2000 HONDA CIVIC Air idle

PGM-FI System
Primary Heated Oxygen Sensor (Primary HO2SI (sensor l)
(Dl6Y5 engine with M/T) (cont'd)
(From page 1l-147)(From page 11 147)
(To page 11 149)
{GRN/BLK}
(GRN/8I-K}
(To page 11-149)
11-148
Substitute a known-good ECMand rechock. tf symptom/indicr-tion goes away, replace the origi-nalECM.
Check for a short in the wire llP+lin6):1. Disconnect the 8P connectorIrom the Primary HO2S (Sen-
sor 1).2. Check tor continuity betweenbody ground and ECM connec-tor terminal C25.
Repair short in the wiro botweenthe Primarv HO2S {Sensor 1} andECM {C25}.
Replace th€ Primary HOzS {Sen-sor 11.
| 2 3ra1a9to
tl 12t516111a
p ffi;r, w''.""i0"or.I lemate lerml
ls there more than 5.0 V?check the EcM:1. Turn the ignition switch OFF.2. Disconnect the 8P connectorfrom the Primary HO2S (Sen-
sor 1).3. Turn the ignition switch ON (ll).4. Measure voltage between ECN4connector C25 and D11.
ls there more than 5.0 V?
Check the ECM input voltage llP-/vS-linel:1. Start the engine. Hold theengine at 3,000 rpm with noload (transmission in neutral)untilthe radiator fan comes on,then let it idle.2. Measure voltage between ECMconnector terminals C24 andDt1.
Subslitute a known-good ECMand rgcheck. It symptom/indica-tion goes away, repl.ce the origi-nal ECM.
ls there 2.6 2.8 V?Check th6 ECM output voltage(VS+ linel:Measure voltage between ECMconnector terminals C25 and D11.
7a9t0It 12t3t6'11ta
VS+{WHT}sG2
235
,9 ,101l12
l3'tat515
1 2i35a9t0't2'ttt5ttrl22
VS+{WHT)sG2
23
6lt9ll1315

PGM-FI System
I
a
a
Ch6ck the PO2SHTC circuit:1. Start engine and keep enginerpm at idle.2. At the engine wire harness,measure voltage betweenPrimary HO2S (Sensor 1) 8Pconnector terminal No. 1 terminal and body ground.
Check for an open in the wire(PG linellMeasurc voltage between PrimaryHO2S (Sensor 1) 8P connector ter-minals No. l and No.2.
ls there morethan 5 V?
Repair opon in the wi.o bEtwoonthe HO2S.nd G101 (located atth.rmonat housingl.
ls there more than 5 V?
Substitule a known-good ECM.nd .echeck. lt 3ymptom/indica-tion 906! rwry, roplace the origi-nal ECM,Check lor a short in the wire
{PO2SHTC line):1. Turn the ignition switch OFF.2. Disconnect ECM connector A(32P)trom the ECM.3. Check for continuity betweenECM connector terminal 46and body ground.
Ropair 3hort in tho wire betwoenthe ECM {46} and the Prim.ryHO2S lson3or 11.
Check for an open in the wire(PO2SHTC linel:Check for continuity betweenECM connector terminal 46 andthe Primary HO2S (Sensor 1)8Pconnector terminal No. 1.
Repair opsn in the wir6 botweenECM {A6} .nd the Primary HO2Slsonror 1).
Substituto a known-9ood ECMand rech6ck. lf symptom/indica-tion goes away, replace the origi-nal ECM.
Heated Oxygen Sensor (HO2S) Heater (Dl6Y5 engine with M/Tl (cont'd)
(From page 11-161)PRIMARY HO2S (SENSOR 1} 8P CONNECTOR {Cl45I
PO2SHTC{BtK/WHT)
PO2SHTCIALK/WHTI
ECM CONNECTOR
female terminals
11-162
\.
!
\
A {32P}
o
6I9l roIt
12t3l5t61't8t9a221 232a
252'2aEito,1| ---

