2003 HONDA CIVIC Body

Intake Air System
Throttle Body Test
NOTE:. Do not adjust the throttle stop screw. lt is preset at the
factory.. lf the malfunction indicator lamp (MlL) has been
reported on, check for diagnostic trouble codes(DLCS) (see page 11 3).
1. With the engine off, check the throttle cable
movement. The cable should move without binding
or sticking.
. lf lhe cable moves OK, goto step 2.. lf the cable binds or sticks, check it and its routing.. lf the cable isfaulty, reroute itor replace itand
adjust it (see page 11-163), then go to step 2.
2. l\4ove the throttle lever by hand to see if the throftle
valve and/or shaft are too loose or too tight.
. lf there is excessive play in the throttle valve
shaft, or any binding in the throttle valve at the
fully closed position, replace the throttle body.. lf thethrottlevalve and shaft are OK, goto step3.
3. Connect the scan toolto the DLC.
Turn the ignition switch ON (ll).
Check the throttle position with the scan tool. The
reading should be about 10% when the throttle is
fully closed and about 90% when the throttle is fully
openeo.
. lf the throttle position is correct, the throttle body
is OK.. lf thethrottle position is notcorrect, replace the
throttle body.
5.
11-160
!

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

Intake Air System
Throttle Body Disassembly/Reassembly
EVAPORATIVE EMISSION {EVAP)CANISTER PURGE VALVE
A
V
2 N.m{0.2 kgt m, 1 lbf.ft)
3.5 N.m(0.35 kgf m.2.5lbf ft)
MAP SENSOR
THROTTLE BODY
L
TP SENSOR
11-166

PCV System
DTC Troubleshooting
DTC P1505: PCV Air Leakage
1. Reset the ECM (see page 11-4).
2. Start the engine. Hold the engine at 3,000 rpm with
no load (in neutral) until the radiator fan comes on
3. Let the engine idle tor al least 40 seconds with the
throttle fully closed.
4. Check for a DTC P1505 with the scan tool
ls DTC P1505 indicated?
YES-Check these parts for vacuum leaks l
. PCV valve. PCV hose. EVAP canister purge valve
. Throttle body. Brake booster hose
NO - Intermittent failure, system is OK at this
time.l
11-168

EVAP System
DTC Troubleshooting (cont'd)
DTC P0452: FTP Sensor Circuit Low Voltage
1. Check the vacuum lines at the FTP sensor for
misrouting, leakage. breakage, or clogging.
Are the vacuum lines OK?
YES Go to step 2.
NO Repair or replace vacuum lines as
necessary. I
2. Reset the ECM (see page 11-4).
3. Remove the fuelfill cap.
4. Turn the ignition switch ON (ll)
5. Monitor FTP sensor voltage with the Honda PGM
Tester, or measure voltage between body ground
and ECM connector terminal E14.
ECM CONNECTOR E 131PI
1 2t3t45o/89
././114tc61./182C21
22123241 t26271/ 2931
TP (LT GRN)
Wire side of female terminals
ls thete about 2.5 V?
YES- Intermittent failure, system is OK at this time.
Check for poor connections or loose terminals at
the FTP sensor and at the ECrM.l
NO Go to step 6.
11-172
6. Turn the ignition switch OFF.
7. Reinstallthe fuel fill cap.
8. Disconnect the FTP sensor 3P connector.
9. Turn the ignition switch ON (ll)
10. Measure voltage between FTP sensor 3P connector
terminals No. 1 and No.2.
FUEL TANK PRESSURE SENSOR 3P CONNECTOR
VCgl {YEL/BLU}
Wire side of female terminals
ls there about 5 V?
YES Go to step 1 '1.
NO-Repair open in the wire between the FTP
sensor and the ECM {E5).1

