Circuit HONDA CIVIC 2003 7.G User Guide

Circuit Diagram
' No.aloAl USAnod.lNo.20 itoAl C.md! modrlUISEF NOOD fUS'/iILAY IOX
-to ots BU/YIL
lcl H0Tii0llilllmdSTARTlllll
1 Honilsffroi
CTuICII PEDALP0sm0 swtrct
26 1113cnu6E coNTnoL uNtT l0
4-37

Cruise Control
Symptom Troubleshooting Index
NOTE:' The numbers in the table showthetroubleshooting sequence.. Before troubleshooting.- check the No, 10 (7.5A) and No. 4 (10A) fuses in the under-dash fuse/relay box. and the No. 7 (15A) fuse in theunder-hood fuse/relay box,- check that the horn sounds.- check the tachometer to see if it works properly.- check the speedometer lo see if it works properly.
SymptomDiagnostic procedureAlso check forCruise control cannot be
set
1. Check main switch (see page 4-42)
2. Check SET/RESUME/CANCEL switch (see page 4-42)
3. Test brake pedal position switch (see page 22-84) and checkits adjustment {see page 19,6)
4. Test clutch pedal position switch (see page 4-45) and check
its adjustment (see page 12-41
5. Check cruise control unit {see page 4-40}
6. Check vehicle speed sensor (VSS) (see page 22-65)
. Poor ground:
G501. Open circuit,
loose or
disconnected
term inals:
LT GRN,
BLI(ORN.
GRY/RED, BLU.
LT BLU,
BLUAA/HTCruise control can be set
but indicator light does
not go on
1. Check cruise control indicator bulb in gauge assembly {seepage 22-631
2. Check cruise control unit (see page 4-40)
. Poor ground:
G501. Open circuit,
loose or
disconnected
termrnats:
YEL, BLUA/ELar, 'i.a c^aa.l ic
noticeably higher or
lower than what was set
1. Check vehicle speed sensor (VSS) {see page 22-65)
Check cruise control actuator {see page 4-43)
2. Check cruise control unit (see page 4-40)
Excessive overshooting
or undershooting when
trying to set speed
1. Check cruise control actuator (see page 4-43)
2. Check vehicle speed sensor (VSS) (see page 22-65)
Check cruise control unit (see page 4-40)
3.
Speed fluctuation on a
flat road with cruise
control set
1. Check vehicle speed sensor (VSS) (see page 22-65)
Check cruise control actuator (see page 4-43)
2. Check cruise control unit (see page 4-40)
Vehicle does not
decelerate or accelerate
accordingly when SET/
RESUME/CANCEL button
is pushed
1. Check SET/RESU ME/CANCEL switch (see page 4-42)2. Check cruise control unit {see page 4-40)
Open circuit, loose
or disconnected
terminals:
GRY/RED,
LT GRN/BLKSet speed does not
cancel (engine rpm stays
high) when clutch pedal
is pushed
1. Testclutch pedal position switch (see page 4-45) and checkits adjustment (see page 12-4)
2. Check cruise control unit (see page 4-40)
Short to ground in
the LT BLU wire
Set speed does not
cancel when brake pedal
is pushed
'1. Test brake pedal position switch (see page 22-84) and checkits adjustment (see page 19-6)
2. Check cruise control unit (see page 4-40)
Open circuit, loose
or disconnected
terminals:
WHT/BLK
4-38
g,

svmptomDiagnostic procedureAlso check for
Set speed does not
cancel when main switch
is oushed OFF
1. Check main switch (see page 4-42)
2. Check cruise control unit (see page 4-40)
Short to power in
the LT GRN wire.
Set speed does not
cancel when CANCEL
button is pushed
1. Check SET/RESU ME/CANCEL switch (see page 4-42)
2. Check cruise control unit (see page 4-40)
Open circuit, loose
or disconnected
terminals:
GRYiRED,
LT GRN/BLK
Set speed will not
resume when RESUME
button is pushed (with
main switch on, and set
speed temporarily
cancelled by pressing the
brake Dedal)
1. Check SET/RESU ME/CANCEL switch (see page 4-42)
2. Check cruise control unit {see page 4-40)
Open circuit, loose
or disconnected
terminals:
LT GRN/BLK
4-39

