2003 HONDA CIVIC Idle air control

Evaporative Emissions (EVAP) Control
System Monitor and Readiness code
NOTE:
All readiness code are cleared when the batterV is
disconnected or when the ECM is cleared with the
OBD ll scan tool or Honda PGM Tester.
The enable criteria must be repeated if the intake air
temperature (lAT) drops lower than 36'F (20"C) from
its value at engine $an up.
Enable Criteria
At engine start up, ECT and IAT are higher than 32'F(0"C) , but lower than 95'F (35"C).
At engine start up, the ECT and IAT are within 12'F(7'C) of each other.
Procedure
1. Connect the scan tool to the vehicle's data link
connector (DLC), and bring up the tool's generic
OBD ll mode.
2. Start the engine.
3. Test-drive the vehicle under stop-and-go conditions
with short periods of steady cruise. After about
2.5 miles (1.6 km), the readiness code should
switch f rom incomplete to complete.
4. lf the readinesscode isstill setto incomplete, check
for a temporary DTC. lf there is no DTC, one or
more of the enable criteria were probably not met;
repeat the procedure.
Air Fuel Ratio (A/Fl Sensor Monitor and
Readiness Code
NOTE:. Do not turn the ignition switch off during the
orocedure.. All readiness codes are cleared when the baftery is
disconnected or when the ECM is cleared with the
OBD ll scan tool or Honda PGM Tester.
Enable Criteria
ECT at 140'F (60"C) or higher.
Procedure
1. Connect the scan toolto the vehicle's data link
connector (DLC), and bring up the tool's generic
OBD ll mode.
2. Start the engine.
3. Test-drive the vehicle under stop-and-go conditions
with short periods of steady cruise. During the
drive, decelerate (wirh the throttle fully closed) for
5 seconds. After about 3.5 miles (2.2 km). the
readiness code should switch from incomDlete to
complete.
4. lfthereadinesscodeisstill set to incomplete, check
for a temporary DTC. lfthere is no DTC, the enable
criteria was probably not meU repeat the procedure.
Air/Fuel Ratio (A/Fl Sensor Heater Monitor
Readiness Code
NOTE; All readiness codes are cleared when the battery
is disconnected or when the ECM is cleared with the
OBD ll scan tool or Honda PGM Tester,
Procedure'1. Connect the scan tool to the vehicle's data link
connector {DLC), and bring up the tool's generic
OBD ll mode.
2. Start the engine, and let it idle for 1 minute. The
readiness code should switch from incomplete to
comDlete.
3. lf the readiness code is still set to incomplete, check
for a temporary DTC. lf there is no DTC, repeat theproceoure.
(cont'd)
11-47

VTEC/VTC
DTG Troubleshooting
DTC P0010: WC Oil Control Solenoid ValveMalfunction
1. Resetthe ECM (see page 11-4).
2. Start the engine. Hold the engine at 3,000 rpm withno load (in neutral) until the radiator fan comes on,
then let it idle.
3. Test-drive at a steady speed between 20-40 mph(30-60 km/h) for 10 minutes.
ls DTC P0010 indicated ?
YES Go to step 4.
NO- Intermittent failure, system is OK at this time.
Check for poor connections or loose terminals at
the VTC oil control solenoid valve and at theECM.I
4. Turn the ignition switch OFF.
5. Disconnect the ECM connector B {24P).
6. Measure resistance between ECrU connector
terminals B1 and 823.
ECM CONNECTOR B I24P)
Wire side of female terminals
ls there 6.75 8.25 Q ?
YES Go to step 1 1.
NO Go to step 7.
7. Disconnect the VTC oil control solenoidvalve2P
connector.
11-118
8. Measure resistance between VTC oil control
solenoid valve 2P terminals No. 1 and No. 2.
VTC OIL CONTAOL SOLENOIDVAI"VE 2P CONNECTOB
Termina sid6 otmate termina s
ls there 6.75 8.25 Q ?
YES-Go to step L
NO-Replace the VTC oil control solenoid valve(see page 11-1271.a
9. Connect VTC oil control solenoidvalve2P
connector terminals No. 1 and No. 2 to bodyground with a jumperwire individually.
wc otl coNTBoL sotENotoVALVE 2P CONNECTOR
-4-t1t2l
wc I lwc*tBr-K/wHT) | liELU/WHT)JUMPER WTREI IJUMPEn W|RE
Wire side of16male te.minats
10. Check for continuity between ECM connector
terminals B1 and 823 and body ground individually.
ls there continuity?
YES Go to step 11.
NO- Repair open in the wire between the ECM (B 1,
B23) and the VTC oil control solenoid valve.I
\

