2002 HONDA CIVIC ECU

J/-\-1\_/
BEIAY2
A/C CLUTCH RELAY
RAOIATOR
I
)
T
UNDER.HOODFUSE/RELAY BOX:ONo. 19 BATTERY (8oA)ONo. 6 ECU (ECM) (15A1(3)No.20lG {40A1{Canada:50A}ONo. l4 OPTION {40A1€)No. 9 BACK uP (7.5A1lo)No. 7 HORN, STOP {15A}
UNDER.DASHFUSE/RELAY BOX:ONo. 17 FUEL PUMP{15A}@No. ,t ACG {10A)ONo. 1 IGN COIL (1sA)q)No. 10 METER (7.5A)0)No. 14 A/C CLUTCHRELAY IlOA)@No.2 +B LAF (A/F)HEATER (2OA)
(cont'd)
11-15

DTC P0300: Random Misfire and Any Combination of the Following:
DTC P0301: No. 1 Cylinder Misfire
DTC P0302: No. 2 Cvlinder Misfire
DTC P0303: No, 3 Cvlinder Misfire
DTC P0304: No. 4 Cvlinder Misfire
NOTE:. lfthe misfiring is frequent enough to trigger detection of increased emissions during two consecutive driving cycles.
the MIL will come on, and DTC P0300 (and some comlrination of P0301 through P0304) will be stored.. lf the misfiring is frequent enough to damage the catalyst, the MIL will blink whenever the misfiring occurs, and OTC
P0300 (and some combination of P0301 through P0304) will be stored. When the misfirlng stops, the MIL will remain
on.
1. Troubleshoot the following DTCs first if any of them were stored along with the random misfire DTC(s):
P0'107, P0108, P1128, P1129r N4anifold absolute pressure (MAP) sensor
P0111. P0'172t Fuel svstem
P0335. P0336: Crankshaft position (CKP) sensor
P0505: ldle control system
P1 149, Pl 162, P1 163, P1 164, P 1 165: Air fuel ratio (Ay'F) sensor
P1259: VTEC system
P1361, P1362: Camshaft position (CMP) sensor B {Top dead center (TDC) sensor)
P1519: ldle air control (lAC) valve
2. Test-drive the vehicle to verify the symptom.
3. Findthesymptom inthechart below, and dothe related procedures in the order listed until you find the cause.
SymptomProcedure(slAlso check foi:
Random misfire only
at low RPM and
under load
Check fuel pressure (see page 1 1-145).. Low compressron.. Low quality fuel.
Random misfire only
du ring acceleration
Check fuel pressure (see page 11-145).Malfunction in the
VTEC system (see page
1't-123).
Random misfire at
high RPM, under
load, or under
random conditions
Check fuel pressure (see page 11-145).Correct engine valve
clearances (see page 6-
91.
11-71

