2000 HONDA CIVIC Valve

3.
5.
6.
1.
Fuel Cut-off Control
. During deceleration with the throttle valve closed, current to the fuel injectors is cut off to improve fuel economy at
speeds over the following rpm:. D16Y5 engine (M/T):850 rpm. D]6Y5 engine (CVT), D'16Y8 engine (USA M/T): 920 rpm
. Dl6Y8 engine (USA A,/I), D16Y7 engine (USA A,/T);910 rpm
. D16Y8 engine (Canada M/T), D16Y7 engine (canada): 990 rpm
' D16Y8 engine (Canada M/T): 1,000 rpm
. 816A2 engine: 970 rpm
. Fuel cut-off action also takes place when engine speed exceeds 6,900 rpm (D16Y5, D16Y7 engine; D'16Y8 engine:
7,000 rpm. 816A2 engine: 8.100 rpm), regardless of the position of the throttle valve, to protect the engine from
over-rewing. With '99 Dl6Y7 engine (A,/T) and '99 D16Y8 engine (A./T), the PCM cuts the fuel at engine speeds over
5,000 rpm when the vehicle is not moving.
IVC Compressor Clutch Relay
When the ECM/PCM receives a demand for cooling from the air conditioning system, it delays the compressor from
being energized, and enriches the mixture to assure smooth transition to the A,/C mode
Evaporative Emission (EVAP) Purge Control Solenoid Valve*'
When the engine coolant temperature is above 154'F (68'C). the ECM/PCM controls the EVAP purge control solenoid
valve which controls vacuum to the EVAP purge control canister.
Evaporative Emission (EVAP) Purge Control Solenoid Valve*a
When the engine coolant temperature above 154"F (68"C), intake air temperature above 32"F (0'C) and vehicle speed
above 0 mile (0 km/h) or [Ay'C compressor clutch on and intake air temperature above 160"F (41'C)], the ECM/PCM
controls the EVAP purge control solenoid valve which controls vacuum to the EVAP purge control canister.
Exhaust Gas Recirculation (EGR) Control Solenoid Valve*?
When EGR is required for control of oxides of nitrogen (NOx) emissions. the ECM controls the EGR control solenoid
valve which supplies regulated vacuum to the EGR valve
Alternator Control
The system controls the voltage generated at the alternator in accordance with the electrical load and driving mode,
which reduces the engine load to improve the fuel economy.
ECM/PCM Fail-safe/Back-up Functions
1. Fail safe Function
When an abnormality occurs in a signal from a sensor, the ECM/PCM ignores that signal and assumes a pre-pro-
grammed value for that sensor that allows the engine to continue to run.
2. Back-uD Function
When an abnormality occurs in the ECM/PCM itself, the fuel injectors are controlled by a back-up circuit independent
of the system in order to permit minimal driving.
3. Self diagnosis Function lMalfunction Indicator Lamp (MlL)l
When an abnormality occurs in a signal from a sensor, the ECM/PCM supplies ground for the lvllL and stores the DTC
in erasable memory. When the ignition is initially turned on, the ECM/PCM supplies ground for the MIL for two sec-
onds to check the MIL bulb condition.
4. Two Trip Detection Method
To prevent false indications, the Two Trip Detection Method is used for the HO2S, fuel metering-related. idle control
system, ECT sensor, EGR system and EVAP control system self-diagnostic functions. When an abnormality occurs,
the ECM/PCM stores it in its memory. When the same abnormality recurs after the ignition switch is turned OFF and
ON 0l) again, the ECM/PCM informs the driver by lighting the MlL. However, to ease troubleshooting, this function is
cancelled when you jump the service check connector. The MIL will then blink immediately when an abnormality
occurs,
5. Two (or Three) Driving Cycle Detection Method
A "Driving Cycle" consists ot starting the engine. beginning closed loop operation, and stopping the engine. lf misfir-
ing that increases emissions is detected during two consecutive driving cycles, or TWC deterioration is detected dur-
ing three consecutive driving cycles, the ECM/PCM turns the MIL on. However, to ease troubleshooting, this function
is cancelled when you jump the service check connector. The MIL will then blink immediately when an abnormality
occurs.
(cont'd)
1 1-1 05
.1.

