ecm HONDA CIVIC 2003 7.G Manual Online

MIL Circuit Troubleshooting
1. Connect an OBD ll scan tool/Honda PGM Tester
(see page 11-3).
2. Turn the ignition switch ON (ll) and read the OBD ll
scan tool/Honda PGM Tester.
Does the OBD ll scan tool/Honda PGM Tester
communicate with the ECM?
YES Go to step 3.
NO Go to troubleshooting " DLC Circuit
Troubleshooting" (see page 11-109).
3. Check the OBD ll scan tool/Honda PGM Testerfor
DTCs.
Are any DTCs ind icated?
YES Go to the DTC Troubleshooting Index.
NO-Go to step 4.
4. Turn the ignition switch OFF.
5. Turn the ignition switch ON (ll)and watch the
lMalfunction Indicator Lamp (MlL).
Does the MIL come on and stay on for more than
20 seconds aftet turning the ignition switch
oN (tr)?
YES lf the MIL always comes on and stays on, go
to step 76. But if the lMlL sometimes works
normally, first check for these problems.
. An intermittent short in the wire between the
ECIM (E29) and the data link connector (DLC).
. An intermittent short in the wire between the
ECM (E31) and the gauge assembly.
NO lf the MIL is always off, go to step 6. But if the
lvllL sometimes works normally, first check for
these problems.
. A loose No. 10 METER (7.5A) fuse in the under
dash fuse/relay box.. A loose No. 20 lG (40A) (Canada: 50A)Iuse in the
under-hood fuse/relay box.. A ioose No. 6 ECU (ECM) (15A) fuse in the under-
hood fuse/relay box.
. A loose No. 17 FUEL PUMP (15A)fuse in the
under-dash fuse/relay box.. A poor connection at ECM terminal E31.. An intermittent open in the GRN/ORN wire
between the ECM (E31) and the gauge assembly.. An intermittent short in the wire between the
ECM (A21) and the manifold absolute pressure
(MAP) sensor.. An intermittent short in the wire between the
ECI\4 (A20) and the throttle posilion (TPi sensor.. An intermittent short in the wire between the
ECM (E5) and the fuel tank pressure (FTP) sensor.
6. Turn the ignition switch OFF.
7. Turn the ignition switch ON (ll).
ls the low oil pressure light on?
YES Go to step 10.
NO-Go to step 8.
8. Inspectthe No. 10 l\4ETER (7.5A)fuse inthe under-
dash fuse/relay box.
ls the luse OK?
YES Go to step L
NO Repair shon in the wire between No. 10
METER (7.5A)fuse and the gauge assembly. Also
replacethe No. 10 METER {7.5A) fuse.l
9. Inspect the No. 20 lG1 (40A) (Canada: 50A) fuse in
the under-hood fuse/relay box.
ls the f use OK?
YES Repair open in the wire between the No. 20
lG (40A) {Canadar 50A)fuse and the gauge
assembly. lf the wire is OK, test the ignition switch
{see page 22 53).
NO Repair short in the wire between No. 20 lG
(40A) lCanada: 50A)fuse and the under'dash fusel
relay box. Also replace the No.20 lG (40Ai
(Canada: 50A) fuse.I
(conr'd)
11-97

