2003 HONDA CIVIC FUEL AND EMISSION

Fuel and Emissions Systems
Rel. No.Tool NumberDescriptionotv(L)
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A973X-041-XXXXX
07JAZ-0010008
07sAz-001000A
07vAJ-0040100
07NAJ-P07010A
07xAA-001010A
07zAJ-S5AA200
07406-0020201
07406-0070300
OTMAJ-PY4O11A
07MAJ-PY40120
07406-004000A
07zAJ-S5A0100
Vacuum Pump/Gauge, 0 30 in.Hg
Vacuum/Pressure Gauge. 0 4 in.Hg
Backprobe Set
Fuel Pressure Gauge Adapter
Pressure Gauge Adapter
Fuel Sender Wrench
Hose, Oil Pressure
A,/T Pressure Hose
A,/T Low Pressure Gauge W/Panel
A,/T Pressure Hose ,2,210 mm
A,/T Pressure Hose Adapter
Fuel Pressure Gauge
Fuel Pressure Gauoe Set
1
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2
1
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11-2
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Fuel and Emissions Systems
General Troubleshooting Information (cont'dl
How to Reset the ECM
You can reset the ECM in either of two ways:
. Use the OBD ll scantool or Honda PGMTesterto
reset the ECM memory.
See the OBD ll scan tool or Honda PGI\4 Tester user's
manuals for specific instructions.' Turn the ignition switch OFF, and remove the No. 6
ECU {ECM} (15A) fuse (A)from the under-hood fuse/
relav box (Blfor 10 seconds.
How to End a Troubleshooting Session
(required after any troubleshootingl
1. Reset the ECM as described above.
2. Do the ECM idle learn procedure (see page 11-139)
3. Turn the ignition switch OFF.
4. Disconnectthe OBD ll scan tool or Honda PGM
Tester from the DLC.
NOTE: The ECM is part of the immobilizer system.
lf vou replace the ECM, it will have a different
immobilizer code. In order for the engine to start,
you must rewrite the immobilizer code with the
Honda PGM Tester.
11-4
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How to Remove the ECM for Testing
1. Remove the passenger's dashboard lower cover
{see page 20-63), the passenger's kick panel (see
page 20-63), and the glove box (see page 20-63).
2. Remove the ECM mounting bolts (B) and the ECM
(c),
9.8 N.m{1.0 kgf.m,7.2lbt.ft}
3. Remove the ECM (B).
4. Installthe ECM in the reverse order of removal.
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Fuel and Emissions Systems
General Troubleshooting Information (cont'd)
ECM Updating and Substitution for Testing
Special Tools Bequired
Honda Interface Module (HlM) EOS05435570
Use this procedure when you have to substitute a
known-good ECM in a troubleshooting procedure.
U pdate the ECM only if the ECN4 does not already have
the latest software loaded,
NOTE;. lMake sure the battery is fully charged before you
update the ECN4.. To prevent ECM damage during the update, do not
turn the ignition switch OFF, and do not use any of
the vehicle's electrical devices (light, horn, radio, etc. ).
How to Update the ECM
1. Turn the ignition switch ON (ll). Do not startthe
eng Ine.
2. Connect the Honda lnterface Module (HlM) to the
Data Link Connector {DLC) (A) located under the
driver's side of dashboard.
EOS05A35570
Do the ECM update procedure as described on the
HlN4 label and in the ECM update system.
11-6
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How to Substitute the ECM
'1. Remove the ECM f rom the vehicle.
2. Install a known-good ECM in the vehicle.
3. Rewrite the immobilizer code with the ECM
replacement procedure from the Honda PGM
Tester. lt allows you to start the engine.
4. After completing your tests, reinstall the original
ECM and rewrite the immobilizer code with the
ECM replacement procedure on the Honda PGM
Tester again.
