1998 HONDA CIVIC Trouble shooting ignition system

Troubleshooting
DTC 1-5
CAUTION: Whenever the ignition switch is ON {ll). or
has been turned OFF for less than three minutes, be
caretul not to bump ths SRS unit; the airbag(sl could
accidentally deploy and cause damage or iniuries.
J
DRIVER'S AIRBAG2P CONNECTOR
SRS MAIN HARNESS2P CONNECTOR
DRIVER'S AIRBAGASSEMBLY
REEL
07sAz - TB40't1A(2 0 JACK)
2P CONNECTOR
AZ - SZ5011A
CABLEREEL2P CONNECTOR
I
07TAZ - SZ5011A
Try to rep.oduce the SRS indicator light:1. Erasethe DTC memorv (See page 24'15).2. Turn the ignition switch ON (ll), and check that the SRS indicator light comes on tor about six seconds and goes off.
Ooes the SRS indicator light stay onl
YESNO
Intermittent lailure, system is OK at this time. See Trouble-shooting lntormittent Failure3 on page 24-15.
Check for a short to ground in lh€ driver's airbag inllator:1. Turn the ignition switch OFF.2. Disconnect the battery negative cable, then disconnectthe positive cable, and wait for three rninutes.3. Disconnect the driver's airbag 2P connector from thecable reel 2P connector.CAUTION: Do not disconnect tho p.ssenger's airbagconnectoa.4. Connect the specialtool (2 0)to the cable reel 2P connector.5. Reconnect the batlery positive cable, then reconnect thenegative cable-6. Erase the DTC memory (see page 24-15).7. Read the DTC (see page 24-131.
ls OTC 1-5 indicatedT
YESNO
Short to ground in the drive/s airbeg inflator; r€pl.ce thedriver's.iib.g (see page 24d1.
Check lor a short to ground in the csble reer:l. Disconnect the battery negative cable, then disconnectthe positive cable, and wait for three minutes.2. Disconnect the special tool {2 (}) from the cable reel 2P
3. Remove the dashboard lower cover, and disconnect thecable reel 2P connector from the SRS main harness.4. Connect the Special tool {2 0} to the SRS main harness2P connector (cont'd).
To page 24-49
{2 0 JACK)
24-44
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Troubleshooting
DTC 2-1 and DTC 2-2 - Wathout Front Passenger's Airbag
CAUTION: Whenever the ignition switch is ON {lll. or
has been turned OFF tor less than three minutes, be
caretul not to bump the SRS unit; the aidag could acci-dentally deploy and causs damage or iniuries.
Try to reproduc€ the SRS indicator light:1. Erase the DTC memory {see page 24-15r.2. Turn the ignition switch ON (ll), and check thatthe SRS indicator light comes on lor about six seconds and ooes off.SRS UNIT
Intermittent failu.e, system is OK at this time. Se€ Trouble-Intermifient Failuies on paqe 24-15.
OUMMY RESISTOR
Check for an open oa increased resistance in the dummvteslstot:1. Turn the ignition switch OFF.2. Remove the dummy resistor from the SRS main harness2P connector,3. Check the resistance between the A and B terminals ofthe dummy resistor. There should be 1.5 - 2.5 0.
resistoa.
Check lor an open or incre.sed resisiance in the SRS mainharness:'1. Disconnect the battery negative cable, then disconnectthe positive cable, and wait for three minutes.2. Disconnect the driver's airbag 2P connector from thecable reel2P connector lsee page 24 t t).3. Disconnect the SRS main harness t8p connector fromthe SBS unit.4. Connect the dummy resistor to the SRS main harness 2pconnector.5. Check resistance between the No- 1O terminal and No. 14terminal of the SRS main harness 18p connector. Thereshould be aDorox. 1.5 - 2.5 0.
SRS MAIN HARNESS18P CONNECTOR
ls the resistance es speciti€d?
YES
Poor contact ar the SRS main hahess 18p connector;check the connector.. lf the connector is OK. substitute a known-good SRSunit, and recheck.. lf the problem is still present. repbce the SRS mainnarness.
24-5A
\
Ooes the SRS indicalor light stay on?
Open or increased resi3tanc6 in tho SRS main harness;OU
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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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- 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

