2003 HONDA CIVIC Head

DTC Pl298: ELD Circuit High Voltage
1. Resetthe ECM (see page 11-4)
2. Stan the engine.
3. Turn on the headlights.
ls DTC P1298 indicated?
YES-Go to step 4.
NO- Intermittent failure. system is OK at this time.
Check for poor connections or loose terminals at
the ELD and at the ECM.I
4. Turn the ignition switch and headlights OFF.
5. Disconnectthe ELD 3P connector.
6. Turn the ignition switch ON (ll).
7. Measure voltage between body ground and ELD 3P
connector terminal No. 1.
ELD 3P CONNECTOR
IG1 IBLK/ORNI
Wire side ot {emale terminals
ls there battery voltage?
YES-Go to step 8.
NO-Checkthe No. 4 ACG (10A)fuse in the under-
dash fuse/relay box. lf the fuse is OK, repair open in
the wire between the No. 4 ACG (10A) fuse and the
ELD.I
8.
9.
10.
11.
Turn the ignition switch OFF.
Connect ELD 3P connector terminal No. 3 to body
ground with a jumper wire.
Disconnect ECM connector E (31P).
Check for continuity between body ground and
ECM connector terminal E15.
ECM CONNECTOR E 131PI
1 21345ot/II
14LC6l/ 182C21
22123 2421 ./2Q30J
ELDIGRN/RED)i1'
Wire side of female terminals
Is thete continuity?
YES-Go to step 12.
NO Repair open in the wire between the ECM
(E15) and the ELD.
(cont'd)
ELD 3P CONNECTOR
---F-------
l1l2 :rlELD(GRN/RED)
IJUMPER wrRE
II
Wire side of temale terminals
11-93

PGM-FI System
DTC Troubleshooting (cont'dl
12, Check for continuity between ELD 3P connector
terminal No.2 and body ground.
ELD3P CONNECTOR
Wire side of female terminals
ls there continuity?
YES Go to step 13.
NO- Repair open in the wire between the ELD and
G201. I
Reconnect the ELD 3P connector and ECM
connector E (31P).
Start the engine and let it idle.
While measuring voltage between ECM connector
terminals 424 and E15, turn the headlights on
th igh).
ECM CONNECTORS
Wi.e side of female terminals
Does the voltage drop?
YES-Update the ECM if it does not have the latest
software, or substitute a known-good ECM, then
recheck {see page 1 1-6). lf the symptom/indicationgoes away with a known-good ECM, replace the
original ECM.I
NO Replace the ELD.I
14.
t5_
11-94

VTEC/VTC
10.
DTC Troubleshooting (cont'd)
Measure voltage between ECM connector terminal
A25 and body ground.
ECM CONNECTOR A 131P)
Wire side of female te.minals
ls there about 5 V?
YES-Repair open in the wire between the ECM(A25) and CMP sensor A.I
NO-Go to step 11.
Turn the ignition switch OFF.
Disconnect ECM connector A (31P)
Check for continuity between ECM connecror
terminal A25 and body ground.
ECM CONNECTON A 131P}
Wire side of femaleterminals
ls tnere continuity?
YES-Repair short in the wire between the ECM(A25) and the CMP sensor A. t
NO Update the ECt\4 if it does not have the latest
software, or substitute a known-good ECM, thenrecheck (see page 1 1-6). lf the symptom/indicationgoes away with a known-good ECM, replace the
original ECM.I
11.
't2.
11-122
DTC P0341: WC Phase Gap
1. Resetthe ECM {see page 11-4).
2. Start the engine.
ls DTC P0341 indicated?
YES Go to step 3.
NO Intermittent failure, system is OK at this time.Check for poor connections or loose terminals atthe CMP sensor A and at the ECM.I
3. Check the VTC oil control solenoid valve (see page
11_127]-.
Isthe VTC oil control solenoid valve OK?
YES-Go to step 4.
NO-CIean the VTC oil control solenoid valve, orreplace it (see page 11-'l27l.a
4. Remove the head cover, and check the cam chain
{see page 6-12).
ls the cam chain OK?
YES Go to slep 5.
NO Replace the cam chain (see page 6-12).1
5. Check the VTC actuator (see page 6-8).
ls the VTC actuator OK?
YES- U pdate the ECM if it does not have the tatest
soflware, or substitute a known-good ECI\4, thenrecheck (see page 11-6). lf the symptom/indicationgoes away with a known-good ECM, replace the
original ECM.I
NO- Replace the VTC actuator.l

WC OilControl Solenoid Valve Removal/Test
1. Remove the WC oilcontrol solenoid valve (A).
NOTE: lnstall the valve in the reverse order of
removal with a new o-ring (B), then check these
tlems:
Clean and dry the VTC oil control solenoid valve
mating surface.
Coat the O-ring with engine oil.
Do not install the VTC oilcontrol solenoid valve
while wearing fibrous gloves,
Be careful not to contaminate the cylinder head
openrng.
Check the VTC oil control solenoid valve filter for
clogging. lf it is clogged, replace the VTC oil control
solenoid valve.
Check the clearance between the port (advance
side) and the valve. The clearance (A) should be at
least 2.8 mm (1/8 in.).
Connect the battery positive terminal to VTC oil
control solenoid valve 2P connector terminal No. 2.
VTC OIL CONTROL SOLENOIDVALVE 2P CONNECTOR
Terminal side oJmale terminals
Connect the battery negative terminal to VTC oil
control solenoid valve 2P connector terminal No. 1,
then make sure the valve (A) opens fully.
BATTERY
11-127

