2002 HONDA CIVIC ignition

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
\.
\{

Fuel and Emissions Systems
System Descriptions (cont'd)
ECM Data (cont'd)
w
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
\.,
ra

EVAPCANISTE6PURGE VAIVE
EVAPCANISTERVENTSHUTVATVE
sotENotovAtvE
A/FSENSOR
A/FSENSOR(sENSOn 1)
CMP SENSOF A
VIC OIL CONTROLSO!ENOIDVALVE
wEcorlPRESSUSE SWTICH
VTEC SOLENOID
{cont'd)
11-17
No. 1 IGNITION COIL
No.2lGNlllON COIL
No. 3 IGNITION COIL
No. a IGNITION COIL

ECM Inputs and Outputs at Connector A (31P)
NOTE: Standard battery voltage is 12 V.
1AFS]TC2
]GP23IGPl^:^ I -:,6AFS+1
CKPIKS
'10
SG2t112ACV15TPST6AFS_18
VSS
19IVAP2Avcc221vccl
22
HTC+
23LG225CMPA
26CMPB(rDc)
27tGPts,l28rcPts329tGPts230GPLS 1
Wire side ol female terminals
Terminalnumb€rWho colorforminal nameDescriptionSignal
ELKAVHTAFSHTC (AIR FUEL RATIO(4./F)SENSOR HEATERCONTROL}
Drives Ay'F sensor heaterWith ignit'on switch ON {ll): battery voltageWith fully warmed up engine runnang: 0 V
2YEUBLKIGP2 (POWEB SOURCE)Power source for the ECMcircuitWith the ignition switch ON 1ll): battery voltageWith the ionition switch OFF: about 0 V3YEUBLKIGPl {POWER SOURCE)Power source for the ECMWith the ignition swatch ON {ll): battery voltageWith the ionition switch OFF: about 0 V4BLKPG2 (POWER GROUNDGround forthe ECM circuitLess than 1.0 V at all times5BLKPG1 (POWER GROUNDGround forthe ECM circuitLess than 1.0 V at all times6REDAFS + (AIR FUEL RATIO(A,/F}SENSOR, SENSOR 1+ stDE)
Detects Ay'F sensor{sensor 1) signal
18LUCKP (CRANKSHAFTPOSITION SENSOR)Detects CKP sensor signalWith engine running: pulses
9BED/BLU)K SENSOB)Detects knock sensor siqnalWith enqine knocking: pulses10YEL2 {SENSOR;ROUND);ROUND)Sensor qrounrLessthan 1.0V at elltimesG1 {SENSORSensor qroun(Lessthan 1.0V at alltimes12BLIVREDIACV (IDLE AIR CONTROL(IAC)VALVE)Drives IAC valveWith engine runningr duty controlled
RED/BLKTPS (THROTTLE POSITIONSENSOR)Detects TP sensor signalWith throttle fully open: about 4.8 VWith thronle fullv closed: ahout 0-5 VREDI/ELAFS (AIR FUEL RATIO(4,/F)SENSOR, SENSOB 1SIDE)
Detects !y'F sensor(sensor 1)signal
18WHT/GRNVSS (VEHICLE SPEEDSENSOR)Detects VSS signalWath ignition switch ON (lli and front wheelsrotating: cycles from about 0 V to about 5 V or
(cont'd)
11-19

Fuel and Emissions Systems
System Descriptions {cont'd)
ECM Inputs and Outputs at Connector A (31P)
\. il
Wire side of female terminals
\.
1AFS]TC2
GP2
3IGPl4PG25PG.16AFS+1
CKP
IKS
10SG211sG1
12IACV
'15
TPS16AFS_18
VSS
19IVAP20vcc221vccl
22AFSHTC+
23LG225
Ct\.4PA
26CMPB(rDc)
27IGPLS428IGPLS329IGPLS230IGPLS,I
NOTE: Standard battery voltage is 12 V.
JorminalnumberWirecolor[€rminal namoDescriptionSignal
19GRN/REDMAP (MANIFOLDABSOLUTE PRESSURESENSOR)
Detects MAP sensor signalWith ignition switch ON (ll):about3 VAt idle: about 1.0 V (depending on enginespeed)
20YEUBLUVCC2 (SENSOR VOLTAGE)Provides sensor voltageWith ignition switch ON {ll): about 5 VWith ionition switch OFF: about0V21YEUREDVCC] (SENSOB VOLTAGE)Provides sensor voltageWith ignition switch ON {ll): about 5 VWith ionition switch OFF: about0V22AFSHTC - (AIR FUELRATIO (A"iFiSENSORHEATER CONTROL + SIDE)
Detects a,/F sensor heatervoltageWith ign;tion switch ON lll): banery voltage
23BRN?ryE LLG2 (LOGIC GROUNDround for the ECM circuLessthan 1.0 V at alltimes24BRN?ryE L1(Lround for the ECM circuLess than '1.0 V at alltimes25B LU,^/VHTCMP A (CAMSHAFT
POSITION SENSOR A)Detects CMP sensor AstonalWith engine running: pulses
26GRNCMP B CAMSHAFTPOSITION (CMP)SENSOBB (TDC (TOP DEAD CENTERSENSORi)
Detects CMP sensor 8 (TDc
sensor)With engine running: pulses
27BRNIGPLS4 {No. 4IGNITIONCOIL PULSE)Drives No, 4 ignition coiWith ignition switch ON (ll)r about 0 vWith engine running: pulses28WHT/BLUIGPLS3 {No.3IGNITIONCOIL PULSE)Orives No.3 rgnition coi
29BLU/REDlGPLS2lNo.2 IGNITIONCOIL PTJLSE)Drives No.2 ignition coil
30YEUGRNIGPLSI (No. 1 IGNITIONco

