2003 HONDA CIVIC Start

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
ldle Speed lnspection
NOTE:' Leave the idle air control (lAC) valve connecled.. Before checking the idle speed, check these items:- The malfunction indicator lamp (MlL) has not been
reported on.- lgnition timing- Spark plugs- Air cleaner- PCV system. Pullthe parking brake lever up. Start the engine, and
make sure the headlights are off.
1. Disconnect the evaporative emission (EVAP)
canister purge valve 2P connector.
2. Connect a tachometer (A)to the test tachometer
connector (B), or connect the Honda PGM Tester (C)
or an OBD ll scan tool to the data link connector(DLC) (D) located under the driver's side of the
dashboard.
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4.
3.
5.
6.
Start the engine. Hold the engine at 3,000 rpm with
no load (in neutral) until the radiator fan comes on,
then let it idle.
Check the idle speed with no-load conditions;
headlights, blower fan, radiator fan, and air
conditioner off.
ldle speed should be: 750 t 50 rpm
Let the engine idle for 1 minute with the heater fan
switch on Hl and air conditioner on, then check the
idle speed.
ldle speed should be: 750 t 50 rpm
NOTE: lf the idle speed is not wilhin specification,
go to the Symptom Troubleshooting Index,
Reconnect the EVAP canister purge valve 2P
connector.

ECM ldle Learn Procedure
The idle learn procedure must be done so the ECM can
learn the engine idle characteristics.
Do the idle learn procedure whenever you do any of
these actions:. Disconnect the battery.
Replace the ECM or disconnect its connector.
Reset the ECM.
NOTE: Erasing DTCS with the Honda PGM Tester
does not require you to do the idle learn procedure.
Remove the No.6 ECU {ECM) ( 15A) fuse from the
under-hood fuse/relay box.
Remove the No.19 baftery (80A) fuse from the under-
hood fuse/relay box.
Remove PGM-FI main relay 1.
Remove any of the wires from the under-hood fuse/
retay Dox.
Disconnect any of the connectors from the under
hood fuse/relay box.
Disconnect the connector between the engine
compartment wire harness and ECM wire harness.
Disconnect the G2 terminal from the transmission
ho u srng.
Disconnectthe G'l terminal from the body.
Disconnectthe G101 terminal from the cylinder head
cover.
Procedure:
To complete the idle learn procedure, do this:
1. Make sure all electrical items (Ay'C, audio, rear
defogger, l:ghts, etc.,) are off.
2. Start the engine, and hold it at 3,000 rpm with no
load {in neutral) until the radiator fan comes on, or
until the engine coolanttemperature reaches 194"F(90'c).
3. Let the engine idle for about 5 minutes with the
throttle fully closed.
NOTE: lf the radiator fan comes on, do not include its
running time in the 5 minutes.
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FuelSupply System
Fuel Pressure Relieving
Before disconnecting fuel lines or hoses, relieve
pressure from the system by disconnecting the fuel
tube/quick connect fitting in the engine compartment.
1. Turn the ignition switch OFF,
2. Remove the PGM-Fl main relay 2 (A).
Startthe engine, and let it idle until it is stalls.
NOTE: The DTCS or Temporary DTCS P0301. P0302,
P0303, P0304 may come on during this procedure.
lf any DTCS are stored, ignore them.
Turn the ignition switch OFF.
Remove the fuel fill cap, and relieve fuel pressure
in the fueltank.
Remove the engine cover.
Disconnect the negative cable from the battery.
Check the fuel quick-connect fitting for dirt, and
clean it if necessary.
3.
4.
6.
7.
8.
11-144
11
10.
9. Place a rag or shop towel over the quick-connect
fitting (A).
Disconnect the quick-connect fifting (A): Hold the
connector (B) with one hand and squeeze the
retainer tabs (C) with the other hand to release
them from the locking pawls {D). Pullthe connector
off.
NOTE:. Prevent the remaining fuel in the fuel feedlineor
hose from flowing out with a rag or shop towel.. Be careful notto damage the line (E) or other
pa rts.. Do not use tools.. lf theconnectordoes not move, keepthe retainer
tabs pressed down, and alternately pull and push
the connector until it comes off easily.. Do not remove the retainer from the line; once
removed, the retainer must be replaced with a
new one.
After disconnecting the quick-connect fifting, check
it for dirt or damage (see page 1 1-149).