Engine Cooling
Cooling System
Component Location Index ......................................... 10-2
Radiator Cap Test ..................... .......... 10-3
RadiatorTest ............. 10-3
Fan Motor Test .......... l0-4
Thermostat Test ...................... ........... 10-4
Water Pump Inspection ..................... 10-5
Water Pump Replacement ................. 10-5
Coolant Check .............. ....................... 10-6
Coolant Replacement ......................... 10-6
Thermostat Replacement .................. 10-8
Water Passage Installation ................ 10-9
Water Outlet Installation .................... 10-9
Radiator and Fan Replacement ................................... 10-10
Fan Controls
Component Location Index ......................................... 10-11
Symptom Troubleshooting Index ............................... 10-12
Circuit Diagram ......... 10-13
Radiator Fan CircuitTroubleshooting ........................ 10-14
Radiator Fan Switch Circuit Troubleshooting
(Open) ............ ........ 10-16
Radiator Fan Switch Circuit Troubleshooting
(Short) ............ ........ 10-16
Radiator Fan Switch Test ................... 10-17
Radiator Fan Switch Reolacement .............................. 10-17

Fan Controls
Symptom Troubleshooting Index
Before performing any troubleshooting procedures check:. Fuses. Grounds. Cleanliness and tightness of all connectors
\{
\,4
SYMPTOMPROCEDURE
Radiator fan does not run at allRadiator Fan Circuil Troubleshooting (see page 1O-14).
Radiator fan does not run for engine cooling, but it runswith A,/C ON
Radiator Fan Switch Circuit Troubleshooting (Open)
(see page 10-16).
Radiator fan runs with ignition switch ON (ll), Ay'C OFF,
and engine temperature below 199"F (93"C)Radiator Fan Switch Circuit Troubleshooting (Short)
(see page 10-'16).
10-12
\-

oCircuit Diagram
UIIDEF HOOD FJSE/NILAY BOX
' No.20loA) : USA moddNo.20l50A) : Cm.de mod.l
UNDEN DASXFUSE/RELAY BOX
lG2H0TiiAClill,0N{lllrndSTABI llll)
10-13

Fan Gontrols
Radiator Fan Circuit Troubleshooting
1. Check the No. 4 (20A) fuse in the under-hood
fuse/relay box, and the No. 14 (10A) fuse in the
under-dash fuse/relay box.
ls the tuse (s) OK?
YES-Go to step 2.
NO- Replace the fuse (s) and recheck.l
2. Remove the radiator fan relay from the under-hood
fuse/relay box, and test it (see page 22-51).
ls the relay OK?
YES Go to step 3.
NO Replace the radiator fan relay. t
3. Measure the voltage between the No. 2 terminal of
the radiator fan relay 4P socket and body ground.
RADIATOR FAN RELAY 4P SOCKET
Terminal side of female terminals
ls there battery voltage?
YES Go to step 4.
NO Replace the under-hood fuse/relay box. I
10-14
\-
(
4. Connect the No. landNo.2terminalsofthe
radiator fan relay 4P socket with a jumper wire.
RADIATOR FAN RELAY 4P SOCKET
JUMPERWIRE
Terminal side of Iemale terminals
Does the radiatot fan run?
YES Go to step 5.
NO Go to step 6.
Disconnect the jumper, and turn the ignition switch
ON { ll}. Check for voltage between the No. 3
terminal of the radiator fan relay 4P socket and
body ground.
BADIATOB FAN RELAY 4P SOCKET
Termlnal side of female terminals
ls there battety voltage?
YES-Go to step 9.
NO Check for an open in the wire between the
under-hood fuse/relay box and under-dash fuse/
relay box.l
\-

