Fuel trouble HONDA CIVIC 1997 6.G Owner's Guide

Troubleshootin g Procedures
Chccking the Diagnostic Trouble Code IDTC)with an OBD ll Scan tool or Honda PGM Tester
when the PCM senses an abnormality in the input or output systems, the pl indicator light in the gauge assembly willblink. When the 16P Data Link Connector (DLC) (located under the dash on the driver,s side) is connected to the OBD llScan Tool or Honda PGM Tester as shown, the scan tool or tester will indicate the Diagnostic Trouble Code (DTC) whenthe ignition switch is turned ON{ll).
lf the El indicator light or the MIL has been reported on, or lf a driveability problem is suspected, follow this procedure:
1. Connect the OBD ll Scan Tool (conforming to SAE J19781 or Honda PGM Tester to rhe 16p DLC. (See the OBD ll ScanTool or Honda PGM Tester user's manual for specific instructions. lf you are using the Honda PGM Tester, make sure itis set to the SAE DTC type.)
2. Turn the ignition switch ON (lll, and observe the DTC on the screen,3, Record all fuel and emission DTCS, A/T DTCS, and freeze data.4 lf there is a fuel and emissions DTC, first checkthe fuel and emissions system as indicated bythe DTC (except for DTCP0700). DTC P0700 means there is one or more A,/T DTC, and no problems were detected in the fuel and emissions cir-cuit of the PCM.
5. Write down the radio station oresets.
6. Reset the memory with the PGM Tester or by removing the BACK UP fuse in the passenger's under-dash fuse/relay boxfor more than 10 seconds.
7. Drive the vehicle for several minutes at speeds over 30 mph (50 km/hr), and then recheck for DTCS. lf the A"/T DTCreturns, go to the Symptom-to Component Chart on pages 14-52 and 14-53 for'96 - 98 models, and pages 14-54 and14-55 for the'99 - 00 models, lf the DTC does not return, there was an intermittent problem within the circuit. Makesure all pins and terminals in the circuit are tight, and then go to step g.
8. Reset the radio preset stations, and set the clock.
OBD ll SCAN TOOL orHONDA PGM TESTER
DAYA LINK CONNECTOR {16P}
14-44

l'f .
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.

How To Use This Manual
The next few pages describe how this manual is organized. They also
explain what kind of information the manual contains, what that
informalion means, and how to use it to troubleshoot electrical problems.
Circuit schematics break the entire electrical system into individual
systems, like the Low Fuel lndicator Light on the nelit page.
Only electrical components that work together are shown together,
so you won't be distracted by unrelated wires.
Explanations of the abbreviations and svmbols used in the schematics
begin on page [Fl. You'll need to know what they mean before you can use
a schematic effectively.

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

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
(
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.
a
a