PGM-FI System
MIL Circuit Troubleshooting (cont'dl
11.
Try to start the engine.
Does the engine start?
YES-Go to step 11.
NO-Go to step 14.
Turn the ignition switch OFF.
Connect ECM connector terminal E31 to bodyground with a jumper wire.
10.
12.
ECM CONNECTOR E 13lPI
MIL(GRN/ORN}
Wire side of female terminals
Turn the ignition switch ON (ll).
ls the M lL on?
YES 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 ECIM, replace the
original ECM.I
NO-Check for an open in the wire between the
ECM (E31) and the gauge assembly. Also check for
a blown MIL bulb. lf the wires and the bulb are OK,
replace the gauge assembly.l
Turn the ignltion switch OFF,
Inspect the No. 6 ECU (ECIM) (15A) fuse in the
under-hood fuse/relay box.
ls the f use OK?
YES-Go to step 22.
NO-Go to step 16.
't 4.
15.
ll2l345617l 18I
415161,/ 1182(2t2'23 24z7l/ 12931
JUMPERWIRE
11-98
to.Remove the blown No. 6 ECU {ECfU) (154) fuse
from the under-hood fuse/relay box.
Remove the glove box (see page 20-63) and the
PGM'FI main relay 1.
Check for continuity between body ground and
PGM-Fl main relay 1 4P connector terminals No. 2
and No. 4 individuallv.
PGM-FI MAIN RELAY 14P CONNECTOR
Wrre srde ol lemale termrnals
ls there continuity?
YES-Repair short in the wire between the No.6
ECU (ECl\4) (15A) fuse and the PGM-Fl main relay 1.
Also replace the No.6 ECU (ECM) (15A) fuse.l
NO-Go to step 19.
17.
18.
fVBv) (wHr/
IA BLK)(

19. Disconnect each of the components or the
connectors below, one at a time, and check for
continuity between PGM-FI main relay 1 4P
connector terminal No. 1 and body ground.
. PGfvl-Fl main relay 2. ECM connector A (31P)
. Each injector 2P connector. ldle air control (lAC)valve 3P connector. Camshaft Position (CMP) sensor B (Top dead
center (TDC) sensor) 3P connector. Crankshaft position (CKP) sensor 3P connector
PGM-FI MAIN RELAY 14P CONNECTOR
ls thete continuity?
YES Go to step 20.
NO- Replace the component that made continuity
to body ground go away when disconnected. lf the
item is the ECM, 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.
Also replace the No. 6 ECU (ECM) (15 A) fuse,
Disconnect the connectors of all these components.
. PGM-Fl main relay 2. ECM connector A (31P)
. lnjectors. ldle air control (lAC)valve
. Camshaft Position {CMP) sensor B (Top dead
center (TDC) sensor). Crankshaft position (CKP) sensor
20.
Wire side of female terminals
22.
21. Check for continuity between PGM-FI main relay 1
4P connector termlnal No. 1 and body ground.
PGM-FI MAIN RELAY 14P CONNECTOR
ls there continuity?
YES Repair short in the wire between the PGM-Fl
main relay 1 and each item. Also replace the No. 6
ECU {ECM) (15A) fuse.l
NO-Replace the PGM-Fl main relay 1. Also replace
the No 6 ECU {ECIM) (15A) f use. I
Inspectthe No. 17 FUEL PUI\4P (15A)fuse in the
under-dash f use/relay box.
ls the tuse OK?
YES Go to step 34.
NO Go to step 23.
Remove the blown No, 17 FU EL PUMP (15A) fuse
from the under-dash fuse/relay box.
Disconnect ECfvl connector E (31P).
(conr'd)
23.
24.
Wire side of female terminals
11-99

PGM-FI System
25.
MIL Circuit Troubleshooting (cont'dl
Check for continuity between ECM connector
terminal E9 and body ground.
ECM CONNECTOR E (31P)
Wire side o{ {emale terminals
ls therc continuity?
YES-Go to step 26.
NO Replace the No. lTFUELPUMP(15A)fuse,
and 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
26. Remove the PGM-Fl main relay 2 (A).
11-100
27. Check for continuity between ECIVI connector
terminal Eg and body ground.
ECM CONNECTOR E 131P)
Wire side oI Jemale terminals
ls there continuity?
YES Repair short in the wire between the No. 17
FU EL PUMP (15A)fuse and the ECM (E9), or
between the No. 17 FUEL PU MP (15 A) fuse and the
PGM-FI main relay 2. Also replace the No. 17 FUEL
PUMP (15A)fuse.l
NO Go to step 28.
Remove the rear seat cushion (see page 20-80).
Remove the access panel from the floor.
Disconnect the fuel pump 5P connector.
\
28.
29.
30.

