2003 HONDA CIVIC Control

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

ldle Gontrol System
Component Location Index
TE'
IDLE AIR CONTROL {IAC) VALVETroubleshooting, page 1 1-'131
11-129

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 Control System
(DTC Troubleshooting (cont'd)
11. Connect IAC valve 3P connector terminal No.3 to
body ground with a jumper wire.
IAC VALVE 3P CONN€CTOR
IACV IBLK/REO}
JUMPER WIRE
Wire side of female terminals
Check for continuity between ECM connector
terminalAl2 and body ground.
ECM CONNECTOR A 131P)
Wire side of female terminals
ls there continuity?
YES Go to step 13.
NO-Repair open in the wire between the IAC valve
and rhe EcM (A12).r
Reconnect the IAC valve 3P connector.
Turn the ignition switch ON (ll).
13.
14.
11-132
15. Measure voltage between body ground and ECM
connector terminal A12.
ECM CONNECTOR A 131P}
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IACV IBLK/RED)
Wire side ol female terminals
I s there battery voltage?
YES-Update the ECI\4 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 ECI\4.1
NO-Replace the IAC valve.I!

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
Electrical Power Steering (EPSI Signal Circuit Troubleshooting (cont'd)
9. Measure voltage between EPS control unitterminal
No.l7 and body ground.
EPS CONTROL UNIT 2OP CONNECTOR
Wire side of female terminals
ls there battety voltage?
YES-Substitute a known-good EPS control unit
and recheck.I
NO- Repair open in the wire between the ECM(E 16) and the EPS control unit.l
Turn the ignition switch OFF.
Disconnect the EPS control unit 20P connector.
Turn the ignition switch ON (ll).
10.
I 'I.
12.
11-136
'13. l\4easure voltage between EPS control unitterminal
No. 17 and the body ground.
EPS CONTROL UNIT 2OP CONNECTOR
Wire side of female terminals
ls there battery voltage?
YES Substitute a known-good EPS control unit
and recheck.l
NO-Go to step 14,
Turn the ignition switch OFF.
Disconnectthe ECM connector E {31P).
Check for continuity between body ground and
ECI\4 connector terminal E16.
ECM CONNECTOR E {31PI
14.
t5_
16.
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56./182A21
2223zi ./29 30ol
EPSLD{LT GRN/BLK)
a,
Wire side ot Iemale terminals
lsthere continuity?
YES Repair short in the wire between the ECN4(E 16) and the EPS control unit.l
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/indicationgoes away with a known-good ECM, replace the
original ECM.I

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.

Intake Air System
Component Location Index
INTAKE AIR BYPASS CONTROLTHERMAL VALVETest, page 1'1-161
i l.
AIR CLEANERReplacement, page 1 1'162AIR CLEANER ELEMENTReplacement, page 1 1-162
THROTTLE CABLEAdjustment, page 1 1-163Removal/lnstallation, page 1 1-164THROTTLE BODYTest, page l'l-160Removal/lnstallation, page 1 1-165Disassembly/Reassembly, page 1 1 166
11-159