PGM-FI System
Knock Sensor (KSl ('96 - 98 D16Y5 engine with CW and'96 - 98 D16Y8
engine)
Forr-l I,3,.""""
tool indicates Diagnostic Trouble Code (DTC) P0325: A malfunction in the circuit of the Knock sensor
DIAPHRAGM
ECM/PCM CONNECTOR D {16PI
KS 2P CONNECTOR (Cl371
KS(RED/BLUI
KSIRED/BLU)
The MIL has bgen roportsd on.DTC PO:t25 is stored.
Problom veiilication:1. Do the ECM/PCM Reset Proce-oure,2. Start the engine. Hold theengine at 3,000 rpm with noload (in Park or neutral) untilthe radiator tan comes on,then let it idle.3. Hold the engine at 3,000 -
4,000 rpm tor at least 60 sec-onds.
Intermittenl fsilu16, 3y3l6m b OKat thi3 timg lteat drivo mav banoc63saryl.Chock tor poor conneclioni orloose wire3 b€twccn C137 {knocklen3or (KS)l and ECM/PCM.
ls DTC P0325 indicated?
Check for a short in tho wire {KSlinel:1. Turn the ignition switch OFF.2. Disconnect the knock sensor2P connector,3. Discon n ect the ECM/PCMconnector O (16P).
4. Check for continuity betweenECM/PCM connector termi-nals D6 and body ground.
Reo.ir 3hort in the wire betweenECM/PCM {DG) .nd knock 3.n-
Chock for an open in the wire(KS linel:Check for continuity betweenECM/PCM connector torminal D6and knock sensor 2P connectorterminal No. l.
Ropair open in the wire bgtweonECM/PCM lD6l and knock sen-3('t.ls there continuity?
Substitute a known-good knocksensor and recheck.
Rsplace th. o.igin.l knock s€nsor.
Substitute a known-good ECM/PCM end recheck. lf 3ymptom/indication goes rway, replacerhe original ECM/PCM.
Wire side of female terminals
1\
I
tert
,_-
eslnini
,--tl
le oI temrlsal€
121
189't01t12
13l4t5t6
11-170

Elestrical Load Detector (ELD) f96 - 98 Models''99 - 00 D16Y5 engine with M/T)
ThescantoolindicatesDiagnosticTroubleCode(DTC)P1298:AhighvoltageproblemintheElectricalLoad
Detector (ELD) circuit
ELD 3P CONNECTOR {G's'I
Wire side ol female terminals
EL IGFN/REDI
Problom vcrificttion:
1. Do the EcM/PClVl Reset Pro-
cedure,2. Start the engine.
3. Turn on headlights.lntarmitt..rt l.ilur., ryttcm b OK
.t thia tim. Ch.ck lor Poo' con-
nections or looaa wir.3 at C131
lbcd.d und.r right ide ol dalhl'
Gl5a {EU)} .nd ECM/PCIYI
ls DTC P1298 indicated)
Ch.ck lor tn oPan in tho wir'
(lGl linol:1. Turn the ignition and head'
liohts OFF2. D]""onn""t the ELD 3P con_
nector-3. Turn the ignition switch ON {ll)'
4. Measure voltage between body
ground and the ELD 3P connec
tor terminal No. '1.
R.oair ogan in tha wira Mw"n
ru". rs ltTEnrlton SP SelSOn
t?.5 A, fu!. in th. undcr-dr3h
tu3e/r.l!Y box .nd ELD.
Chcck lor tn oP.h in thc wire
{GND lincl:1. Turn the ignition switch and
headlights OFF.
2. Disconnect the ELD 3P con_
nector'3. Check for continuity between
body ground and the ELD 3P
connecto. terminal No 2
Raprir opcn in the wira bstwt€n
ELD conncctor lnd G/O2.
Ch.ck lor !n oplo in tha wirc IEL
lin.l:Check for continuity between the
ELD 3P connector terminal No 3
and ECM/PCM connector termi
nal D'16.
Rapaii opcn in the wira b€tw"n
ECM/FCM (I)161 .nd th. ELD'
Ch.d( fo. r m.llunction in thc ELD:
1. Reconnect the ELD 3P con'
2. Start th€ engine and allow it
to idle.3. Wh ile measuring voltage
beNveen ECM/PCM connector
terminals D16 and A9, turn
the headlights on {low).
Does the voltage droP?
Sub3titut. . known_good ECM/
PCM .nd rcch.ct. lt sYmptom/
indication goas away/ iapllc'
thc origin.l ECM/PCM
wire side of lemale termrnals
Wire side of Iemale terminals
t'a
)
1 1-181