31. Check for continuity between fuel pump 5P
connector terminal No. 5 and body ground.
FUEL PUMP 5P CONNECTOR
Wire side of temale terminals
ls therc continuity?
YES Repair short in the wire between the fuel
pump and the PGM-Fl main relay 2. Also replace
thE NO. 17 FUEL PUMP (15A) fUSE.T
NO-Go to step 32.
32. Reinstallthe PGM-Fl main relay 2 (A).
33. Check for continuity between fuel pump5P
connector terminal No. 5 and body ground.
FUEL PUMP 5P CONNECTOR
=
Wire side ol lemal€ rerminals
ls there continuity?
YES Replace the PGM-Fl main relay 2. Also
replace the No. 17 FUEL PUMP (15A) fuse.l
NO Check the iuel pump, and replace il if
necessary. Also replace the No. 17 FUEL PUMP(15A) fuse.!
34. Disconnect ECM connector E (31P).
35. Turn the ignition swirch ON {111.
36. Measure voltage between ECM connectorterminal
E9 and body ground.
ECfl CON|{CCIOR E (3rPt
Wire side ol female lerminals
ls there battery voltage?
YES Go to step 37.
NO Repair open in the wire between the No. 17
FUEL PUMP (15A)fuse and the ECM (E9).1
(cont'd)
11-101

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

42.
43.
44.
45.
46.
Reconnect ECI\4 connector E {31P).
Turn the ignition switch ON (ll).
Measure voltage between body ground and ECM
connector terminals 42 and 43 individually.
Wire side of female terminals
ls there battery voltage?
YES Go to step 51.
NO Go to step 45.
Turn the ignition switch OFF.
Remove the PGM'Fl main relay 1{A)
,A
47. Turn the ignition switch ON (ll).
ECM CONNECTOR A {31PI
49.
50.
48. Measure voltage between PGM-FI main relay 1 4P
connector terminal No. 2 and body ground.
PGM.FI MAIN RELAY 14P CONNECTOR
ls there battery voltage?
YES Go to step 49.
NO Repair open in the wire between the No.6
ECU {ECM) (15A}fuse and the PGM-Fl main
relay 1 . !
Turn the ignition switch OFF.
Check for continuity between PGM-Fl main relay 1
4P connector terminal No. 1 and ECM connector
terminals 42 and 43 individually.
PGM.FI MAIN RELAY IilP CONNECTOR
ls there continuity?
YES Replace the PGM-Fl main relay 1.1
NO Repair open in the wire between the PGM-FI
main relay '1 and the ECM (A2, A3).1
{cont'd}
Wire side of temale terminals
IGPl (YEL/BLK)
Wire side of female terminals
11-103

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.

59. Check for continuitv between ECIM connector
terminal 421 and body ground.
ECM CONNECTOR A {3,IPI
Wire side of female terminals
ls there continuity?
YES*Repair short in the wire between the ECM(421) and the MAP sensor.l
NO Update the ECM it it does not have the latest
soflware, or substitute a known-good ECM, then
recheck (see page 1'l-6). lf the symptom/indication
goes away with a known-good ECM, replace the
original ECM.I
Measure voltage between body ground and ECM
connector terminal 420.
ECM CONNECTOR A {3TP}
60.
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101111256/ 11892t212'231?4?qTln29
vcc2IYEL/BLU)
Wire side ot female terminals
ls there about 5 V?
YES-Go to step 68.
NO-Go to step 61.
t t,
oz,
63.
64.
Turn the ignition switch OFF.
Disconnect the throttle position (TP) sensor 3P
connector.
Turn the ignition switch ON (ll).
Measure voltage between body ground and ECM
connector terminal 420,
ECM CONNECTOR A 131P)
Wire side of female terminals
ls there about 5 V?
YES Replace the thronle body (the TP sensor is
not available separately). I
NO Go to step 65.
Turn the ignition switch oFF.
Disconnect ECM connector A (31P).
65.
66.
conl o
11-105

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