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
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.

Throttle Body Removal/lnstallation
NOTE:' Do not adjust the throttle stop screw.. Afterreassembly,adjustthethrottlecable{seepagell-163) and the cruise control cable (see page 4-45).. The throttle position (TP) sensor is not removable.
THROTTLELEVER
There should beno clearance
THROTTLE CABLE
MANIFOLDABSOLUTE PRESSURE{MAP} SENSOR
22Nm(2.2 kgt.m, 16 lbf.ft)
EVAPORATIVE EMISSION {EVAPICANISTER PURGE VALVE
IDLE AIR CONTROL{IACI VALVE
11-165

28.
29.
ls thete continuity?
YES-Go to step 28.
NO-Replace the EVAP canister vent shut valve (A)
and o-ring (B).1
Disconnect ECM connector E (31P).
Check for continuity between EVAP canister vent
solenoid valve 2P connector terminal No. 2 and
body ground.
EVAP CANISTER VENT SHUTVALVE 2P CONNECTOR
Wire side o{ female terminals
ls there continuity?
YES-Repair short in the wire between the EVAP
canister vent shut valve and the ECM (E21).1
NO Update the ECM if it does not have the latest
soflware, 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 ECM.I
30.
Vacuum Hoses and Connections Test
Do the fuel tank vapor control valve test (see page
1 1-187).
ls the fuel tank vapot control valve OK?
YES-Go to step 31.
NO Replace the fueltank vapor control valve.l
Tighten the fuel cap 3 "clicks", then monitorthe
FTP sensor readings with the Honda PGM Tester.
Start the engine. and let it idle for 5 minutes.
Check the FTP sensor readings.
ls the reading above 0.5 kpa (4 mm Hg, 0.16 in.
Hg) pressure, or about 3 V?
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/indication
goes away with a known-good ECfvl, replace the
original ECM.t
NO Check the following parts for leaks:l
. Fueltank (A)
. Fuel fill cap (B)
. Fuel fill pipe (C)
. Fueltank vapor control valve(D). Fueltank vapor recirculation valve (E)
. Fueltank vapor recirculation tube (F)
. Fueltank vapor signaltube (G)
. Fueltank vapor control venttube(H). FTP sensor (J)
- Repair or replace any leaking parts.
5t.
11-179

28. Connect the transmission ground cable (A).
8 x 1.25 mm
B
22 N.m (2.2 kgf.m, 16lbf.ft)
[---.-.---e
e
6x1,0mm9.8 N.m{1.0 kgl m. 7 lbf ftl
29.
30.
8x125mm22Nm12.2 kgt m, 16 lbf ft)
lnstall the battery tray (B).
Installthe intake air duct (see step 36 on page 5-14).
Installthe air cleaner housing (see step 39 on page
5-15).
Installthe intake manifold cover (see step 41 on
page 5-15).
Install the battery. Connectthe positive (+) cable
first, then the negative (-)cable to the battery.
Reflllthe transmission fluid (see page 13-3).
Test-drive the vehicle.
Check the clutch operation.
Check the front wheel alignment (see page 18-4).
Enter the anti-theft code for the radio, then enter
the customer's radio station presets.
Do the engine control module (ECM) idle learn
procedure (see page 11-139).
32.
33.
34.
35.
36.
31.
38.
39.
13-13