PGM-FI System
IDTC Troubleshooting (cont'dl
DTC P0301: No. 1 Cylinder Misfire
DTC P0302: No. 2 Cylinder Misfire
DTC P0303: No. 3 Cylinder Misfire
DTC P0304: No. 4 Cylinder Misfire
1. After checking and recording the freeze data, reset
the ECM (see page 1 1-4). lf there is no freeze data of
the misfire, just clear the DTC.
2. Start the engine, and listen for a clicking sound
from the injector at the problem cylinder.
Does the injector click?
YES-Go to step 3.
NO-Go to step 30.
3. Turn the ignition switch OFF.
4. Exchange the ignition coil from the problem
cylinder with one from another cylinder,
5. Test-drive the vehicle for several minutes in the
range of the freeze data or under va rious
conditions if there was no freeze data.
6. Check for a DTC or a Temporary DTC with the scan
root.
ls DTC or Tempotaty DTC P0301, P0302, P0303
or P0304 ind icated?
YES Go to step 7.
NO Intermittent misfire due to poor contact at the
ignition coil connectors {no misfire at this time).
Make sure the coil connections are secure.l
11-72
8.
9.
1.
11.
Determine which cylinder(s) had the misfire.
Does the misf ire occur in the cylinder where the
ignition coil was exchanged?
YES Replace the faulty ignition coil.!
NO-Go to step 8.
Turn the ignition switch OFF.
Exchange the spark plug from the problem cylinder
with one from another cylinder.
Test-drive the vehicle for several minutes in the
range of the freeze data or under various
conditions if there was no freeze data.
Check for a DTC or Temporary DTC with the scan
Tool.
ls DTC ot Tempotary DTC P0301, P0302, P0303
or P0304 ind icated?
YES Go to step 12.
NO Intermittent misfire due to spark plug fouling,
etc. (no misfire at this time).1
Determine which cylinder(s) had the misfire.
Does the misl ire occur in the cylinder where the
spark plug was exchanged?
YES Replace the faulty spark plug.l
NO Go to step 13.
Turn the ignition switch OFF.
Exchange the lnjector from the problem cylinder
with one from another cylinder.
Let the engine idle for 2 minutes.
10.
14.
t5.

16.Test-drive the vehicle for several minutes in the
range of the freeze data or under various
conditions if there was no freeze data.
Check for a DTC or a Temporary DTC with the scan
Tool.
ls DTC or Temporary DTC P0301, P0302, P0303
or P0304 indicated?
YES Go to step 18.
NO lntermittent misfire due to bad contact at the
injector connector (no misfire at this time). Make
sure the injector connection is secure. Check for
poor connections or loose terminals at the
injector.l
Determine which cylinder(s) had the misfire.
Does the misf ire occur in the cylinder where the
i njector w as exchanged ?
YES- Replace the faulty injector.I
NO-Go to step 19.
Turn the ignition switch OFF.
Disconnect the ignition coil 3P connector from the
problem cylinder.
Turn the ignition switch ON (ll).
't7 .
18.
19.
20.
22. Measure voltage between ignition coil 3P
connector terminal No. 3 and body ground.
IGNITION COIL 3P CONNECTOR
Wire side ol female terminals
ls there battery voltage?
YES-Go to step 23.
NO Repair open in the wire between the No. 1
IGN COIL (15A)fuse and the ignition coil.I
Turn the ignition switch OFF.
Check for continuity between ignition coil 3P
connector terminal No. 2 and body ground.
IGNITION COIL 3P CONNECTOR
Wire side ot female terminals
ls there continuity?
YES Go to step 25.
NO Repair open in the wire between the ignition
coiland G101.1
Disconnect ECM connector A {31P)
23.
24.
(cont'd)
11-73

32. fvleasure voltage between body ground and ECM
connector terminal (see table).
ECM CONNECTOR B (24P)
Wire side of female termrnals
ls there battery voltage?
YES-Go to step 33,
NO Go to step 41.
Turn the ignition switch OFF, and remove the
engine cover.
Disconnect the injector 2P connector from theproblem cylinder.
Measure the resistance between injector 2P
connector terminals No. 1 and No. 2.
INJECTOB 2P CONNECTOR
Terminal side of male terminals
ls there 10 Q 13A?
YES-Go to step 36.
NO Replace the injector (see page 1 1- 11 I ). t
33.
34.
35,
PROBLEM
CYLINDER
DTCEC t\4
TERMINAL
WIRE
COLOR
No. 1P0301B5BRN
No.2P0302B4RED
No.3P0303B3BLU
No.4P0304YEL
36.Exchange the injector from the problem cylinder
with one from another cylinder.
Letthe engine idle for 2 minutes.
Test-drive the vehicle for several minutes in the
range oI the lreeze data or under various
condilions if there was no freeze data.
Check for a DTC or Temporary DTC with the scan
tool.
ls DTC or Temporary DTC P0301, P0302, P0303,
or P0304 indicated?
YES Go to step 40.
NO Intermittent misfire due to injector
malfunction, etc. Make sure the injector
connections are secure. Check for poor connections
or loose terminals at the injector connector.l
Determine which cylinder{s} had the misfire.
Does the mislirc occur in the cylinder whete the
i nj ector w as exchanged ?
YES Replace the faulty injector.l
NO Update the ECM if it does not have the latest
software, or substitute a known-good ECM. then
recheck (see page 1 'l-6). lf the symptom/indication
goes away with a known-good EClvl, replace the
original ECM.I
Turn the ignition switch OFF.
Remove the engine cover.
Disconnect the injector 2P connector from the
problem cylinder.
44. Turn the ignition switch ON (ll)
37.
38.
39.
41.
42.
43.
(cont'd)
11-75

