ABS control unit has a self-diagnosis function.
When the control unit detects a fault, it turns on the"ABS" indicator and disables the anti-lock brake
system. lf the fault is not in the conventional braking
system, the brakes will continue to operate normally
but without the anti-lock feature.
Refer to the Service Manual (Section '19,
Anti-Lock Brake System) for specific tests or
troubleshooting procedures.
44-3