Fan Controls
Radiator Fan Switch Circuit
Troubleshooting (Openl
1. Disconnect the radiator fan switch 2P connector.
2. Turn the ignition switch ON (ll).
3. Measure voltage between the No.2 terminal ofthe
radiator fan switch 2P connector and body ground.
RADIATOR FAN SWITCH 2PCONNECTOR
ls there battety voltage?
YES-Go to step 4.
NO- Repair open in the wire between the radiator
fan switch 2P connector terminal No. 2 and under-
hood fuse/relay box.l
Turn the ignition switch OFF, and check for
continuity between the No. '1 terminal of the
radiator fan switch 2P connector and body ground.
RADIATOB FAN SWITCX 2PCONNECTOR
ls there continuity?
YES Replace the radiator fan switch. t
NO Check for an open in the wire between theradiator fan switch 2P connector terminal No. 1 and
body ground. lf the wire is OK, check for a poor
ground at G301.1
10-16
\-
Radiator Fan Switch Circuit
Troubleshooting (Short)
NOTE: After troubleshooting, perform the engine
control module (ECM)idle learn procedure (see page
1 1,139).
1. Remove the radiator fan relay from the under-hood
fuse/relay box, and test it (see page 22-51).
ls the relay OK?
YES Go to step 2.
NO Replace the radiator fan relay.I
2. Remove the radiator fan switch, and test it (see
page 10-17 ).
Is the radiatot tan switch OK?
4.
YES Go to step 3.
NO Replace the radiator fan switch.I
Disconnect the battery negative cable from the
battery.
Disconnect engine control module {ECM) connector
B (24P) and the under hood fuse relay box 14P
connector.
Check for continuity between the No. 2 terminal of
the radiator fan switch 2P connector and bodygrouno.
RADIATOR FAN SWITCH2P CONNECTOR
lstnere continuity?
YES Repair short in the wire between the radiator
fan switch 2P connector terminal No. 2 and under-
hood fuse/relay box.l
NO Replace the under-hood fuse/relay box.t
\I
\

Fuel and Emissions
Fuel and Emissions Systems
SpecialTools
General Troubleshooting
Information
DTC Troubleshooting lndex ....
Symptom Troubleshooting
1ndex...............
System Descriptions ................
Howto Set Readiness Codes ..
PGM-FlSystem
Component Location Index ....
DTC Troubleshooting ..............
MIL Circuit Troubleshooting ...
DLC Circuit Troubleshooting ..
Injector Replacement ...............
A,/F Sensor Replacement .........
Secondary HO2S
Replacement
ECT Sensor Reolacement .......
CMP Sensor B {TDC Sensor)
Replacement
IAT Sensor Replacement .........
Knock Sensor Replacement ....
CKP Sensor Reolacement .......
VTEC/VTC
Comoonent Location Index ....
DTC Troubleshooting ..............
VTC Oil Control Solenoid
Valve Removal/Test .............
CMP Sensor A Replacement ...
VTEC Solenoid Valve
Removal/lnsoection .............
ldle Control System
Component Location Index
DTC Troubleshooting ..............
A,/C Signal Circuit
TroubleshootinS ...................
Alternator FR Signal Circu it
TroubleshootinS ...................
EPS Signal Circuit
TroubleshootinS ...................
Brake Pedal Position Switch Signal
Circuit Troubleshooting .............
ldle Speed Inspection
ECM ldle learn Procedure .......
Fuel Supply System
Component Location Index
Fuel Pump Circuit Troubleshooting
1't-2
I I-J
11-7
1 1-10
11-12
11-46
11-49
11-52
11-97
11-109
11-111
11-113
11-113
11-114
11-114
11-115
11-115
11-116
11-117
1 1-1 18
11-127
11-128
11-128
11-129
1I-130
I t- t55
11-134
1 1- 135
1 1-137
1 1-138
1 1-139
1 1-140
11-141
11-144
Fuel PressureTest ................... 11-145
Fuel Lines Inspection ............... 11-146
Fuel Line/Ouick-Connect
Fittings Precautions ............. 1 1-148
Fuel Line/Ou ick-Con nect
Fittings Removal .................. 1 1-149
Fuel Line/Ou ick-Con nect
Fittings lnstallation ............... 11-150
Fuel Pressure Regu lator
Replacement ......................... 11-152
Fuel Fifter Replacement ........... 11-152
Fuel Pump/Fuel Gauge Sending
UnitReDlacement ................. 11-153
Fuel Pulsation Damoer
Rep1acement ......................... 11-154
Fuel Tank Reolacement ........... 11-155
Fuel GaugeSending UnitTest ....... 11-156
Low Fuel lndicatorTest ................. 1 1-158
Intake Air System
Comoonent Location Index .... 11-159
Throttle BodyTest ................... 11-160
Intake Air Bypass Control
Thermal Valve Test .............. 11-161
Air Cleaner Reolacement ........ 11-162
Air Cleaner Element
Reolacement ......................... 11-162
Throttle Cable Adjustment ...... 11-163
Th rottle Cable
Removal/lnstallation ............ 1 1-164
Th rottle Body Removal/
Installation .. 11-165
Th rottle Body Disassembly/
Reassemblv .......................... 11-166
Catalytic Converter System
DTC Troubleshooting .............. 1 1-167
PCV System
DTC Troubleshooting .............. 1 1-168
PCV Valve InsDection
and Test ...... 1 1- 169
PCV Valve Reolacement .......... 11-169
EVAP System
Component Location Index .... 11-170
DTCTroubleshooting .............. 11-171
EVAP Two Way Valve Test ...... 11-186
Fuel Tank Vaoor Control
Valve Test ... 11-187
EVAP Canister Replacement ... 11-189
Fuel Tank Vaoor Control
Valve Reolacement .............. 1 1-189Fuel Pressu re Relieving ...........

