unit test HONDA CIVIC 1996 6.G Repair Manual

rl
Troubleshooting
t)
Self-diagnostic Procedures
The self-diagnostic function of the SRS system allows it to locate the causes of system problems and to store this informa' I
tion in memory. For easier troubleshooting, this data can be retrieved via a data link circuit l
. When you turn the ignition switch ON (ll), the SRS indicator will come on. ll it goes off after six seconds. the system is
norma l.
. lf there is an abnormality, the system locates and defines the problem, stores this information in memory, and turns
the sRS indicator light on. The data will remain in the memory even when the ignition switch is turned off or if the bat-
tery is disconnected.
o when you connect the scs service connector to the service check connector (2P), and turn the ignition switch oN (ll),
thesRsindicator|ightwi||indicatethediagnostictroub|ecode(DTC)bythenumberofb|inks.
. After reading and recording the DTC. proceed with the troubleshooting for this code'
Precauiions
.Useon|yadigita|mU|timetertocheckthesystem'|fit,snotaHondamu|timeter,makesureitsoutputisl0mA(0.01A)
or|esswhenSwitchedtothesma||estva|ueintheohmmeterrange,AtesterwithahigheroUtpUtcoulddamagethe
airbag circuit or cause accidental airbag deployment and possible injury'
r when-ever the ignition switch is oN (ll). or has been turned oFF for lessthan three minutes, be careful nottobumpthe
SRS unit; the airbags could accidentally deploy and cause damage or injuries
. Before you ,"n1ou" th" SRS main harness, disconnect the driver's airbag connector (and the front passenger's airbag
connector).
. Make sure the battery is sufficiently charged {see section 23}. lf the battery is dead or low, measuring valLles won t be
correct.
. Do not touch a tester probe to the terminals in the sRS unit or harness connectors, and do not connect the terminals
with a jumper wire. Use only the backprobe set or the special tools'
For backprobing spring-loaded lock type connectors, refer to page 24-9'
Reading the DTC
when the SRS indicator light is on, read the DTC using one of these methods:
A. Connect the Honda PGM Tester to the 16P Data Link Connector {DLC), and follow the tester's prompts lf the tester
indicatesnoDTc,DTcg-1orDTc9-2,doub|e-checkbyjumpingtheservicecheckconnectorandwatchingthesRS
indicator light (see next Page)
HONDA PGM TESTER
DATA LINK CONNECTOR Il6PI
l,
24-13

)Erasing the DTC Memory
To erase the DTC(s) from the SRS unit, use a Honda
PGM Tester (see the Honda PGM Tester SRS vehicle
System Supplement) or the following procedure
1. Make sure the ignition switch is OFF
2. Connect the SCS service connector to the MES con-
nector (2P). Do not use a jumper wlre.
]P,
&
.!--J
MEMORY ERASE
SIGNAL (MESI CONNECTOR I2PI
IGRY, GRYI or [GRN, GRNI
SCS SERVICE CONNECTORo?PAZ - 0010100
t
7.
Turn the ignition switch ON (ll).
The SRS indicator light comes on for about six sec-
onds and goes off. Remove the SCS service connec-
tor from the MES connector (2P) within four seconds
after the SRS indicator light went off.
The SRS indicator light comes on again. Reconnect
the SCS service connector to the lvlES connector
(2P) within the four seconds after the SRS indicator
light comes on.
The SRS indicator light goes off. Remove the SCS
service connector from the MES connector (2P)
within four seconds.
The SRS indicator light indicates that the memory is
erased by blinking two times.
Turn the ignition switch OFF, and wait for ten sec-
onos.
8.
SRS indictlorlighi
MESconncclottcaminals
CONNECTED
O,
DISCONI{ECTED
24-15
Troubleshooting Intermittent
Failures
lf there was a malfunction, but it doesn't recur, it will be
stored in the memory as an intermittent failure, and the
SRS indicator light comes on.
Afte. checking the DTC, troubleshoot as lollows:
1. Read rhe DTC {see "Reading the DTC"}.
Erase the DTC memory (see "Erasing the DTC
Memory").
With the shifi lever in neutral, turn the ignition switch
ON (ll), and lei the engine idle.
The SRS indicator light comes on for about six sec-
onds and goes off.
l*F
ON
tl-- -l
Shake the wire harness and the connector, take a test
drive (quick acceleration, quick braking, cornering),
and turn the steering wheel fully left and right, and
hold it there for five lo ten seconds to find the cause
of the intermittent failure.
lf the problem recurs, the SRS indicator light will
stay on.
-q 6a.c f'-
:q
Problem recurs, light stays on
3.
4.
6.lf vou can't duplicate the intermittent failure, the sys-
tem is OK at this time.

