2003 HONDA CIVIC Circuit

PGM-FI System
MIL Circuit Troubleshooting (cont'dl
37. lvleasure voltage between ECM/PCM connector
terminal E7 and body ground.
ECM CONNECTOR E {31PI
Wire side of female terminals
ls there battery voltage?
YES Go to step 42.
NO Go to step 38.
Turn the ignition switch OFF.
Remove the PGM-FI main relay 1
38.
39.{A}
-A
MRLY
11-102
40. lvleasure voltage between PGN4-Fl main relay 1 4P
connector terminal No. 4 and bodv qround.
PGM-FI MAIN RELAY 1ilP CONNECTOR
41.
ls there battery voltage?
YES-Go to step 41.
NO Repair open in the wire between the No. 6
ECU (ECM) (15A) fuse and the PGfM-Fl main relay 1.
I
Check for continuity between PGM-FI main relay 1
4P connector terminal No. 3 and ECM connector
terminal E7.
PGM.FI MAIN RELAY 14P CONNECTOR
\
ECM CONNECTOR E 131PI
ls there continuity?
YES-Testthe PGM-Fl main relay 1 (see page 22-
51 ). lf the relay is 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*Repair open in the wire between the PGM-FI
main relay 1 and the ECM (E7).1
Wire side ot lemale terminals
MRLY (RED/YEL)
MRLY (RED/YEL)
Wire side of female terminals

PGM-FI System
MIL Circuit Troubleshooting (cont'dl
51. Measure voltage between body ground and ECM
connector terminals 44, A5, 423, and 424
individuallv.
ECM CONNECTOR A 131P)
PG2 (BLK) PG1 IBLKI
Wire side of female terminals
ls there morc than 1.0 V ?
YES Go to step 52.
NO-Repair open in the wire(s) that had more than
1.0 V between G 10'l and the ECM (A4, A5, A23,
A24l.a
Measure voltage between body ground and ECM
connector terminal 421.
ECM CONNECTOR A 131P)
Wire side of female terminals
ls there about 5 V?
YES-Go to step 60.
NO-Go to step 53.
11-104
53.
54.
Turn the ignition switch OFF.
Disconnect the manifold absolute pressure (MAP)
sensor 3P connector.
Turn the ignition switch ON (ll).
Measure voltage between body ground and ECM
connector terminal A21.
ECM CONNECTOR A {31P)
Wire side of female terminals
ls there about 5 V?
YES Replace the MAP sensor.l
NO Go to step 57.
Turn the ignition switch OFF.
Disconnect ECM connector A (31P).
55.
56.
\
57.
58.

PGM-FI System
67.
MIL Circuit Troubleshooting (cont'd)
Check for continuity between ECIM connector
terminal A20 and body ground.
ECM CONNECTOR A (31P)
rl2l3145ot/9
10t1121,/ 1,/1516ta,92A21
22 '3241 12526n
o
Wire side of female terminals
ls there continuity?
YES Repair shon in the wire between the ECN4
{A20) and the TP sensor, or repair short in the wire
between the ECM (A8) and the knock sensor. t
NO Update the ECM if it does not have the latest
software. or substitute a known-good ECM, then
recheck (see page l1-6). lf the symptom/indication
goes away with a known-good ECM, replace the
original ECM.t
vcc2{YEL/BLU}
11-106
68. Measure voltage between body ground and ECM
connector terminal E5.
ECM CONNECTOR E (31PI
Is there about 5 V?
YES U pdate 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 EClvl, replace the
original ECM.t
NO-Go to step 69.
Turn the ignition switch OFF.
Disconnect the fuel tank pressure (FTP) sensor 3P
connector.
Turn the ignition switch ON (ll).
69.
70.
11.
Wire side of female terminals

DLC Circuit Troubleshooting
lf the ECM does not communicate with the OBD ll scan
tool, Honda PGfM Tester, or l/M test equipment, do this
troubleshooting procedure.
1. Measure voltage between DLC terminal No. 16 and
body ground.
DATA LINK CONNECTOR {DLCI
(WHT/RED)
Terminal side of lemale terminals
ls therc battery voltage?
YES-Go to step 2.
NO-Repair open in the wire between DLC terminal
No. 16 and the No. 9 BACK UP (7.5 A) fuse in the
under-hood f use/relay box. I
Measure voltage between DLC terminals No. 4 and
No. 16.
DATA LINK CONNECTOR (DLCI
Terminal side of Jemale terminals
Is there battery voltage?
YES Go to step 3.
NO Repair open in the wire between DLC terminal
No. 4 and body ground.l
4.
5.
3. Measure voltage between DLC terminals No. 5 and
No. 16.
DATA LINK CONNECTOR {DLC)
Terminal side of female terminals
ls there battery voltage?
YES Go to step 4.
NO- Repair open in the wire between DLC terminal
No. 5 and the ECM (E3). t
Turn the ignition switch ON {ll).
Measure voltage between DLC terminals No.5 and
No.7.
DATA LINK CONNECTOR {DLCI
Terminal side of lemale terminals
ls there 8.5 V or more?
YES Go to step 10.
NO Go to step 6.
6. Turn the ignition switch OFF.
(cont'd)
11-109

PGM-FI System
DLC Circuit Troubleshooting {cont'dl
7. Disconnect EClvl connector E (31P). Make sure the
OBD llscan tool or Honda PGM Tester is
disconnected from the DLC.
8. Check for continuity between DLC terminal No. 7
and body ground.
DATA LINK CONNECTOR IDLC)
Ierminal side of female terminals
ls there continuity?
YES-Repair short to ground in the wire between
DLC terminal No. 7 and the ECM {E23). After
repairing the wire, check the DTC with the OBD ll
scan tool/Honda PGM Tester, and go to the DTC
Troubleshooting index. I
NO Go to step 9.
Check for continuity between DLC terminal No. 7
and ECM terminal E23,
ECM CONNECTOR E {31PI
Terminal side of female terminals
9.
K-LINE {LT BLU)
DATA LINK CONNECTOR
11-110
10.
1 'I.
tJ.
ls there continuity?
YES U pdate 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 ECI\4.I
NO Repair open in the wire between DLC terminal
No.7 and the ECM {E23). After repairing the wire,
check the DTC with the OBD ll scan tool/Honda
PG l\4 Tester, and go to the DTC Troubleshooting
Index.l
Turn the ignition switch OFF.
Disconnect ECI\4 connector E (31P). l\4ake sure the
OBD ll scan tool or Honda PGM Tester is
disconnected from the DLC.
Turn the ignition switch ON (ll).
Measure voltage between DLC terminals No. 5 and
No.7.
DATA LINK CONNECTOR {DLC}
Terminal side of female terminals
Is there 0 V?
YES Update the ECM if it does not have the latest
software, or substitute a known-good ECI\4, then
recheck (see page 11-6). lf the symptom/indication
goes away with a known-good ECM, replace the
original ECM.I
NO Repair short to power in the wire between the
DLC terminal No.7 and the ECM (E23). After
repairing the wire, check the DTC with the OBD ll
scan tool/Honda PGM Tester, and go to the DTC
Troubleshooting index. I
t

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

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
1 21345611 | 1.,'I
1011112,/56,/r8119l2C21
2312428129130
L(BRN/YEL)
ALTF(WHT
213 4t561
89ltal,/l/15
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.