PGM-FI System
Engine Control Module/Powertrain Control Module (ECM/PCMI
('96 - 98 Models,'99 - 00 Dl6Y5 engine with M/Tl (cont'd)
NOTE:. When there is oo Diagnostic Trouble Code (DTC) stored, the MtL wi

stay on if the SCSservace connector is connected and the ignition switch is on,. lf this symptom is intermittent, checklor:- A loose Fl E/M 115 A) fuse in the under hood luse/relay box- A loose No. 13 FUEL PUMP fuse (15 A) in the underdash fuse/relay box- An intermittent shon in the wire between the ECM/PCM (C7) and the service cnecKconnector- An intermittent short in the wire between the ECM/PCM (A18) and the gaugeassembly- An intermittent shon in the wire between the ECM/PCM {D4) and the MAp sensorAn intermittent short in the wire between the ECM/PCM (D10), the Tp sensor, theEGR valve l:ft sensor (D16Y5 engine) and/or the Fuel tank pressure sensor (,96Dl6Y8 engine (coupe), '97 016Y7 engine (coupe: KL model, sedan: KL (LX) modeli,'97 016Y8 engine {coupe: all models, sedan: KL modeti,'98,all models}- PGM-FImain relay. See the OBD ll scan tool or Honda PGM Tester user's manuals lor specitic operatinginstructions.
ECM/PCM CONNECTOR C 13lPI
Wire side of female terminals
(To page 11 109)
(To page 11,109)
11-108
The Maltunction Indicator Lamp(MlLl stays on o. comes on eftartwo s€conds,
Check the Oiagnoslic TroubleCode {DTC}I1. Connect a scan tool or HondaPGM Tester.2. Turn the ignition switch ON (ll).
3. Read the DTC with the scantool or Honda PGM Tester.
Go to troubleshooting p.oc€dur€s(se€ pago 11{11.Are any DTC{s) indicated?
Check the DTC by MIL indication:1. Turn the ignition switch OFF.2. Connect the SCS service con,nector to the service checkconnector.3. Turn the ignition switch ON (lli.
Repair opon ol short in wirebotwoen the ECM/PCM (C8)
and Data Link Connector.Go to troublelhooting proce-dure ls6e page 11-811.
Does the MIL indicate any DTC?
Try to start the engine.
Does the engine start?
Check for a short in the wire(SCS lin€l:1. Disconnect the SCS serviceconnector.2. Stop the engine and turn theignition switch ON {lli.3. Measure voltage between theECM/PCM connector terminalC7 and body ground.
Ropair short to body Iround inthe wire betweon ECM/PCM lCTland sorvice check connector.
ls there approx. 5 V?
scs tBRNI

lFrom page 11 108)
Check for a short in the wire {MlLlinell1. Turn the ignition switch OFF.
2. Disconnect the Eclvl/PCM con-nector A (32P).
3. Turn the ignition switch ON {ll).
Ropair short to body gtound in
the wir. between the ECM/PCM
lA18) and MlL.ls the MIL ON?
Substitute a known-good ECM/
PCM and recheck. lt 3ymptom/indicaiion goes away, rePlace
ihe original ECM/PCM.
(From page 11 108)
Inspect Fl E/M (10 A) fuse in theundeFhood Iuse/relay box.
- Repair short in the wirg
b€tweon Fl E/M (15 A) luse
and PGM-FI main rolay.- Replace Fl E/M (15 Alfuse.
Inspect No. 13 FUEL PUMP (15 A)
fuse in the under-dash fuse/relaY
- Repait lhort in the wire
botween No. 13 FUEL PUMP
115 Al fuse and PGM-FI main
reray.- Roplace No. 13 FUEL PUMP115 Al tu3o.
Check for a short in a 3€nsor:1. Turn the ignition switch ON (lli.
2. Disconnecl the 3P connectorfrom each sensor one at time:
. TP sensor. EGR valve lift sensor (D16Y5
engrne). Fuel tank pressure sensor('96 D16Y8 engine (coupe),'97 D16Y7 engine (couPe:
KL model, sedan: KL (LX)
model),'97 D16Y8 engine
lcoupe: all models, sedan:KL model,'98-all models)
{To page 11 110)(cont'd)
1 1-109
!

