2003 HONDA CIVIC Circuit

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.
12345617l 189
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

Brake Pedal Position Switch Signal Circuit Troubleshooting
1. Check the brake lights.
Are the brake lights on without pressing the brakepedal?
YES Inspectthe brake pedal position switch(see page 19-6).I
NO Go to step 2.
2. Press the brake pedal.
Do the brake lights come on?
YES-Go to step 3.
NO Go to step 4.
3. Measure voltage between ECM connector
terminals A24 and E22 with the brake pedal
presseo.
ls there battery voltage?
YES-The brake pedal position switch signal is
oK,I
NO Repair open in the wire between the Eclvl(E22) and the brake pedal position switch.l
Wire side of lemale terminals
4. Inspect the No. 7 HORN, STOP (15A) fuse ln the
under-hood fuse/relay box.
ls the tuse OK?
YES- Repair open in the wire between the brake
pedal position switch and the No.7 HORN, STOP( l5A) fuse, Inspect the brake pedal position switch(see page 19-10).1
NO Repair short in the wire between the ECM(E22) and the No.7 HORN, STOP (15A)fuse.
Replace the No.7 HORN, STOP (15A)fuse.t
11-137

Fuel Pump Circuit Troubleshooting
lf you suspect a problem with the fuel pump, check that
the fuel pump actually runs; when it is on, you will hear
some noise if you listen to the fuel fill port with the fuel
fill cap removed. The fuel pump should run for 2
seconds when the ignition switch is first turned on. lf
the fuel pump does not make noise, check as follows:
1. Turn the ignition switch OFF.
2. Remove the glove box {see page 20-63), then
remove the PGM-FI main relay 2 (A).
Turn the ignition switch ON {ll).
Measure voltage between PGM-Fl main relay 2 5P
connector lerminal No. 5 and body ground.
PGM.FI MAIN RELAY 25P CONNECTOR
IGPl(YEL/BLK}
Wire side of female terminals
ls there battery voltage?
YES-Go to step 5.
NO Repair open in the wire between the PGM'Fl
main relay 1 and the PGM-Fl main relay 2.t
3.
5. N4easure voltage between PGM-Fl main relay 2 5P
connector terminal No. 1 and body ground.
PGM.FI MAIN RELAY 25P CONNECTOR
Wire side oJ female terminals
ls there battery voltage?
YES Go to step 6.
NO Repair open in the wire between the under-
dash fuse/relay box and PGM-Fl main relay 2.1
6. Turn the ignition switch OFF.
7. Disconnect ECM connector E (31P).
8. Check for continuity between PGM-FI mainrelay2
5P connector terminal No. 3 and ECM connector
terminal E1.
PGM-FI MAIN RELAY 2 5P CONNECTOB
Wire side of female terminals
ls there continuity?
YES-Go to step 9.
NO-Repair open in the wire between the PGM Fl
main relay 2 and the ECM (E1).1
IMOFPR(GBN/YEL)
(cont'd)
11-141
Et2lFtxm
7-
z
ECM CONNECTOR E 131P}

FuelSupply System
(
(
L
10.
1'].
Fuel Pump Circuit Troubleshooting (cont'dl
Reinstallthe PGM-Fl main relay 2.
Turn the ignition switch ON (ll).
Measure voltage between ECI\4/PCM connector
terminal E1 and body ground.
ECM CONNECTOB E {31P)
ls there battety voltage?
YES Go to step 12.
NO-Replace the PGM-Fl main relay 2.1
Turn the ignition switch OFF.
Reconnecl ECM connector E (31P).
Turn the ignition switch ON (ll), and measure
voltage between ECM connector terminal E1 and
body ground within the first 2 seconds after the
ignition switch was turned ON (ll).
ECM CONNECTOR E (31PI
13.
14.
Wire side of female terminals
Wire side of female terminals
11-142
t5.
to.
11.
18.
ls there battery voltage?
YES U pdate the ECM if it does not have the latest
so{1ware, 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 Go to step 15.
Turn the ignition switch OFF.
Remove the rear seat cushion (see page 20-80).
Remove the access panel from the floor.
Measure voltage between fuel pump 5P connector
terminal No. 5 and body ground within the first 2
seconds after the ignition switch was turned ON (ll).
FUEL PUMP 5P CONNECTOR
wire side oI female terminals
ls there battery voltage?
YES Go to step 24.
NO-Go to step 19.
Turn the ignition switch OFF.
Remove the PGM-Fl main relay 2.
19.
20.

Fuel Pressure Test
Special Tools Required. Fuel pressure gauge 07406-0040004. Fuel pressure gauge sel 07ZAJ-S5A0100
1. Relieve the fuel pressure (see page 1'1-144).
2. Disconnect the quick-connect fitting (A). Aftach the
fuel pressure gauge set and fuel pressure gauge.
Start the engine and let it idle.
. lf the engine starts, goto step 5.. lf the engine does not start, goto step 4.
Check to see if the fuel pump is running: listen to
the fuel fill port with the fuel fill cap removed. The
fuel pump should run for 2 seconds when the
ignition switch is first turned on.
. lf the pump runs, go to step 5.. lf the pump does not run, do the fuel pump circuit
troubleshooting (see page 1 1-1 41 ).
Read the pressure gauge. The pressure should be
320-370 kpa (3.3-3.8 kgf/cm', a7-52 psi)
. lf the pressure is OK, the test is complete.. lf the pressure is out of specification, replace the
fuel pressure regulator and the fuel filter (see
page 11-152), then recheck the fuel pressure.
5.
11-145

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

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
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