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Fuel and Emissions Systems
Knock Sensor Circuit N4alfunction
Crankshaft Position (CKP) Sensor Intermittent(see page 11-78)
(see oaqe 11-121
PO4i{
TU45I
P0452
Camshaft Position (CMP) Sensor A Intermiftentisee page 11-121)
Yetrgb-le Velye TiTing _controlll/T!) Phqse Gsee oaoe 11-122
CqJalyst System Elficie-ncy Below Thresholdsee oaqe 1 1- 167
Fuel Tank Pressure (FTP) Sensor Range/Performance (seepagell 171)
Sensor Circuit Low V11-172
Fuel Tank Pressure (FTP) Sensor Circuit High V
Vehicle SDeed SensorCircuit Malf unction
Camshaft Position (CMP) Sensor A No
P0451 (91)
see Daqe 11-130)
(see page 1 1-81)
Refer to the l\4ultiplex
Control System
Troubleshooting {see
(see page 1 1-83)
(see paSe 1 1'83)
Barometric Pressure (BARO) Sensor Circuit High{see page 11-83)
P't 121
Pl122
P11f,.8
Throttle Position {TPi Sensor Signal Lower Than(see page 11-63)
-tsee page I r-oJ,
G;tp"s" 1 154)
(*" paSe 1 154)
P1122 ll J
ij1128 (5)
Throttle Position (TP) Sensor Signal Higher Than
Mani{old Absolute Pressure (l\,4AP} Sensor Signal
Loqer Tha n Expected
Manifold Absolute Preisure (MAP) SeiiioiSgnul
Hiqher Than Ex(see page 11-84)
Engine Control Module (ECN4) Power Source Circuil
Serial Communication Link Malfunction
P1106 (13)
P110? (13
P1 108 (ts'
Barometric Pressure (BARO) Sensor Range/
Performance Problem
Barometric Pressure (BARO) Sensor Circuit Low
P1121 11)
P1 129 (5)
P1157 (48)
Pr 158 (48)
Air Fuel Ratio (AVF) Sensor (Sensor 1) Range/
Rerformance Problem
AirFuel Ratio{A"F) Sensor {Sensor 1)AFS Terminal(see page 1 1-85)
Air Fuel Ratio 1AVF) Sensor isensor 'l) AFS + Terminal(see page 1 1-86)
Air Fuel Ratio {A,/F) Sensor {Sensor I ) Slow Response
Air Fuel Ratio (A/F) Sensor (Sensor 1) Range/(see page 1 1-88)
Air Fuel Ratio (4,/F) Sensor (Sensor 1) Heater Circuit
Malfunction
(see page 11-89)
Air Fuel Ratio (A,/F) Sensor (Sensor 1) Heater System
Malfunction
(see page 11-91)
P1 159 (48)
P1163 (61
P1164 (61)
P1 166 (41)
P1 167 (41) '
DTC Troubleshooting Index (cont'd)
" :These DTCS are indicated by a blinking MIL when the SCS servlce signal line is jumped with the Honda PGM
Tester.* 1r '02 model
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11-8
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Fuel and Emissions Systems
Symptom Troubleshooting Index
When the vehicle has one of these symptoms, check the diagnostic trouble code (DTC) with the scan tool. lf there is no
DTC, do the diagnostic procedure for the symptom, in the sequence listed, until you find the cause.
SvmotomDiaqnostic procedureAlso check lor
Engine will not sta rt
(MlL works OK, no DTCS set)
1. Test the battery {see page 22-50).
2. Test the starter (see page 4-8).
3. Troubleshoot the fuel pump circult (see page 11
141).
Low compressron
No ignition spark
lntake air leaks
Locked up engine
Broken timing chain
Contaminated fuel
Engine will not start (MlL
comes on and stays on, or
never comes on at all, no
DTCS set)
Troubleshoot the l\4lL circuit (see page 1 '1-97).
Engine will not start
(immobilizer indicator stays
on or flashs)
Troubleshoot the immobilizer system (see page 22-165).
Hard starting(MlL works OK, no DTCS set)
1. Testthe battery (see page 22-50).
2. Checkthe fuel pressure (see page 11-145).
Low compression
Intake air leaks
Contaminated fuel
Cold fast idle too low(MlL works OK. no DTCS set)
1. Do the ECM idle learn procedure (see page 11-139).
2. Checkthe idle sDeed (see paqe 11-138).
Cold fast idle too high
(MlL works OK, no DTCS set)
Do the ECI\4 idle learn procedure (see page 1 1- 139).
Checkthe idle speed {see page 11-138).
Inspect/adjust the throttle cable (see page 1 '1-'163).
Inspect and test the throttle body {see page 1 1-160}.
']
2.
3.
ldle speed fluctuates
(MlL works OK, no DTCS set)
1. Dothe ECM idle learn procedure (see page 11-'139).
2. Check the idle speed (see page 11-138).
3, Inspecvadjust th e throttle cable (see page 11''163).
4. Insoect and test the throttle bodv (see paqe 11- 160)
Intake air leaks
After warming up, idle speed
is below specifications with
no load
{MlL works OK, no DTCS set)
1. Do the ECIVI idle learn procedure (see page 1 1- 139).
2. Troubleshootthe alternator FR signal circuit (see
page 11-'134).
3. InsDect and test the throttle bodv {see paqe 1 1-160).
Vacuum hose clogged/
cracked/poor
connectron
After warming up, idle speed
is above specifications with
no toao(MlL works OK. no DTCS set)
1. Do the ECM idle learn procedure {see page 1'j-139).
2. Troubleshoot the alternator FR signal circuit(see
page 11-134).
