2003 HONDA CIVIC Electrical

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

Fuel and Emissions Systems
General Troubleshooting Information (cont'd)
ECM Updating and Substitution for Testing
Special Tools Bequired
Honda Interface Module (HlM) EOS05435570
Use this procedure when you have to substitute a
known-good ECM in a troubleshooting procedure.
U pdate the ECM only if the ECN4 does not already have
the latest software loaded,
NOTE;. lMake sure the battery is fully charged before you
update the ECN4.. To prevent ECM damage during the update, do not
turn the ignition switch OFF, and do not use any of
the vehicle's electrical devices (light, horn, radio, etc. ).
How to Update the ECM
1. Turn the ignition switch ON (ll). Do not startthe
eng Ine.
2. Connect the Honda lnterface Module (HlM) to the
Data Link Connector {DLC) (A) located under the
driver's side of dashboard.
EOS05A35570
Do the ECM update procedure as described on the
HlN4 label and in the ECM update system.
11-6
\-
How to Substitute the ECM
'1. Remove the ECM f rom the vehicle.
2. Install a known-good ECM in the vehicle.
3. Rewrite the immobilizer code with the ECM
replacement procedure from the Honda PGM
Tester. lt allows you to start the engine.
4. After completing your tests, reinstall the original
ECM and rewrite the immobilizer code with the
ECM replacement procedure on the Honda PGM
Tester again.
L
(
I

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

ECM Data
You can retrieve data from the ECI\4 by connecting the OBD ll scan tool or the Honda PGM Tester to the data link
connector (DLC). The items listed in the table below conform to SAE recommended practice. The Honda PGM Tester
also reads data beyond that recommended by SAE to help you find the causes of intermittent problems.
The "operating values" listed are approximate and may vary depending on the environment and the individual
vehicle.
Unless noted otherwise, "at idle speed" means idling with the engine completely warmed up in the neutral position,
and the A,/C and all
Diagnostic
Trouble Code(DTC}
lf the ECM delects a problem, it will store it as a code
consisting of one letter and four numbers. Depending on
the problem, an SAE-defined code (Poxxx) or a Honda,
defined code {P1xxx) will be output to the tester.
The ECI\4 computes engine speed from the signals sent
from the crankshaft position (CKP) sensor. This data is
used for determining the time and amount of injected fuel.
detected, there is no
ourpul.
lf no problem is YES
Nearly the same as
tachometer indication
At idle speed;
The ECM converts pulse signals from the vehicle speed
sensor (VSS).Nearly the same as
speedometer
indication
Manifold
Absolute
Pressure(MAP)
The absolute pressure caused in the intake manifold by
engine load and speed.
With engine stopped: YES
Nearly the same as
almospnenc pressure.
At idle speed: about
20 4'1 kPa(150 310 mmHg,
6- 12 in.Hq).0.7 1.3 V
The ECT sensor converts coolant temperature into voltage
and signals the ECM. The sensor is a thermistor whose
internal resistance changes with coolant tempetature. The
ECM uses the voltage signals from the ECT sensor to
determine the amount of injected fuel.
With cold engine:
Same as ambient
temperature and IAT
With engine warmed
up; about 116 2'12"F
100'c).0.5-0.8 v
Air Fuel Ratio The A,/F sensor detects the oxygen content in the exha ust 0.0 - 1 .25 V(Ay'F) Sensor. gas and sends voltage signals to the Eclvl, Basedonthese 8.0 11.0mA(PGM(Sensor 1) signals, the ECM controls the airlfuel ratio. When the I Tester)
oxygen content is high (that is, when the ratio is leaner At idle speed:
than the stoichiometric ratio), the voltage signal is Iower. about 0.1 0.9 V
When the oxygen content is low (that is, when the ralio is
richer than the stoichiometric ratio). the voltage signal is
higher. The A'lF sensor signals are electrical current that
are indicated as voltaqe on the
The HO2S detects the oxygen content in the exhaust gas
and sends voltage signals to the ECM. Based on these
signals, the ECM controls the airlfuel ratio. When the
oxygen content is high (that is, when the ratio is leaner
than the stoichiometric ratio), the voltage signal is lower.
When the oxygen content is low (that is, when the ratio is
richer than the stoichiometric ratio), the voltage signal is
Secondary
Heated
Oxygen
Sensor(Secondary
H02S,
Sensor2)
0.0 1.25 V NO
At idle speed:
about 0.1 0.9 V
(cont'd)
11-13