Fuel Pressure Test
Special Tools Required. Fuel pressure gauge 07406-0040004. Fuel pressure gauge sel 07ZAJ-S5A0100
1. Relieve the fuel pressure (see page 1'1-144).
2. Disconnect the quick-connect fitting (A). Aftach the
fuel pressure gauge set and fuel pressure gauge.
Start the engine and let it idle.
. lf the engine starts, goto step 5.. lf the engine does not start, goto step 4.
Check to see if the fuel pump is running: 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 pump runs, go to step 5.. lf the pump does not run, do the fuel pump circuit
troubleshooting (see page 1 1-1 41 ).
Read the pressure gauge. The pressure should be
320-370 kpa (3.3-3.8 kgf/cm', a7-52 psi)
. lf the pressure is OK, the test is complete.. lf the pressure is out of specification, replace the
fuel pressure regulator and the fuel filter (see
page 11-152), then recheck the fuel pressure.
5.
11-145

Intake Air System
Throttle Cable Removal/lnstallation
1. Fully open the throttle valve, then remove the
throttle cable (A) from the throttle link (B).
Remove the cable housing (C)from the cable
bracket (D).
Remove the throttle cable (A)from the accelerator
pedal (B).
2.
3.
SILICONE GREASE B(P/N 08798-9002)
(P/N 08?98-9002)
11-164
5.
Install in the reverse order of removal.
After installing, start the engine. Hold the engine at
3,000 rpm with no load (in neutral) untilthe radiator
fan comes on, then let it idle.
Hold the cable, removing all slack from it.
Set the locknut on the cable bracket {A).Turn the adjusting nut (B) so that its free play is
0 mm.
The should beno crearance.
Remove the cable from the cable bracket (A). Set
the adjusting nut on the other side of the throttle
bracket, then tighten the locknut {C}.
With the cable properly adjusted, check the throttle
valve to be sure it opens fully when you push the
accelerator pedal to the floor. Also check the
throttle valve to be sure it returns to the idle
position whenever you release the accelerator
Deoat.
7.
!
8.
9.
('1.0 kgf.m,7.2 tbf.ftl

Catalytic Converter System
DTC Troubleshooting
DTC P0420: Catalytic System Efficiency
Below Threshold
NOTE: lf some of the DTCS listed below are stored at
the same time as DTC P0420, troubleshoot those DTCS
first, then recheck for DTC P0420.
P0137, P0138: Secondary Heated Oxygen Sensor(secondary HO2S) (Sensor 2)
P0141: Secondary HO2S (Sensor 2) heater
1. Reset the ECM {see page 1'l-4}, then continue to
step 2 through 5 to reset the readiness code.
2. Start the engine. Hold the engine at 3,000 rpm with
no load (in neutral) untilthe radiator fan comes on.
Drive for about l0 minutes without stopping. Your
speeo can vary.
With the transmission in 4th gear, drive at a steady
speed between 50 62 mph (80-'100 km/h) for
30 seconds.
Repeat step 4 three times. Between each repetition,
close the throttle completely for 1 2 seconds. lf
the engine is stopped during this part of the
procedure, repeat steps 3, 4 and 5.
Check for a Temporary DTC with the scan tool.
Does the scan tool indicate Temporaty DTC
P0420?
YES Check the TWC. lf necessary, replace the
TWC.I
NO Check for readiness code completion. lfthe
readiness is complete, it was a interminent failure,
and the system is OK at this time. lf the readiness
code is incomplete, repeat steps 2 through 5.1
4.
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PCV System
DTC Troubleshooting
DTC P1505: PCV Air Leakage
1. Reset the ECM (see page 11-4).
2. Start the engine. Hold the engine at 3,000 rpm with
no load (in neutral) until the radiator fan comes on
3. Let the engine idle tor al least 40 seconds with the
throttle fully closed.
4. Check for a DTC P1505 with the scan tool
ls DTC P1505 indicated?
YES-Check these parts for vacuum leaks l
. PCV valve. PCV hose. EVAP canister purge valve
. Throttle body. Brake booster hose
NO - Intermittent failure, system is OK at this
time.l
11-168