PlltsF)Drives No. I ignition coil
11-20
\.
a
a

Wire side o{ female terminals
NOTE: Standard baftery voltage is 12 V.
Terminalnumo€tWire color[erminal nameDescriptionSignal
BLUAvHTVTC+ lVTC OIL CONTBOLSOLENOID VALVE +SIDE)Drives VTC oilcontrolWith ignition switch ON (ll): 0 V
2lNJa {No. 4INJECTOR)Driveso. 4 iniectorAt idle: duty controlled
3BLJo.3INJECTORIDriveso.3 iniector4R1)TOR)Driveso.2 iniector
5BRNlNJl 1No. I INJECTOR)Drives No. 1 iniector
6GRNFANC (RAOIATOR FANCONTROL)Drives radiator fan relayWith radiator fan running: about 0 VWith radiator fan stopped: batterv voltaoe
7GRN/vVHTRVS (REVERSE LOCKSOLENOID VALVE)Drives reverse lock solenoidWith vehicle speed below 9.4 mph (15 km/h):battery voltageWith vehicle speed above 12.5 mph (20 km/h): 0 V
8REDAVHTECT (ENGINE COOLANTTFMPFRATURE SENSOR)Detects ECT sensor signalWith the ignition switch ON (ll): about 0.1 4.8 Videoendino on enoine coolant temDerature)
9BLU/BLKVTPSW (VTEC OILPRFSSTIRF SWITCH)Detects VTEc oil pressureswitch sionalWith engine at low engine speed: about 0 .Wirh enoine at hioh enoine soeed: batterv voltaqe
10WHT/BLUALTL (ALTEBNATOR LSIGNAI IDetects alternator L signalWith ignition swit'ch ON (ll): about 0 VWhh enoine runnino: batterv voltaqe
WHT/REDALTF (ALTERNATOR FRSIG NALIDetecls alternator FB signalWith engine running: about 0 V- 5 V{deoendinq on electrical load)
GRN/YELVTS {VTEC SOLENOIDDrives VIEC solenoid valveAt idle: about 0 V
'17REDI/ELIAT (INTAKE AIRTEMPERATURE SENSOR)Detects IAT sensor signalWith ignition switch ON {ll): about 0.1 V 4.8 vl.lcnen.iino on intake air temoerature)
18WHT/GRNALTC (ALTERNATOR
CONTROL)Sends alternator controlWith engine running: about 0 V 5 V(.lcocn.lino on electrical ioad)
21YEUBLUPCS {EVAPORATIVEEMISSION CANISTERPURGE VALVE)
Drives EVAPcanister purgevalveWith engine running, engine coolant below 149'F
165'C): battery voltageWith engine running, engine coolant above 149'F165"C): dutv controlled
23BLK/Vr'HTVTC (VTC OIL CONTROLSOI FNOID VALVE SIDE)Drives VTC oilcontrolWith the ignition switch ON (ll): 0 V
(confd)
11-21

