2003 HONDA CIVIC engine

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
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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*
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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

A/G Signal Circuit Troubleshooting
Turn the ignition switch ON (ll).
Momentarily connect ECM connector terminals 424
and E18 with a jumper wire several times.
1.
2.
5.
Wire side of female terminals
ls there a clicking noise I rom the NC compressor
clutch?
YES Go to step 3.
NO-Go to step 6.
Sta rt the engine.
Turn the blower switch ON.
Turn the Ay'C switch ON.
Does the NC operate?
YES-The air conditioning signal is OK.I
NO Update the ECM if it does not have the latest
software, or substitute a known-good ECM. then
recheck (see page 11-6). lf the symptom/indication
goes away with a known-good ECM, replace the
original €CM.l
6. Momentarily connect under-hood tuse/relay box
14P connector terminal No. 10 to body ground with
a jumper wire several times.
UNDER.HOOD FUSE/RELAY BOXI4P CONNECTOR
12356
1891011IJ14
ACC (RED)
JUMPER WIRE
Wire side of female terminals
ls there a clicking noise f rom the NC compressor
clutch?
YES- Repair open in the wire between the ECM(E'18) and the Ay'C clutch relay.l
NO- Check the A/C system for other symptoms.l
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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.

15. Check for continuity between body ground and
ECIM connector terminal 813.
ECM CONNECTOR B I24P}
Wire side of female terminals
ls there continuity?
YES Repair short in the wire between the ECM
(813) and the alternator.l
NO Update the ECM if it does not have the latest
software, or substitute a known-good ECM, then
recheck lsee page 1 1-6). lf the symptom/indication
goes away with a known-good ECM, replace the
original ECM.I
Electrical Power Steering (EPSI
Signal Circuit Troubleshooting
Turn the ignition switch ON (ll).
l\4easure voltage between ECM connector
terminals 424 and E16.
1.
2.
3.
4.
5.
Wire side of female terminals
ls there battery voltage?
YES Go to step 6.
NO Go to step 3.
Start the engine.
Turn the steering wheel lo the full lock position.
l\4easure voltage between ECM connector
terminals A24 and E16.
ls there momentaty battery voltage?
YES The EPS signal is OK.t
NO Go to step 10.
6. Turn the ignition switch OFF.
7. Disconnect the EPS control unit 20P connector.
8. Turn the ignition switch ON (ll).
(cont'd)
11-135

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.

ECM ldle Learn Procedure
The idle learn procedure must be done so the ECM can
learn the engine idle characteristics.
Do the idle learn procedure whenever you do any of
these actions:. Disconnect the battery.
Replace the ECM or disconnect its connector.
Reset the ECM.
NOTE: Erasing DTCS with the Honda PGM Tester
does not require you to do the idle learn procedure.
Remove the No.6 ECU {ECM) ( 15A) fuse from the
under-hood fuse/relay box.
Remove the No.19 baftery (80A) fuse from the under-
hood fuse/relay box.
Remove PGM-FI main relay 1.
Remove any of the wires from the under-hood fuse/
retay Dox.
Disconnect any of the connectors from the under
hood fuse/relay box.
Disconnect the connector between the engine
compartment wire harness and ECM wire harness.
Disconnect the G2 terminal from the transmission
ho u srng.
Disconnectthe G'l terminal from the body.
Disconnectthe G101 terminal from the cylinder head
cover.
Procedure:
To complete the idle learn procedure, do this:
1. Make sure all electrical items (Ay'C, audio, rear
defogger, l:ghts, etc.,) are off.
2. Start the engine, and hold it at 3,000 rpm with no
load {in neutral) until the radiator fan comes on, or
until the engine coolanttemperature reaches 194"F(90'c).
3. Let the engine idle for about 5 minutes with the
throttle fully closed.
NOTE: lf the radiator fan comes on, do not include its
running time in the 5 minutes.
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