2003 HONDA CIVIC Circuit

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

How to Troubleshoot Circuits at the ECM
Special Tools Required. Digital Multimeter KS-AHM-32-003 (1) or a
commercially available digital multimeter. Backprobe Set 07SAZ-0010004 (2)
1. Connect the backprobe adapters (A) to the stacking
patch cords (B), and connect the cords to a digital
multimeter (C).
07sAz-001000A
2. Using the wire insulation as a guide for the
contoured tip ofthe backprobe adapter, gently slide
the tip into the connector from the wire side until it
touches the end of the wire terminal.
3. lf you cannot get to the wire side of the connector
or the wire side is sealed (A), disconnect the
connector and probe the terminals (B) from the
terminal side. Do not force the Drobe into the
connector.
Do not puncture the insulation on a wire.
Punctures can cause Door or intermittent
electrical connections.
(cont'd)
11-5

DTC Troubleshooting Index
";These DTCs are indicated by a blinking malfunction indicator lamp (MlL)when the SCS service signal line isjumped with the Honda PGM Tester.
{cont'd)
11-7
DTC
{MlL indication*)
Temporary DTCDetection ltemNote
P0010 (56)Variable Valve Timing Control {VTC) Oil Control
Solenoid Valve Malfunction
{see page 1 1'1 18)
P0011 (56)P001 1Variable Valve Timing Control (WC) System
Malfunction
(see page 11- 1 19)
P0107 (3)Manifold Absolute Pressure (MAP) Sensor Circuit
Low Voltaqe
(see page 1'l-521
P0108 (3)Manifold Absolute Pressure (MAP) Sensor Circuit
Hiqh Voltaqe
(see page 11-53)
P0112 (10)Intake Air Temperature (lAT) Sensor Circuit Low
Voltaoe
(see page 11-55)
P01r3 (10)Intake Air Temperature (lAT) Sensor Circuit High
Voltaoe
(see page '11-56)
P0116 {86) P0116Englne Coolant Temperature (ECT) Sensor Range/
Performance Problem
{see page 11-57)
P0117 {6)Engine Coolant Temperature (ECT) Sensor Circuit
Low Voltaqe
(see page 11-58)
P0118 {6)Engine Coolant Temperature (ECT) Sensor Circuit
Hiqh Voltaqe
{see page 11-59)
P0122 t7\Throttle Position (TP) Sensor Circuit Low Voltaqe(see Daqe 11-60)P0123 {7)Throttle Posltion (TP) Sensor Circuit Hiqh Voltaoe(see paqe 11-62)
P0128 (87)P0128Coolinq SVStem Malfunction(see Daqe 11-64)
P0134 (41)Air Fuel Ratio (Ay'F) Sensor (Sensor 1) No Activity
Detected
(see page 11-65)
P0137 (63)P0137Secondary Heated Oxygen Sensor (Secondary HO2S)(Sensor 2) Circuit Low Voltaqe
(see page 11-65)
P0138 (63)P0138Secondary Heated Oxygen Sensor (Secondary HO2S)(Sensor 2) Circuit Hiqh Voltaqe
(see page 11-66)
P0139 (63)P0139Secondary Heated Oxygen Sensor (Secondary H02S)(Sensor 2) Slow ResDonse
(see page 11-67)
P0141 (65)Secondary Heated Oxygen Sensor (Secondary H02S)(Sensor 2) Heater Circuit Malfunction
(see page 11-68)
P0171 (45)PO\11Fuel Svstem Too Lean(see paqe 11-70)
PO112 l'45)PO\l2Fuel System Too Rich(see oaoe 11-70)
P0300 and any P0300 and any
of of
P0301 (71) P0301
PO302 (721 P0302
P0303 (73) P0303
P0304 (74) P0304
Random Misfire(see page 11-71)
P0301 (7'1) P0301No. 1 Cylnder Misfire{see page 11-72)
P0302 (721 P0302No. 2 Cvlnder Misfire{see paqe 1 1-72)
P0303 (73)P0303No. 3 Cvlnder Misfire(see oaqe 11-72)
P0304 {74)P0304No. 4 Cvlnder Misfire{see Daqe 1 1-72)