Fuel and Emissions Systems
System Descriptions (cont'dl
ECM lnputs and Outputs at Connector E (31P}
L
u
1iMoFPR
2sr-{]zs3LG34SG3
6$1025HTC
1M RLY
8AFSHTCR
I
14FTP15ELD
16EPSLD
18ACC20Z/VBS21VSV
22BKSW23K-LINE24SEFMJ26NEP
21rMoCD
29scs30WEN31MIL
Wire side of female terminals
NOTE: Standard battery voltage is '12 V.
TerminalnumberWire colorferminal nameDescription Signal
GRNI/ELIMO FPR (IMMOBILIZERFLJEL PUMP RELAYIDrives PGM Fl main relay 20Vfor2 seconds after turning ignition switch ON{ll). then batterv voltaoe2WHT/REDSHO2S (SECONDARYHEATED OXYGEN SENSOR(SECONDARY HO2S),SENSOR 2r
Detects secondary HO2S{sensor 2) signalWith throttle Jully opened from idle with fullywarmed up engine: above 0.6VWith throttle quickly closed: below 0.4 V
3BRN/YELLG3 (LOGIC GROUND)cround forthe ECM/PCMcontrolcircuitLess than 1.0 V at all times
4PNKSG3 {SENSOR GBOUND)Sensor oroundLess than 1.0 V at all times5YEUELUVCC3 {SENSOR VOLTAGE)Provides sensor voltageWith ignition switch ON (ll): about 5 VWith ionition switch OFF: about 0 V6BLKATr'HTSO25HTC (SECONDARYHEATED OXYGEN SENSOR(SECONDARY H02S)HEATER CONTROL)
Drives secondary HO2SheaterWith ignition switch ON (ll): baftery voltageWilh fullv warmed up engine running: dul,controlled
1REDA/ELMRLY (PGM.FI MAINRELAY}Drives PGM-Flmain relay 1Power source forthe DTCWith ignition switch ON (ll): about 0 VWith ignition switch OFF: battery voltage
IORNAFSHTCR {AIR FUEL BATIO(Iy'F)SENSOR HEATERCONTROL RELAY)
Drives air fuel ratio sensorheater relayWith ignition swirch ON {ll): 0 V
IYEUBLKIGl (IGNITION SIGNAL)Detecrs ignition signalWith ignition switch ON (ll): battery voltageWith iqnition switch OFF: about 0 V't4LT GRNFIP lFUEL TANKPRESSURE (FTP) SENSOR)Detects FTP sensor signalWith ignition switch ON (ll) and fuel fill cap open:about 2.5 VGRN/REDELD (ELECTRICAL LOADDETECTOF)Detects ELD signalWith ignition swjtch ON itt):aOoutO.t V l-gV(deDendino on electrical load)LT GRN/8LKEPSLD (ELECIRICALPOWEB STEEBING LOADDETECT)
Detects Power steering loadsrgnalAt idle with steering wheel in straight aheadposition: about 0 VAt idle with steering wheelatfull lock: momentary
'18REDACC (Ay'C CLUTCH RELAY)Drives P,/C clutch relayWith compressor ON: about 0 VWith comoressor OFF: batterv voltaoe
11-22
\-

ECM Inputs and Outputs at Connector E (31P)
ltMoFPR
2$.c2s
i6SFIO2SHTC
1
IV RLY
IAFSHTCR
9tGl
14FTP15ELD
16EPSLD
t8202,4/BS21VSV
22BKSW23K LINE24SEFMJ26NEP
21lvoCD
29scs30WEN31MIL
Wire side of female terminals
NOTE: Standard battery voltage is 12 V.
TerminalWire colorTerminalnameDescriptionSignal
20BLU/RED2WBS (EVAPORATIVEEMISSION (EVAP)BYPASSSOLENOID VALVE)
Drives EVAP bypass With ignition switch ON (ll): baftery voltagesolenoid valve
21LT GRN/REDVSV (EVAPORATIVE
EI\4ISSION iEVAP)CANISTEB VENT SHUTVALVE)
Drives EVAP canister ventshut valveWith ignilion switch ON (ll): battery voltage
22WHT/BLKBKSW lBRAKE PEDALPOSITION SWITCH)Detects brake pedaloosition switch sionalWith brake pedal released: about 0 VWith hrake nedal nresse.l: batterv voltaoe23LT BLUK-LIN ESends and receives scanWith ignition switch ON (li)r pulses or battery
YELSEFMJCommunicates withmrltinleY eontrol unitWith ignition switch ON (ll): about 5 VWith enoine runnino under load: DUlses26BLUNEP (ENGINE SPEEDPULSE)Outputs engine speed pulseWith engine running: pulses
21RED/BLU \40CD fl\4MOBTLTZERCODE)Detects imrnobilizer signal
29BRNSCS (SERVICE CHECKSIGNAL)Oetects service check signalWith the service check signal shorted with the PGMTester: about 0 VWiih rhe service check sional ooened: about 5 V
30RED,A/VHTWEN (WRITE ENABLESIGNALiDetects write enable signal With ignition switch ON (ll): about 0 V
GRN/ORNMIL (MALFUNCTION
INDICATOR LAMP)Drives N4lLWith MIL turned ON: about 0 VWith MIL turned OFF: batterv voltaqe
(cont'd)
11-23