Low power
(MlL works OK, no DTCS set)
1. Check the fuel pressure(seepagell-145).
2. Inspect and test the th roftle body (see page 11-160).
3. Inspecvadjust the throttle cable (see page 11-'163).
Low compressron
Camshaft timing
problem
Engine oil levelprootem
Engine stalls(MlL works OK. no DTCS set)
1. Do the ECM idle learn procedure (see page 1'l'139).
2. Check the fuel pressure{seepagell-145).
3. Check the idle speed (see page I 1-138).
4. Troubleshootthe brake pedal position switch signal
circuit (see paqe 11-137).
lntake air leaks
Faulty harness and
sensor connections
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11-10
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Fuel and Emissions Systems
System Descriptions
Electronic Control System
The functions of the fuel and emlssion control systems are managed by the engine control module (ECM).
Fail-safe Function
When an abnormality occurs in the signal from a sensor, the ECI\4 ignores that signal and assumes a pre-programmed
value for that sensor that allows the enqine to continue to run.
Back-up Function
When an abnormality occurs in the ECM, the injectors are controlled by a back-up circuit independent of the system to
permit minimal driving.
Self-diagnosis
When an abnormality occurs in the signal from a sensor, the ECM supplies ground for the malfunction indicator lamp
{MlL) and stores the diagnostic trouble code {DTC) in erasable memory. When the ignition is first turned on, the EClvl
supplies ground to the l\4lL for 15 to 20 seconds to check the M lL bulb condition.
Two Driving Cycle Detection Method
To prevent false indications, the "two driving cycle detection method" is used for some self-diagnostic functions.
When an abnormality occurs, the ECM stores it in its memory. When the same abnormality recurs afterthe ignition
switch is turned OFF and ON (ll) again, the ECM turns on the MlL.
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11-12
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Fuel and Emissions Systems
System Descriptions (cont'd)
ECM Data (cont'd)
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DataDescriptionOpera'ting ValueFreeze Data
Fuel System
Status
Fuel system status is indicated as "open" or "closed".
Closed: Based on the A,/F Sensor output, the ECM
determines the airlfuel ratio and controls the amount of
injected fuel.
Open: lgnoring Ay'F Sensor output, the ECM refers to
signals from the throttle position {TP), manifold absolute
pressure (MAP), intake air temperature (lAT), barometric
pressure (BARO), and engine coolant temperature (ECT))
sensors to control the amount of iniected fuel.
At idle speed: closedYES
Short Term
FuelTrim
The airlfuel ratio correction coefficient for correcting the
amount of injected fuel when the fuel system status
is "closed." When the ratio is leaner than the
sloichiometric ratio, the ECM increases short term fuel
trim gradually, and the amount of iniected fuel increases.
The airlfuel ratio gradually gets richer, causing a lower
oxygen content in the exhaust gas. Consequently, the
short term fuel trim is lowered, and the ECM reduces the
amount of injected fuel.
This cvcle keeps the airlfuel ratio close to the
stoichiometric ratio when in closed loop status.
o.7 1.5YES
Long Term
Fuel Trim
Long term fuel trim is computed from short term fuel trim
and indicates changes occurring in the fuel supply system
over a long period.
lf long term fuel trlm is higher than 1.00, the amounl of
injected fuel must be increased. lf it is lower than 1.00, the
amount of injected fuel must be reduced.
0.8 1.2YES
Intake Air
Temperature
{IAT)
The IAT sensor converts intake air temperature into
voltage and signals the ECM. When intake air
temperature is low, the internal resistance ofthe sensor
increases, and the voltage signal is higher.
With cold engine:
Same as ambient
temperature and ECT
YES
Throttle
Position
Based on the accelerator pedal position, the opening
anole of the throttle valve is indicated.
At idle speed:
about 10 %
YES
lgnition
Timing
lgnition timing is the ignition advance angle set by the
ECM. The ECM matches ignition timing to driving
conditions.
At idle speed: 8" t 5"
|' tuL wnen rne >L)
service signal line is
jumped with the Honda
PGM Tester
NO
Calculated
Load Value
(cLV)
cLV is the enoine load calculated from IMAP data.At idle speed:
12 34%
At 2.500 rpm with no
toao:'t4- 34%
YES
11-14
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Fuel and Emissions Systems
aSystem Descriptions (cont'dl
ECM Electrical Connections
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No. INJECTOR
No,2INJECTOR
No.3 INJEC]OB
No./tINJECTOF
MAPSENSON
TPSENSOR
IATSENSOR
ECTSENSOB
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CMP SENSOR B(TDC SENSOSJ
CKPSENSOR
11-16
F€VERSE LOCKSOLENOIDVAIVE
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