't2.
13.
14.
11. Measure voltage between FTP sensor 3P connector
terminals No. 2 and No.3.
FUELTANK PRESSUBE SENSOR 3P CONNECTOR
FTP (LT GBN)
Wire side of femaleterminals
ls there about 5 V?
YES - Replace the FTP sensor. t
NO-Go to step 12.
Turn the ignition switch OFF.
Disconnect ECM connector E (31P),
Check for continuity between FTP sensor 3P
connector terminal No. 3 and body ground.
FTP SENSOR 3P CONNECTOB
FTP (LT GRNI
Wire side of femalelerminats
ls there continuity?
YES Repair short in the wire between the FTP
sensor and the ECI\4 {E14).I
NO-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 EClvl, replace the
original ECM.I
DTC P0453: FTP Sensor Circuit High Voltage
1. Check the vacuum lines at the FTP sensor for
misrouting, leakage, breakage, or clogging.
Are the vacuum lines OK?
YES-Go to step 2.
NO Repair or replace vacuum lines as
necessary.I
2. Reset the ECM {see page 11'4).
3. Remove the fuel fill cap.
4. Turn the ignition switch ON (ll).
5. lvlonitor FTP sensor voltage with the Honda PGM
Tester, or measure voltage between body ground
and ECM connector terminal E'14.
ECM CONNECTOR E 131PI
112134567I9
56/ t182C21
242il./29 3031
TP {LT GRN}
Wire side of female terminals
Is there about 2.5 V?
YES Intermittent failure, system is OK at this time.
Check for poor connections or loose terminals at
the FTP sensor and at the ECM.I
NO Go to step 6.
{cont'd)
11-173

EVAP System
DTC Troubleshooting (cont'd)
8. Check for continuity between EVAP canister purge
valve 2P connenctor terminal No. 2 and body
grou no.
EVAP CANISTER PURGEVALVE 2P CONNECTOR
Wire side of female terminals
ls there continuity?
YES Go to step 9.
NO Replace the EVAP canister purge valve.l
Disconnect ECM connector B (24P).
Check for continuity between EVAP canister purge
valve 2P connector terminal No. 2 and body ground.
EVAP CANISTER PURGEVALVE 2P CONNECTOR
PCS{YEL/BLU)
Wire side of female terminals
ls there continuity?
YES Repair short in the wire between the EVAP
canister purge valve and the ECI\4 {821).1
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 ECM.I
9.
10.
12
'.\'
11-176
v
F-
A973X-041-XXXXX
EVAP Bypass Solenoid Valve Test
1 1 , Disconnect both vacuum hoses from the EVAP two
way valve (A), and connect a vacuum pump to the
canister port on the EVAP two way valve.
Turn the EVAP bypass solenoid valve on with the
Honda PGM Tester, or connect ECM connecter
terminal E20 to body ground with a jumper wire.
ECM CONNECTOR E 131P)
12345617l 189
456/ 1182C21
22t2?24z7l./29
JUMPERWIRE
2WBS(BLU/RED}
13.
14.
Wire side of female terminals
Turn the ignition switch ON (ll).
Apply vacuum to the hose.
Does the valve hold vacuum?
YES-Go to step 15,
NO Go to step 20.

15.
to.
Turn the ignition switch OFF.
Disconnect the EVAP bypass solenoid valve 2P
connecror.
Check for continuity between EVAP bypass
solenoid valve 2P connector terminal No. 2 and
body ground.
17.
EVAP BYPASS SOLENOIDVALVE 2P CONNECTOR
'18.
Wire side oI Iemale terminals
ls there continuity?
YES Go to step 18.
NO-Repair open in the wire bet\iveen the EVAP
bypass solenoid valve and the ECM (E20).1
Turn the ignition switch ON (ll).
2
tG'l
'19. Measure voltage between EVAP bypass solenoid
valve 2P connector terminal No. 1 and body ground.
EVAP BYPASS SOLENOIDVALVE 2P CONNECTOR
{BLK/ORN)
Wire side ol lemale terminals
ls there battery voltage?
YES Replace the EVAP two way/bypass solenoid
valve (A).1
NO-Repair open in the wire between the EVAP
bypass solenoid valve and the No. 4 ACG (10A)
fuse.l
{cont'd)
11-177