2003 HONDA CIVIC hood open

PGM-FI System
aDTG Troubleshootang (cont'dl
DTC P0128: Cooling System Malfunction
NOTE; lf the DTCS listed below are stored at the same
time as DTC P0128. troubleshoot those DTCS first, thenrecheck for P0128.
P0107, P0108, P1128, P1129: N4anifold absolutepressure (MAP) sensor
P] I06, P1 107, P1 108: Barometric pressure (BARO)
sensor
P1259: VTEC system
P01 16, P01 17, P01 18: Engine coolant temperature (ECT)
sensor
P01 12, P01 13: Intake air temperature (lAT) sensor
P0500: Vehicle speed sensor {VSS)P0335, P0336: Crankshaft position (CKP) sensor
P0300: Random misfire
P0301, P0302, P0303, P0304: No. 1, No. 2, No.3 or No.4
cylinder misfire
P0505: ldle control system malfunction
P1519: ldle air control (lAC)valve
DTC P0128 can occasionally set when the hood is
opened while the engine is running.
1. Check the engine coolant level
Is the engine coolant level low?
VES Refill the engine coolant. lf necessary, repair
the coolant leakage.l
NO Go to step 2.
2. Turn the ignition switch ON (ll), and make sure the
A,/C is off.
11-64
\
3. Check the radiator fan.
Does the tadiator fan keep running?
YES Checkthe rad iato r fan circuit (see page 10-
14), the radiator fan switch circuit (Short) (see page
10-'16), and the radiator fan switch (see page 10-17).
Also, inspect the ECT and IAT circuits and terminal
connections. lf the circuits, the switch, and the
connections are OK, update the ECI\4 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 Replace the thermostat (see page 10-8).1

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)(

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

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

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 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

EPS Components
DTC Troubleshootang (cont'dl
DTC 62: EPS Control Unit Internal Circuit
(Fail-safe Relay Stuck ON)
'1. Clear the DTC.
2. Start the engine.
Does the EPS indicator come on?
YES-Go to step 3.
NO-Check for loose wires or poor connections. lf
the connections are good, the system is OK at this
time.I
3. Stop the engine, and verify the DTC.
ls DTC 62 indicated?
YES-Check for loose or poor connections at the
EPS control unit. lf the connections are good,
substitute a known-good EPS control unit. lf the
symptom/indication goes away, replace the
original EPS control unit and recheck.l
NO-Perform the appropriate troubleshooting for
the code indicated. t
17-44
DTC 64: Battery Voltage is Excessively Low
(Fail-safe Relay Contact Failure and Motor
Voltage FallOff)
1. Clear the DTC.
2. Start the engine.
Does the EPS indicatot come on?
YES Go to step 3.
NO Check for loose wires or poor connections. lf
the connections are good, the system is OK at this
trme.l
3. Stop the engine, and verify the DTC.
ls DTC 64 indicated?
YES Go to step 4.
NO Perform the appropriate troubleshooting for
the code indicated.
4. Check the No. '18 (604) fuse in the under-hood fuse/
relay box, and reinstallthe fuse if it is OK.
Is the f use OK?
YES Go to step 5.
NO Replace the fuse and recheck.l
5. Disconnect EPS control unit connector A (2P).
6. Measure the voltage between EPS control unit
connector A (2P) terminal No. 1 and body ground.
-Blwt{r/Bl.ur Hl
\9
I
ls there battety voltage?
YES - Check for loose or poor connections at the
EPS control unit connectors, and check for a poor
ground at G 15 1. lf necessary, substitute a known-
good EPS control unit and recheck.l
NO Repair open in the WHT/BLU wire between
the No. 18 (60,4)fuse and EPS control unit.l
(