2003 HONDA CIVIC switch

4. Align the quick-connect fittings with the line (A).
and align the retainer (B) locking pawls with the
connector {C) grooves. Then press the quick-
connect fittings onto the line until both retainer
pawls lock with a clicking sound.
NOTE; lf it is hard to connect, put a small amount of
new engine oil on the line end.
Connection with new retainer:
Reconnection to existing retainer:
5. lvlake sure the connection is secure and that the
pawls are firmly locked into place; check visually
and by pulling the connector.
6. Reconnectthe negative cable to the battery, and
turn the ignition switch ON (ll). The fuel pump will
run for about 2 seconds, and fuel pressure will rise
Repeat 2 or 3 times, and check that there are no
fuel leaks.
11-151

Fuel Supply System
Fuel Gauge Sending Unit Test
Special Tools Required
Fuel sender wrench 07XAA-001010A
NOTE; For the fuel gauge system circuit diagram, referto the Gauges Circuit Diagram (see page 22-58||.
1. Checkthe No. 10 fUETER {7.5A)fuse in the under-
dash fuse/relay box before testing.
2. Do the gauge drive circuit check (see page 22-56|l.
' lf the fuel gauge needle sweeps from minimuni
to maximum position and then returns to the
minimum position. the gauge is OK. Go to step 3.. lf the fuel gau ge need le does not sweep from
minimum to maximum position position and
then return to the minimum position, replace thegauge assembly and retest.
3. Turn the ignition switch OFF.
4. Remove the rear seat cushion {see page 20-80).
5. Remove the access panel (A)from the floor.
6. Disconnect the fuel pump 5P connector {B).
-ztr
11-156
7. Measure voltage between fuel pump 5P connectorterminals No. 1 and No. 2 with the ignition switchON (ll). There should be battery voltage.
. lf the voltage is as specified, go to step 8.. lf the voltage is notasspecified,checkfor:
- an open in the YEUBLK or BLK wire.- poor ground (G551).
FUEL PUMP 5P CONNECTOR
Wire side of female terminals
Turn the ignition switch OFF. Remove the No. 9BACK UP (7.5A)fuse from the under-hood fuse/
relay box for at least 10 seconds, lhen reinstall it.
Install a 2 Q resistor between fuel pump 5P
connector lerminals No. 1 and No. 2, then turn the
ignition switch ON (ll).
FUEL PUMP 5P CONNECTOR
-VVV-
29RESISTOR,
=-a
{Y
\
//,(elrt \
\45/
{YEL/BLK)
Wire side of female terminals

10. Checkthatthe pointerof thefuel gauge indicates"F".
. lf the pointer does not indicate "F", replace the
ga uge.. lf the pointer indicates "F", inspect the fuel
gauge sending unit.
NOTE: The pointer of the fuel gauge retu rns to the
bottom of the gauge dial when the ignition switch
is OFF, regardless of the fuel level. -
11. Relieve the fuel pressure (see page 11-144\.
12. Remove the fuelfill cap.
13. Disconnect the quick-connect fittings from the fuel
pump.
14. Using the special tool, loosen the fuel tank unit
locknut (A).
A93Nm{9.5 ksf.m,69 lbf.ft}
15. Measure resistance between the No. 1 and No.2
terminals with the float at E (EN4PTY), 'l12 \HALF
FULL), and F {FULL) positions.
lf you do not get the following readings, replace the
fuel gauge sending unit {see page 1'1-163).
Float
Position
F'U2LOWE
Resistance
{0)
11
to 13
68,5
to 74.5
114.4
to 126.6
130
to 132
NOTE: Remove the No. 9 BACK UP (7.5A) fuse from
the under-hood fuse/relay box for at least 10
seconds after completing troubleshooting,
otherwise it may take up to 20 minutes for the fuel
gauge to indicate the correct fuel level.
11-157

Fuel Supply System
1.
4,
Low Fuel Indicator Test
Do the fuel gauge sending unit test (see page 11,
rcol.
. lf the system is OK, go to step 2.. lf the system has any malfunction, repair it.
Turn the ignition switch OFF. Remove the No. 9
BACK UP (10A) fuse from the under-hood fuse/
relay box for at least 30 seconds, then reinstall it.
Turn the ignition switch ON (ll) with the float at the
E (EMPry) position.
. lf the low fuel indicator is on, go to step 4.. lf the low fuel indicator is not on, refer to the low
fuel indicator Circuit Diagram (see page 22-58)
and check the circuit.
Turn the ignition switch OFF. Remove the No. 9
BACK UP (10A) fuse from the under-hood fuse/
relay box for at least 30 seconds, then reinstall it.
Lift the float above the LOW position.
. lf the lowfuel indicatorgoes off,the system is OK.. lf the low fuel indicator is still on, refer to the low
fuel indicator Circuit Diagram {see page 22-58),
and check the circuit.
11-158
\,

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
!

DTC Troubleshooting
DTC P0451: FTP Sensor Range/Performa nce
Problem
Special Tools Required
Vacuum Pump/Gauge, 0-30 in. Hg A973X-041-XXXXX
1. Remove the fuel fill cap.
2. Turn the ignition switch ON (ll)
3. l\4onitor fuel tank pressure (FTP) sensorvoltage
with the Honda PGM Tester, or medsure voltage
between ECM connectorterminals E4 and E14.
ECM CONNECTOR E 131P)
Wire side of female terminals
ls there about 2.5V?
YES-Go to step 4.
NO Replace the FTP sensor.I
Turn the ignition switch OFF.
Disconnect the hose between the EVAP two way
valve and the FTP sensor at the EVAP two way
valve end.
4.
5.
7.
8.
6. Connect a vacuum pump to the open end of the
hose.
Turn the ignition switch ON {ll).
l\4onitor FTP sensor voltage with the Honds PGM
Tester, or measure voltage between ECM
connector terminals E4 and E14, and carefully
squeeze the vacuum pump a little.
ECM CONNECTOR E 13lPI
Wire side of lemale terminals
The voltage should smoothly drop from about 2.5 V
to about 1.5 V. Stop applying vacuum when the
voltage drops to about 1.5 V or damage to the FTP
sensor may occur.
Does the voltage drop to about 1.5 V and hold?
YES Check for misrouted, leaking, or broken FTP
sensor vacuum lines. lf the vacuum lines are OK,
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 ECM, replace the
original ECM.I
NO Replace the FTP sensor. !
9.
11-171

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