PGM-FI System
(From page 11-109)
Replace the sensor that causedthe light to go out.Does the N4lL go OFF?
Check fo. a short in the wi.os(VCC lines):':. Turn the ignition switch OFF.2. Disco n n ect the ECM/PCMconnector D (16P).
3. Check for continuity betweenbody ground and ECM/PCMconnector terminals D4 andD10 individually.
Ropair short to body groundin the wire betweon ECM/PCM {O4) and MAP s6n3or.Repair short to body groundin the wire between ECM/PCM lD10l, the TP sensor, theEGR valve lift sensor {D16Y5engine) and/or the Fuel tankpressure sensor {'96 Dl6Ygengine lcoupe),'97 D16Y7engine (coupe: KL model,sedan: KL (LXl model), '97
D16Y8 engine (coupe: allmodels, sedan: KL model. €8-allmodelsl.
ls there continuity?
Check tor rn open in the wires(lGP lines):1. Disconnect the fuel injectorsand IAC valve connectors,2. Turn the ignition switch ON (ll).3. Meas u re voltage betweenbody ground and ECM/PCMconnector terminals A11 and424 indivjdually.- Repair open in the wirels)between ECM/PCM (A11,A24land PGM-Fl main relay.- Check for poor connectionsor loose wiras at the PGM-FImain relay,- Test the PGM-FI mdin relavlsee pag6 11-237).
ls there battery vohage?
Check for an open in the wires(LG line3):1. Reconnect all sensor connectors.2. Reconnect the ECM/PCM con-nector D (16P).
3. Turn the ignition switch ON (ll).4. Measure vo ltage betweenbody ground and ECM/PCMconnector terminals Ag andA22 individually.
Repair open in the wirolglb€twe€n ECM/PCM {A9, A22} andG101 that had more than 1.0 V.
ls there less than 1.0 V?
Substitute 6 known-good ECM/PCM and r€check. lf symptom/indication 9o€s away, replacethe original ECM/PCM.
Engine Control Module/Powertrain Control Module (ECM/pCMl
('96 - 98 Models, '99 - 00 D16Y5 engine with M/Tl (cont,dl
ECM/PCM CONNECTOR D {16P}
Wire side of female terminals
ECM/PCM CONNECTOR A (32P}
Wire side of female terminals
11-110
LG1
VCCl {YEL/RED}
IGP 1{YEL/BLKI
2I11
1213l5t6Itt8t9202321
25272a2930
IGP 2(YEL/BLKIv) (l
{8RN/BLK)
I258tol1'12tt11t5l617t8t920232a
2A2330
LG2{8RN/8LK}

Engine Control Module/Powertrain Control Module (ECM/PCM)
('95 - 00 Models except Dl6Y5 engine with M/T)
NOTE:. When there is no Diagnostic Trouble Code lDTC) stored, the MIL will staY on if the SCS
seruice connector is connected and the ignition switch is on.. lf this symptom is intermittent, check for:- A loose No. 25 (METER) {7.5 A) fuse in the underdash fuse/relay box- A loose Fl E/M (15 Alluse in the undeFhood fuse/relay box- A loose No. 13 FUEL PUMPfuse (15 A) in the under-dash fuse/relay box- An intermittent shon in the wire between the ECM/PCM (A18) and the gauge assem'
- an intermittent short in the wire between the ECM/PCM (C19) and the MAP sensor- An intermittent short in the wire between the ECM/PCM {C28), the TP sensor, the
EGR valve lift sensor (D16Y5 engine) and/or the Fuel tank pressure sensor ('96 D16Y8
engine (coupe),'97 D16Y7 engine lcoupe: KL model, sodan: KL (LX) model)"g7
Dt6Y8 engine (coupe: all mod;ls, sedanl KL model),'98-all models,'99-al' models''00-all models.- PGM'FI main relay. See the oBD ll scan tool or Honda PGM Tester user's manuals for specific operating
instructrons,
ECM,/PCM CONNECTOR A I32PI
Wire side of {emale terminals
The Mrlfunction Indicator LamP{MlL) never comes on {even tor
two seconds) after ignition is
turned ON lll).
Turn the ignition switch ON lll).
- Repair shott or open in thowire bstwoon No. 25 IMETER)l?.5 A)tuse and gauga tsom_blv.- Reolace No. 25 (METERI (7.5
Alluse.
ls the low oil pressure light on?
Try to start the engine.
Check for an opon in the wire orbulb (MlL line):1. Turn the ignition switch OFF.2. Connect the ECM/PCM con'
nector terminal A18 to bodyground with a iumper wire.
3. Turn the ignition switch ON (ll)
Does the engine start?
- Repair open in tho wire3
betwoon ECM/PCM (A18) andgaugo .*tembly.- Rool.ce the MIL bulb.
Substitute a known-good ECM/
PCM and rochoc&. lf sYmptom/indication goes sw6y, repl.ce
tho original ECM/PCM.Turn the ignition switch OFF.Inspect Fl E/M (15 A)fuse in theunderhood Iuse/relay box.
Rop.ir short in the wirc
betwo€n Fl E/M (15 A) luso
and PGM-Fl mrin rGl.y.Reol.ce Fl E/M (15 A)tusa.
lnspect No. 13 FUEL PUMP {15 A}
luse in the under-dash fuse/relay
- Reoair short in the wiro
between No. 13 FUEL PUMP
115 Al luse sod PGM-FI mainrelay.- Reolace No. 13 FUEL PUMP115 A) tuse.
(To page 11 112)
(cont'd)
11-111
.f,