Troubleshooting
Diagnostic Trouble Code (DTCI Ghart -'96 - 97 Models (cont'd)
NOTE:* l: In case of an intermittent failure DTC g-1, it means there was an internal failure of the SRS unit or a faultv SRS indicator light circuit. Do the troubleshooting for intermittent failures (see page 24-15).*2: lt both DTC 9-2 and DTC 5-1 are indicated, do the troubleshooting for DTC g-2.*3: Apply to the '97 model coupe HX and DX.*4: DTC cannot be read with a Honda PGM Tester; check by jumping the SCS service connector.
24-18
.
Possiblg cause Cortestive action
5 3 I Internal failure of the SRS unitSRS unit
replacement
lnternal failure of the SRS unitSRS unit
replacement
Internal failure of the SRS unit
Internal failure of the SRS unitSRS unit
replacement
Internalfailure of the SRS unit ortwo failures at atime
8-6*3 Internalfailure ofthe SRS unit
Internal failure of the SRS unit
Faulty SRS power supply (VB line)
SRS unit replacement code (SRS unit must not
be used any longe.)
J

Troubleshooting
Diagnostic Trouble Code (DTC) Chart -'98 - 00 Models {cont'dl
NOTE:* 1: In case of an intermittent failure DTC 9-1, it means there was an internal failure of the SRS unit or a faulty SRS indica-
tor light circuit. Do the troubleshooting for intermittent failures (page 24-'15).*2: In case of an intermittent failure DTC 9-2, it means there was an internal failure of the power supply {VB line). Do the
troubleshooting for intermiftent failures.*3: DTC cannot be read with a Honda PGM Tester; check by jumping the SCS service connector.
24-20
\
SRS indicator lightDTCPossible causeCorrectiYe actionSee page
comes on
5-1lnternal failure of the SRS unitSRS unit
replacemenl24-765-4
6-1
lnternal failure of the SRS unitSRS unit
replacement24-7 66-2
o-5
6-4
7-1
lnternal failure of the SRS unitSRS unit
replacement24-76
7-3
8-1lnternal failure of the SRS unitSRS unit
reptacement24-7 68-2
8-6Internal failure of the SRS unit or two failures
at a trmeTroubleshooting24-62
g_1*r *3lnternal failure of the SRS unitSRS unit
replacement24-7 6
9-2+2 *3lnternal failure of the SRS unit5l|5 Untr
replacement24-76
10-1SRS airbags deployed (SRS unit must be
reDlaced)
SRS unit
replacement24-76

Troubleshooting
Diagnostic Trouble Code (DTCI Ghart -'98 - 00 Models (cont'd)
NOTE:*l: In case of an intermittent failure DTC 9-1. it means there was an internal failure of the SRS unit or a faultv SRS indica-
tor light circuit. Do the troubleshooting for intermiftent failures (pa9e 24-15).*2: In case of an intermittent failure DTC 9-2, it means there was an internal failure of the power supply (VB line). Do thetroubleshooting for intermittent failures.*3: DTC cannot be read with a Honda PGM Tester; check by jumping the SCS service connector.
SRS indicator lightDTCPossible causeCorective actionSeo page
comes on
5-2
53
54
lnternal failure of the SRS unitSRS unit
replacement24-7 6
6-1
6-2
_
64
Internal failure of the SRS unitSRS unit
replacement24-16
n
-
8l
8S
9_1*r *3
Internal failure of the SRS unitSRS unit
reptacement24-76
Internal failure of the SRS unitSRS unit
replacement24-76
Internal failure of the SRS unitSRS unit
replacement24-76
Internal failure of the SBS unitSRS unit
reptacemenr24-76
10-1SRS airbags deployed (SRS unit must be
reDlaced)
SRS unit
replacement24-76
24-22

Troubleshooting
Diagnostic Trouble Code (DTG) Chart -'98 - 00 Models (cont'dl
NOTE:*'l: In case of an intermittent failure DTC 9-1. it means there was an internal failure of the SRS unit or a faulty SRS indica-
tor light circuit. Do the troubleshooting for intermiftent failu.es (page 24-15).*2: In case ot an intermittent failure DTC 9-2. it means there was an internal failure of the power supply (VB line). Do the
troubleshooting for intermift ent failures.*3: DTC cannot be read with a Honda PGM Tester; check by jumping the SCS service connector.
24-24
a,
SRS indicator lightDTCPossible causeCorective actionSee page
comes on
lnternal failure of the SRS unitSRS unit
repracemenl24-765-4
6-3lnternal failure of the SRS unitSRS unit
reptacemenr24-766-4
Internal failure of the SRS unitSRS unit
replacement24-7 6
8-1
lnternal failure ot the SRS unitSRS unit
replacement24-7 68-2
8-6
g_1*r *rInternal failure of the SRS unitSRS unit
replacement24-16
lnternal failure of the SRS unitSRS unit
repracemenl24-76
10-1SRS airbags deployed (SRS unit must be
.eplaced)
SRS unit
reptacemenl24-76

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

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

How the Gircuit Works
All Except GX
Do not smoke while working on the fuel system.
Keep open flame away trom the work area. Drain
fuel only into an approved container.
A thermistor is mounted in the fuel tank unit. When
the thermistor is cool, its resistance is very high.
When the thermistor's temperature increases, its
resistance decreases. Fuel in the fuel tank transters
heat away lrom the thermistor fast enough to keep it
cool so the thermistor's resistance stays high and
lhe low fuel indicator light does not come on. When
the fuel level drops below the thermistor, the
thermistor's temoerature increases. Without the fuel
to cool it, the thermistor's resislance decreases,
allowing current to llow through the low fuel
indicator light and the thermistor to ground, and the
low fuel indicator light comes on.
Refer to the Service Manual (Section 23, Electrical)
for specific tests or troubleshooting procedures.
GX
The PCM turns on the low fuel indicator light when
the fuel level is low. The PCM will also blink the
indicator light when a problem is detected by the
fuel tank pressure sensor or the fuel tank
temperature sensor.
Refer to the Service Manual GX Supplement
(Section 11 , Fuel and Emissions) for specific tests
or troubleshooting procedures.
74-1