PGM-Fl System
6.
1.
DTC Troubleshooting (cont'dl
DTC P0500: VSS Circuit Malfunction
1. Test-drive the vehicle.
2. Check the vehicle speed with the scan tool.
ls the correct speed indicated?
YES-lntermiftent failure, system is OK at this time.
Check for poor connections or loose terminals at
the VSS and at the ECM.I
NO Go to step 3.
3. Turn the ignition switch OFF.
4. Block the rear wheels, and set the parking brake.
5. Raise the front ofthe vehicle, and make sure it is
securely supported,
Turn the ignition switch ON (ll).
Block the right front wheel, and slowly rotate the
left front wheel.
8. Measure voltage between ECM connector
terminals A18 and A24.
ECM CONNECTOR A {31P)
Wire side of female terminals
Does the voltage pulse between 0 V and 5 V or
between 0V and battery voltage?
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 ECM, replace the
original ECN4.l
NO Go to step 9.
11-80
9. Turn the ignition switch OFF.
10. Disconnect ECM connector A (3'1P).
1 1. Turn the ignition switch ON {ll}.
12. Blockthe right front wheel. and slowly rotate the
left front wheel.
'!3. lMeasure voltage between ECM connector
terminals A18 and A24.
ECM CONNECTOR A I31PI
Wire side of female terminals
Does the voltage pulse between 0 V and 5 V ol
between 0V and battety voltage?
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 ECM, replace the
origlnal ECM.I
NO Check these items:
. A short or an open in the wire between the ECM
(A18) and the VSS.I. lf thewire is OK,testtheVSS (see page 22 71).1

DTC P0563: ECM Power Source Circuit
U nexpected Voltage
1. Reset the ECI\4 {see page l1-4}.
2. Turn the ignition switch OFF.
3. Wait 5 seconds.
4. Turn the ignition switch ON {lll.
ls DTC P0563 indicated?
YES Go to step 5.
NO-lntermiltent failure, system is OK at this time.
Check for poor connections or loose terminals at
the No. 6 ECU (ECM) {15 A) fuse in the under-hood
fuse/relay box and at the ECM.I
Turn the ignition switch OFF.
Disconnect ECI\4 connector E {31P).
Turn the ignition switch ON (ll).
lvleasure voltage between ECM connector terminal
E7 and body ground.
6.
7.
8.
ECM CONNECTOR E {31P}
Wire side ol remale terminals
ls there battery voltage?
YES Go to step 12.
NO Go to step 9.
MRLY
9.
10.
Remove the glove box (see page 20-63).
Remove the PGM-FI main relay 1 (A7.
Check for continuity between ECM connector
terminal E7 and body ground.
ECM CONNECTOR E 131P)
MRLY{RED/YEL)
Wire side of {emale terminals
ls there continuity?
YES-Repair short in the wire between the ECM
{E7) and the PGM-Fl main relay 1 ,I
NO Replace the PGM-Fl main relay 1.1
Turn the ignition suitch OFF.
Reconnect ECM connector E (31P).
11.
tt.
'13.
(conl'd)
11-81

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