PGM-FI System
(From page'11-111)
Check loi an open in the wires(lGP linesl:1. Disconnect the lueliniector andIAC valve connectors.2. Turn the ignition switch ON (ll).
3, Measu re voltage betweenbody ground and ECM/PCMconnector terminals 81 andBg individually.
- Repair open in the wiro(3)between ECM/PCM lBl, B9land PGM-Fl main relay.- Check tor poor connectionsor loose wires al the PGM-FImain relav.- Test tho PGM-FI main rehy(3.e page 11-237).
ls there battery voltage?
Check tor an open in the wires(PG, LG lines):1. Reconnect the fuel iniectorand IAC valve connectors.2. Measure voltage betweenbody ground and ECM/PCMconnector terminals 82, 810,820 and 822 individually.
Repair open in the wirels)between ECM/PCM and G 101llocated ai the l6ft side of thointaks m.nifoldl thrt h.d morethan 1.0 V.
ls there lessthan 1.0 V?
Check for a short in the wires
{VCCI, VCC2 lin6s}:Measure voltage between bodyground and ECM/PCM connectorterminals C19 and C28 individually.Check toa a 3hort in s 3ensor:While measuring voltagebetween body ground and ECM/PC[/t connector terminals C19and C28 individually, disconnectthe 3P connector of each sensorone at time:. MAP sensor. TP sensor. EGR valve. Fueltank pressure sensor
ls there approx.5 V?
Reoair short in lhe wire betwe.enMAP 3ansor, TP sensor, EGRvalve, Fuel tank pres3ure 3ensorand ECM/PCM {Cl9, C28).
ls there approx. 5 V?
Substiiute a known-good ECM/PCM and racheck. ll symptom/indicetion goes eway, replaceth6 original ECM/PCM.Replace tho sansor that had.pprox. 5 V.
Engine Control Module/Powertrain
('99 - 00 Model except Dl6Y5 (M/Tl
Module (ECM/PCM)
(cont'd)
Control
engine)
ECM/PCM CONNECTOR B {25P)
LG1 (BRN/BLKI
Wire side of female terminals
ECM/PCM CONNECTOR C (31P)
female terminalsvcc2IYEL/BLUIvccl{YEL/RED)
Wire side of female terminals
11-112