- How the Circuit Works
'96198 Models
The air delivery system directs the flow of air used
by the heater and air conditioner systems.
Mode Selection
Mode selection is controlled by the mode switches
in the heater control panel and the mode control
motor. When you select a specific mode, voltage is
applied through the dimming circuit to the LED,
which comes on, indicating the mode selected.
Ground is orovided to the mode control motor
though that mode switch. The motor then runs until
the air control door reaches the proper position.
Fresh/Recirculation 56lection
When you press the fresh or recirculation button, a
ground signal is sent from the heater control panel
to the recirculation control motor. The motor then
runs until the recirculation door reaches the proper
position. Battery voltage is also applied through the
dimming circuit to the corresponding LED, and the
LED comes on.
Refer to the Service Manual (Section 21, Heater) for
specitic tests or troubleshooting proc€dures.
'99J00 Models
The heater control panel receives battery voltage at
all times through fuse 47. With the ignition switch in
ON (ll), voltage is supplied to the heater control
panel through fuse 17. The control panel is
grounded at G402.
The heater control panel controls the air delivery
motors, and supplies a 5 VDC reterence voltage to
the air mixture control motor.
The air mixture and mode control motors each
receive inputs trom the heater control panel. The air
mix motor regulates the mixture of cold and hot air
by varying the position of the heater-evaporator doot
The mode control motor controls the direction and
volume of outlet air. The air flow can be directed to
the dashboard vents or the corner vents.
Both the air mixture control molor and mode control
motor are grounded by the h€aler control panel.
The recirculation control motor receives battery
voltage through fuso 17 when the ignition swilch is
in ON (ll). lt regulates the position of the fresh/recirc
door, and is controlled by two position inputs from
the heater control panel ("Recirc" and "Fresh").
Refer to the Service Manual (Section 21, Heater) tor
specific tests or troubleshooting procedures.
61-3

- How the Circuit Works
Battery voltage is supplied through tuse 56 to the
A,/C compressor clutch r€lay contacts at all times.
With the ignition switch in ON (ll), vollage is applied
to the coil of the A,/C compressor clutch relay
through fuse 17. When you push the A,/C switch
ON, and the heater fan switch is in position | , 2, 3,
or 4, a "ground" input is provided to the engine
control module (ECM) or powertrain control module
(PCM) through the l'lC thermostat and the l'lC
pressure switch.
The A,/C compressor clutch relay is grounded by the
engine control module (ECM) or powertrain control
module (PCM). When energized, the A'lC
compressor clutch relay allows battery voltage to
turn on the A,/C comDressor clutch.
The A,/C ON indicator light comes on when the A,/C
system is requested.
A,/C Thermostat
The A'lC thermostat is located on the evaoorator
housing. The A,/C thermostat turns off the A,/C
compressor clutch if the temperature at the
evaporator goes below 3'C (37'F). This prevents
condensation from freezing on the evaporator fins
and blocking the air delivery into the passenger
compartment. The blower motor will keep running
when the sensor turns off the comDressor.
A,/C Pressure Switch
The fuC oressure switch is located in the condenser
outlet line where refrigerant is in a high
temperature/high pressure liquid state. The switch
will sense abnormally high or low pressure, and
open the circuit. This removes ground, and the
compressor will stop running.
Thermal Protectot
The thermal protector, located on the A,/C
compressor, opens and turns the compressor off if it
senses high temperature. Once the compressor
cools, the switch will close and the compressor will
begin running again.
Refer to the Service Manual (Section 22,
Air Conditioning) for specific tests or
troubleshooting procedures.
62-3

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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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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