VTEC/WC
1.
CMP Sensor A Replacement
Remove the air cleaner (see page 1 1-162).
Disconnect the CMP sensor A 3P connector.
Remove the CMP sensor A (A).
Installthe sensor in the reverse order of removal
with a new o-ring (B).
B-'-----'-l:,",14*
11-128
WEC Solenoid Valve Removal/
Inspection
1.Disconnect the VTEC solenoid valve 2P connector.
Measure resistance between VTEC solenoid valve
connector terminals No. 1 and No. 2.
Resistance: 14-30 Q
3. lf the resistance is within specifications, remove the
VTEC solenoid valve assemblv (A)from the
cylinder head, and check the VTEC solenoid valve
filter (B)for clogging. lf it is clogged, replace the
solenoid valve filter, the engine oilfilter, and the
engine oil.
6x1.0mm9.8 N.m (1.0 kgf.m, 7,2 lbf.ftl
L

ldle Control System
DTC Troubleshooting
DTC P0505: ldle Control System Malfunction
NOTE: lf DTC P1519 is stored atthe same time as DTC
P0505, troubleshoot DTC P1519 first, then recheck for
DTC P0505.
1. Start the engine. Hold the engine at 3,000 rpm with
no load (in neutral) until the radiator fan comes on,
then let it idle,
2. Checkthe engine speed at idle with no,load
conditions: headlights, blower fan, rear defogger,
radiator fan, and air conditioner off.
Is the engine running at 750t50 rpm?
YES - Intermittent failure, system is OK at this
trme.I
NO lf the idle speed is less than 700 rpm, go to
step 3; if it's 800 rpm or higher, go to step 4.
3. Disconnect the idle air control {lAC) valve3P
connector.
Does the engine speed increase or fluctuate?
YES- Check the idle speed {see page 1 1-138). lf the
idle will not adjust properly, clean the passage in
the throttle body, and then adjust the idle. I
NO- Replace the IAC valve.I
4. Turn the ignition switch OFF.
5. Remove the intake air duct from the throttle body.
6. Start the engine, and let it idle.
11-130
(
7. Put your fingers on the lower pon (A) inthethrottle
oooy.
Does the engine stall?
YES Checkthe idle speed (see page 11-138). lfit's
out of specification, replace the IAC valve.l
NO With the throttle valve completely closed,
check for vacuum leaks, and repair as necessary.l

ldle Gontrol System
't.
Alternator FR Signal Circuit Troubleshooting
Disconnect the alternator 4P connector from the
alternalor.
Turn the ignition switch ON {ll).
Measure voltage between ECM connector
terminals 424 and 813.
ECM CONNECTORS
2.
3.
A l31Pl
1 21345611 | 1.,'I
1011112,/56,/r8119l2C21
2312428129130
L(BRN/YEL)
ALTF(WHT
213 4t561
89ltal,/l/15
Wire side of female terminals
ls there about 5 V?
YES Go to step 4.
NO-Go to step 13.
4. Turn the ignition switch OFF.
5. Reconnect the alternator 4P connector.
6. Slan the engine. Hold the engine at 3,000 rpm with
no load (in neutral) until the radiator fan comes on,
then let it idle.
7. lvleasure voltage between ECM connector
terminals A24 and B 13.
Does the voltage decrease when the headlights
and rear window defogger arc tutned on?
YES The alternator FR signal is OK.l
NO-Go to step 8.
8. Turn the ignition switch OFF.
9. Disconnect ECM connector B (24P).
10. Disconnect the alternator 4P connector.
/REDI
11-134
'11. Connect alternator 4P con necto r term inal No.4 to
body ground with a jumper wire.
ALTERNATOR 4P CONNECTOR
12
ALTF34IWHT/RED)
JUMPER WIRE
12.
Wire side of female terminals
Check for continuity between body ground and
EClvl connector terminal 813.
ECM CONNECTOB B (24PI
Wire side of female terminals
ls there continuity?
YES-Testthe alternator (see page 4-22).1
NO Repair open in the wire between the ECM(B 13) and the alternator.l
Turn the ignition switch OFF.
Disconnect ECM connector B (24P).
\
13.
't 4.

ldle Control System
ldle Speed lnspection
NOTE:' Leave the idle air control (lAC) valve connecled.. Before checking the idle speed, check these items:- The malfunction indicator lamp (MlL) has not been
reported on.- lgnition timing- Spark plugs- Air cleaner- PCV system. Pullthe parking brake lever up. Start the engine, and
make sure the headlights are off.
1. Disconnect the evaporative emission (EVAP)
canister purge valve 2P connector.
2. Connect a tachometer (A)to the test tachometer
connector (B), or connect the Honda PGM Tester (C)
or an OBD ll scan tool to the data link connector(DLC) (D) located under the driver's side of the
dashboard.
11-138
4.
3.
5.
6.
Start the engine. Hold the engine at 3,000 rpm with
no load (in neutral) until the radiator fan comes on,
then let it idle.
Check the idle speed with no-load conditions;
headlights, blower fan, radiator fan, and air
conditioner off.
ldle speed should be: 750 t 50 rpm
Let the engine idle for 1 minute with the heater fan
switch on Hl and air conditioner on, then check the
idle speed.
ldle speed should be: 750 t 50 rpm
NOTE: lf the idle speed is not wilhin specification,
go to the Symptom Troubleshooting Index,
Reconnect the EVAP canister purge valve 2P
connector.