PGM-FI System
Throttle Position ITP) Sensor ('96 - 98 Models,'99 - 00 D16Y5 engine with M/Tl
The scan tool indicates Diagnostic Trouble Code (DTC) P0122: A low voltage problem in the Throttle Position(TP) sensor circuit.
The TP Sensor is a potentiometer. lt is connected to the throttle valve shaft. As the throttle position changes, the throttleposition sensor varies the voltage signal to the ECM/PCM.
OUTPUT VOLTAGE IVI
1
2
1
0
s{i2(GRN/BLKI
THROTTLEOPENING
FULLTHROTTLE
TP SENSOR 3P CONNECTOR ICllOI
vocz(YEL/BLUI
Wire side ot femal6 terminals
ECM/PCM CONNECTOR D IT6PI
SG2 IGRN/ALKI
{To page l1-133)
Terminal side of male terminals
11-132
- Tho MIL h63 boon roportod on.- DTC m122 i. storcd.
Probl6m voritic€tion:1. Turn the ignition switch ON (ll).
2. Check the throttle positionwith the scan tool.
ls there approx. .49 V whenthe throttle is fully closed andapprox. 4.5 V when the throttleis lully op6ned?
Int..mittent tailura, rFiem ir OKat thit tima. Chock tor Door con-nections or loorc wires !t C110ITP lonrorl .nd ECM/FCM.
Ch6ck lor rn opon in the wire(VCC2linel:
1. Turn the ignition switch OFF.2. Disconnect ths TP sensor 3Pconnector.3. Turn the ignition switch ON lll).4, Measure voltage betweenthe TP sensor 3P conn€ctor ter-minals No. l and No.3.
ls there approx. 5 V?
Check for rn opcn in wire IVCC2line):Measure voltage between ECM/PCM conneclor terminals D10 and011.Chock for rn open or 3hort in TPlon30t:1. Turn the ignition switch OFF.2. At the s€nsor side, measureresistance between the TP sen-sor terminals No. 1 and No. 2with the throttle fully closed.
Roplir op€n in thg wiro batwcsnECM/PCM {DlO) rnd TP ren3or.ls there approx.5 V?
Substitut6 r known-good ECM/PCM and rach6ck. lf pro$ribodvohrge i! now avrilablc, replac€tho o.iginel €CM/FCM.
Wire side of female terminals

PGM-FI System
Throttle Position (TPl Sensor ('99 - 00 Models except D16Y5 engine with M/T)
lTO12Z _TI scan tool indicates Diaqnosttc Trouble Code (DTC) P0122: A low voltage problem in the Throttle position- { | r, sensoa crrcurl.
The TP Sensor is a potantiometer. lt is connected to the throttle valve shaft. As the throttle position changes, the throttleposition sensor varies the voltage signal to the ECM/PCM.
ERUSHHOI.DENOUTPUT VOLTAGE (VIBRUSH
BESIS?OF
TERi'I AL
5
4
3
2
1
o
INNERBUS}IINGTHROTTLEOPE II{G
FULLTHROTTLE
TP SENSOR 3P CONNECTOR {Cl1OI
sG2IGRN/8LKIvcc2(YEUBLUI
Wire side of temale terminals
ECM/PCM OONNECTOR C 131P)
Ch.Gk for rn opan or 3hort in TP36nlot:1. Turn the ignition switch OFF.2, At the sensor side, moasureresistance between the TPsensor 3P connector terminalsNo. 1 and No. 2 with th€ throt,tle fully closed.
(To page 11-135)
- Th. MIL har boon.6portcd on.- DTC P0122 b siored.
Problem verification:1. Start the engine, Hold theengine at 3,000 rpm with noload (in Park or neutral) untilthe radiator fan comes on.then turn the ignition switchOFF,2. Turn the ignition switch ON (ll).3. Check the throttle positionwith the scan tool.
ls there approx. .49 V whenthe throttle is fully clos€d andapprox, 4.5 V when the throttleis fully opened?
l||t rmittont failura, lyrtom b OKat thi! tima. Chock tor poor con-nactionr o. looao wires rt C110{TP 3.n!or} rnd ECM/PCM.
Check for an opan or 3hort in thowi.c (VCC2 linc):1. Turn the ignition switch OFF.2. Disconnect the TP sensor 3Pconnector,3. Turn the ignition switch ON (ll).4. Measure voltago betweenthe TP sensor 3P connector terminals No. 1 and No.3.
ls thero approx. 5 V?
Chccl tor .n opln in wiro IVCC2lin€l:Mgasure voltago between ECM/PCM connector terminals C18 and
R.prir opcn in the wiro bctw.enECM/PCM (C281 and TP 3€nror.ls there approx. 5 V?
Subrtituto r known-good ECM/PCM .nd rochcck. lf pro.c.ibedvoltaga i! now available, roplacotho origin.l ECM/PCM.
Wire side ol female terminrls
Terminal side of male terminals
11-134
L