Fuel and Emissions Systems
aSystem Descriptions (cont'dl
ECM Electrical Connections
\
No. INJECTOR
No,2INJECTOR
No.3 INJEC]OB
No./tINJECTOF
MAPSENSON
TPSENSOR
IATSENSOR
ECTSENSOB
\'
CMP SENSOR B(TDC SENSOSJ
CKPSENSOR
11-16
F€VERSE LOCKSOLENOIDVAIVE
\-

Fuel and Emissions Systems
System Descriptions (cont'd)
ECM Electrical Connections
\
ARAKE PEDALPOStTtON SWTTCH
IMMOBILPEN UN|T
EPS CONTROT UNIT
\
GAUGE ASSEMBLY
11-18
TERMINAL LOCATIONS
\-

Wire side o{ female terminals
NOTE: Standard baftery voltage is 12 V.
Terminalnumo€tWire color[erminal nameDescriptionSignal
BLUAvHTVTC+ lVTC OIL CONTBOLSOLENOID VALVE +SIDE)Drives VTC oilcontrolWith ignition switch ON (ll): 0 V
2lNJa {No. 4INJECTOR)Driveso. 4 iniectorAt idle: duty controlled
3BLJo.3INJECTORIDriveso.3 iniector4R1)TOR)Driveso.2 iniector
5BRNlNJl 1No. I INJECTOR)Drives No. 1 iniector
6GRNFANC (RAOIATOR FANCONTROL)Drives radiator fan relayWith radiator fan running: about 0 VWith radiator fan stopped: batterv voltaoe
7GRN/vVHTRVS (REVERSE LOCKSOLENOID VALVE)Drives reverse lock solenoidWith vehicle speed below 9.4 mph (15 km/h):battery voltageWith vehicle speed above 12.5 mph (20 km/h): 0 V
8REDAVHTECT (ENGINE COOLANTTFMPFRATURE SENSOR)Detects ECT sensor signalWith the ignition switch ON (ll): about 0.1 4.8 Videoendino on enoine coolant temDerature)
9BLU/BLKVTPSW (VTEC OILPRFSSTIRF SWITCH)Detects VTEc oil pressureswitch sionalWith engine at low engine speed: about 0 .Wirh enoine at hioh enoine soeed: batterv voltaqe
10WHT/BLUALTL (ALTEBNATOR LSIGNAI IDetects alternator L signalWith ignition swit'ch ON (ll): about 0 VWhh enoine runnino: batterv voltaqe
WHT/REDALTF (ALTERNATOR FRSIG NALIDetecls alternator FB signalWith engine running: about 0 V- 5 V{deoendinq on electrical load)
GRN/YELVTS {VTEC SOLENOIDDrives VIEC solenoid valveAt idle: about 0 V
'17REDI/ELIAT (INTAKE AIRTEMPERATURE SENSOR)Detects IAT sensor signalWith ignition switch ON {ll): about 0.1 V 4.8 vl.lcnen.iino on intake air temoerature)
18WHT/GRNALTC (ALTERNATOR
CONTROL)Sends alternator controlWith engine running: about 0 V 5 V(.lcocn.lino on electrical ioad)
21YEUBLUPCS {EVAPORATIVEEMISSION CANISTERPURGE VALVE)
Drives EVAPcanister purgevalveWith engine running, engine coolant below 149'F
165'C): battery voltageWith engine running, engine coolant above 149'F165"C): dutv controlled
23BLK/Vr'HTVTC (VTC OIL CONTROLSOI FNOID VALVE SIDE)Drives VTC oilcontrolWith the ignition switch ON (ll): 0 V
(confd)
11-21