2003 HONDA CIVIC Ignition switch

DTC Pl519: IAC Valve Circuit Malf unction
1. Resetthe ECM (see page 11-4).
2. Turn the ignition switch ON (ll)
ls DTC P 1519 indicated?
YES Go to step 3.
NO-lntermittent failure, system is OK at this time.
Check for poor connections or loose terminals at
the IAC valve and at the ECM.I
3. Turn the ignition switch OFF.
4. Disconnect the IAC valve 3P connector.
5. Turn the ignition switch ON (ll).
6. Measure voltage betlveen IAC valve 3P connector
terminal No. 2 and body ground.
IAC VALVE 3P CONNECTOR
IGP {YEL/BLK)
Wire side of female terminals
ls there battery voltage?
YES Go to step 7.
NO-Repair open in the wire between the IAC valve
and the PGM-Fl main relay 1.1
Turn the ignition switch OFF.
123
7.
8, Check for continuity between body ground and IAC
valve 3P connector terminal No. 1.
IAC VALVE 3P CONNECTOR
123
PG1 {BLK}
a.
Wire side of lemale terminals
Is there continuity?
YES-Go to step 9.
NO Repair open in the wire between the IAC valve
and G'101.1
Disconnect ECM connector A (31P)
Check for continuity between body ground and
ECM connector terminal A12.
ECM CONNECTOR A 131P)
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IACV {BLK/RED}
1,)
Wire side oJ Jemale terminals
ls there continuity?
YES-Repair short in the wire between the IAC
valve and the ECM (A12).1
NO Go to step 1 1.
9.
10.
LCOnI Ol
11-131

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!

A/G Signal Circuit Troubleshooting
Turn the ignition switch ON (ll).
Momentarily connect ECM connector terminals 424
and E18 with a jumper wire several times.
1.
2.
5.
Wire side of female terminals
ls there a clicking noise I rom the NC compressor
clutch?
YES Go to step 3.
NO-Go to step 6.
Sta rt the engine.
Turn the blower switch ON.
Turn the Ay'C switch ON.
Does the NC operate?
YES-The air conditioning signal is OK.I
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 €CM.l
6. Momentarily connect under-hood tuse/relay box
14P connector terminal No. 10 to body ground with
a jumper wire several times.
UNDER.HOOD FUSE/RELAY BOXI4P CONNECTOR
12356
1891011IJ14
ACC (RED)
JUMPER WIRE
Wire side of female terminals
ls there a clicking noise f rom the NC compressor
clutch?
YES- Repair open in the wire between the ECM(E'18) and the Ay'C clutch relay.l
NO- Check the A/C system for other symptoms.l
11-133

ldle Gontrol System
't.
Alternator FR Signal Circuit Troubleshooting
Disconnect the alternator 4P connector from the
alternalor.
Turn the ignition switch ON {ll).
Measure voltage between ECM connector
terminals 424 and 813.
ECM CONNECTORS
2.
3.
A l31Pl
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ALTF(WHT
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Wire side of female terminals
ls there about 5 V?
YES Go to step 4.
NO-Go to step 13.
4. Turn the ignition switch OFF.
5. Reconnect the alternator 4P connector.
6. Slan the engine. Hold the engine at 3,000 rpm with
no load (in neutral) until the radiator fan comes on,
then let it idle.
7. lvleasure voltage between ECM connector
terminals A24 and B 13.
Does the voltage decrease when the headlights
and rear window defogger arc tutned on?
YES The alternator FR signal is OK.l
NO-Go to step 8.
8. Turn the ignition switch OFF.
9. Disconnect ECM connector B (24P).
10. Disconnect the alternator 4P connector.
/REDI
11-134
'11. Connect alternator 4P con necto r term inal No.4 to
body ground with a jumper wire.
ALTERNATOR 4P CONNECTOR
12
ALTF34IWHT/RED)
JUMPER WIRE
12.
Wire side of female terminals
Check for continuity between body ground and
EClvl connector terminal 813.
ECM CONNECTOB B (24PI
Wire side of female terminals
ls there continuity?
YES-Testthe alternator (see page 4-22).1
NO Repair open in the wire between the ECM(B 13) and the alternator.l
Turn the ignition switch OFF.
Disconnect ECM connector B (24P).
\
13.
't 4.

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.
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16.
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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

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
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7-
z
ECM CONNECTOR E 131P}

FuelSupply System
(
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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.