Fuel and Emissions Systems
Knock Sensor Circuit N4alfunction
Crankshaft Position (CKP) Sensor Intermittent(see page 11-78)
(see oaqe 11-121
PO4i{
TU45I
P0452
Camshaft Position (CMP) Sensor A Intermiftentisee page 11-121)
Yetrgb-le Velye TiTing _controlll/T!) Phqse Gsee oaoe 11-122
CqJalyst System Elficie-ncy Below Thresholdsee oaqe 1 1- 167
Fuel Tank Pressure (FTP) Sensor Range/Performance (seepagell 171)
Sensor Circuit Low V11-172
Fuel Tank Pressure (FTP) Sensor Circuit High V
Vehicle SDeed SensorCircuit Malf unction
Camshaft Position (CMP) Sensor A No
P0451 (91)
see Daqe 11-130)
(see page 1 1-81)
Refer to the l\4ultiplex
Control System
Troubleshooting {see
(see page 1 1-83)
(see paSe 1 1'83)
Barometric Pressure (BARO) Sensor Circuit High{see page 11-83)
P't 121
Pl122
P11f,.8
Throttle Position {TPi Sensor Signal Lower Than(see page 11-63)
-tsee page I r-oJ,
G;tp"s" 1 154)
(*" paSe 1 154)
P1122 ll J
ij1128 (5)
Throttle Position (TP) Sensor Signal Higher Than
Mani{old Absolute Pressure (l\,4AP} Sensor Signal
Loqer Tha n Expected
Manifold Absolute Preisure (MAP) SeiiioiSgnul
Hiqher Than Ex(see page 11-84)
Engine Control Module (ECN4) Power Source Circuil
Serial Communication Link Malfunction
P1106 (13)
P110? (13
P1 108 (ts'
Barometric Pressure (BARO) Sensor Range/
Performance Problem
Barometric Pressure (BARO) Sensor Circuit Low
P1121 11)
P1 129 (5)
P1157 (48)
Pr 158 (48)
Air Fuel Ratio (AVF) Sensor (Sensor 1) Range/
Rerformance Problem
AirFuel Ratio{A"F) Sensor {Sensor 1)AFS Terminal(see page 1 1-85)
Air Fuel Ratio 1AVF) Sensor isensor 'l) AFS + Terminal(see page 1 1-86)
Air Fuel Ratio {A,/F) Sensor {Sensor I ) Slow Response
Air Fuel Ratio (A/F) Sensor (Sensor 1) Range/(see page 1 1-88)
Air Fuel Ratio (4,/F) Sensor (Sensor 1) Heater Circuit
Malfunction
(see page 11-89)
Air Fuel Ratio (A,/F) Sensor (Sensor 1) Heater System
Malfunction
(see page 11-91)
P1 159 (48)
P1163 (61
P1164 (61)
P1 166 (41)
P1 167 (41) '
DTC Troubleshooting Index (cont'd)
" :These DTCS are indicated by a blinking MIL when the SCS servlce signal line is jumped with the Honda PGM
Tester.* 1r '02 model
\
l\."
11-8
\.
(
a

DTC
{MlL indication*l
Temporary DTCDetection ltemPage
P1259 t22JVTEC System l\4alfunction(see Daqe 11-123)P1291 t20\Electrical Load Detector (ELD) Circuit Low Voltaqe(see Daqe l1-92)P1298 (20)Electrical Load Detector (ELD) Circuit Hiqh Voltaqe(see oaoe 11-93)P1361 (8)Camshaft Position (CMP) Sensor B (Top Dead Center(TDC) Sensor) Intermittent Sional InterruDtion
(see page 11-95)
P1362 (8)Camshaft Position (CMP) Sensor B (Top Dead Center(TDC) Sensor) No Siqnal
(see page 11-95)
P'r456 (90)P1456Evaporative Emissions (EVAP) Control System
Leakaqe (Fuel Tank Svstem)
(see page 11-175)
P14s7 (90)P1457Evaporative Emissions (EVAP) Control System
Leakaqe (EVAP Canister Svstem)
(see page 1'l-180)
P1505 (109)P1505Positive Crankcase Ventilation (PCV) Air Leakaqe(see oaqe 11-1681
P1519 (14)ldle Air Control (lAC) Valve Circuit Malfunction{see paqe 11-131)P1607 ( )Engine Control Module (ECM) Internal Circuit
Malfunction
(see page 1 1-96)
" : These DTCS are indicated by a blinking MIL when the SCS service signal line is jumped with the Honda PGM
Tester.
11-9