General Troubleshooting Information
Intermittent Failures
The term "intermittent failure" means a svstem mav
have had a failure. but it checks OK now. lf the
Malfunction Indicator Lamp (MlL) on the dash does not
come on, check for Door connections or loose terminals
at all connectors related to the circuit that Vou are
troubleshooting.
Opens and Shorts
"Ooen" and "Short" are common electrical terms. An
open is a break in a wire or at a connection. A short is
an accidental connection of a wire to ground or to
another wire. In simple electronics, this usually means
something won't work at all. With complex electronics(such as ECMs)this can sometimes mean something
works, but not the way it's supposed to.
How to Use the PGM Tester or a Scan Tool
lf the MIL {Malfunction Indicator Lamp} has come on
'1. Start the engine and check the MIL {A).
NOTE: lf the ignition switch is turned ON (ll), and
the engine is not started, the MIL will stay on for
15 20 seconds (see page 11-46).
K-> ;"PN/.- -::: - -d V-: !
w:ix&K#
2. lf the MIL stays on, connect the Honda PGM Tester(A) or an OBD ll scan tool to the Data Link
Connector {DLC) (B) located under the driver's side
of the dashboard.
3.
5.
Turn the ignition switch ON (ll).
Check the Diagnostic Trouble Code (DTC) and note
it. Also check the freeze data. Refer to the DTC
Troubleshooting Index, and begin the appropriate
troubleshooting procedure.
lf you do not find any DTCS, go to MIL circuit
troubleshooting (see page 11-97).
NOTE:. Freeze data indicates the engine conditions when the
first malfunction, misfire, or fuel trim malfunction
was detected.. The scan tool and the Honda PGM Tester can read the
DTC, freeze data, current data, and other Engine
Control l\4odule {EClvl) data.. For specific operations, refer to the user's manual
that came with the scan tool or Honda PG l\4 Tester.
lf the MIL did not stay
lf the MIL did not come on but there is a driveability
problem, refer to the Symptom Troubleshooting Index
in this section.
lf you can't duplicate the DTC
Some of the troubleshooting in this section requires
you to reset the ECM and try to duplicate the DTC. lf rhe
problem is intermittent and you can't duplicate the code,
do not continue through the procedure. To do so will
only result in confusion and, possibly, a needlessly
replaced ECM.
(cont'd)
11-3