PGM-FI System
Elestrical Load Detector (ELDI ('99 - 00 Models except D16y5 engine with M/Tl
The scan tool indicates Diagnostic Trouble code (DTCI Pl298: A high vottage problem in the Etectrical LoadDetector (ELD) circuit.
ELD 3P CONNECTOR (65/0
EL {GRN/REOI
Wire side of fernale terminals
ELD 3P CONNECTOR (CA54I
TIr l2l3l
I crvo
(o) (BrKr
Y
Wire side of lemale terminals
ECM/PCM CONNECTORSA (32P1
Wire side of lemaleEI- IGRN/RED)terminals
ECM/PCM CONNECTORS
A {32P)
Problem ve.itication:1. Do the ECN4/PCM Reset pro
cedure.2. Start the engine.3- Turn on headiights.Inte.mittent teilu.e, svstem is OKat this lime. Chock for Door con-nections or loose wires at Ci31{located under Jight side otdaihl, C354 (ELD) and ECM/PCM.
ls DTC P1298 indicated?
Check for an open in the wire{lG1 line}:1. Turn the ignition and head-lights OFF.2. Disconnect the ELD 3P con
3. Turn the ignition switch ON (ll).4. Measure voltage between bodyground and the ELD 3P connec-torterminalNo. 1.
Repair opon in tho wiro batwe€nNo. 15 ALTERNATOR Sp SENSOR{7.5 A} fuse in th6 undor-dashIuse/reley box and ELD.
ls there battery voltage?
Check for an open in the wiro{GND linel:1. Turn the ignition switch andheadlights OFF.2. Disconnect the ELD 3P connector.3. Check for continuity betweenbody ground and the ELD 3Pconnector terminal No. 2,
Repair open in the wire bstwoenELD connsctor and Gia02.
Check ,or an open in the wire IELlinel:1. Disconnect the ECM/PCM con-nector A (32P).2. Check for continuity betweenthe ELD 3P connector terminalNo. 3 and ECM/PCM connec-tor terminal A30.
Chock fo. a malfunction in the ELD:'1. Reconnect the ELD connectorand ECM/PCM connectorA (32P).
2. Stan the engine and allow itto idle.3. While measuring voltagebetween ECM/PCM connectorterminals A30 and B2O, turnthe headlighrs on ow).
ls there continuity?
Repsir op€n in the wire betweenELD connector and ECM/PCM.
Substitute a known-good ECM/PCM and recheck. lf symptom/indication goes away. replacelh6 original ECM/PCM.
Does the vokage drop?
Wire side of f€male terminals
11-182

ldle Control System
System Description
The idle speed ot the engine is controlled by the ldle Air Control (lAC) Valve.The valve changes the amount of air bypassing into the intake manifold in response to electric current controlled bv theECM/PCM. When the IAC Valve is activated, the valve opens lo maintain the proper idle speed.
D16Y5, D16Y8, Br6A2 engine (M/T):
(ROTARYItac vat-vEEI{GINEcooLAI{T
VARIOUSsEI{SORS
VARIOUSSENSORS
INTAKE MANIFOTDDl6Ys {CVTl, D16Y8 engine lA/T):
D16Y7 engine:
{ROTABY)
;iy--, - --- INTAKEMANIFOLD
11-190

1.After the engine starts, the lAc valve opens for a certain time. The amount of air is increased to raise the idle speed
about 150 - 300 rpm.
When the coolant temperature is tow, the IAC valve is opened to obtain the proper fast idle speed. The amount of
bypassed air is thus controlled in relation to the engine coolant temperature'
IOLE SPEED
lrpml
176
80
ENGI ECOOLANI TEMPERATURE
t" Fl
toc)
ll
't.Whentheid|espeedisoutofspeciiicationandthescantoo|doesnotindicateDiagnosticTroub|ecode(DTc)P0505
or P1508. check the following items:
. Adiust the idle speed {see page 11-220}
. Starter switch signal (see page 11-202)
. Air conditioning signal (see page l1-204)
. ALT FR signal (see Page 11-2081
' Brake switch signal (see page 11-210)
. PSP switch signal (excapt Canada model) (see page 11-212)
. A,/T gear position signal {see section 14, Dl6Y5 engine (CVT):
page 11-216). Clutch switch signal (D16Y5 engine with M/T) (see page 11-218)
. Hoses and connections
' IAC valve and its mounting O-rings
lf the above items are normal, substitute a known-good IAC valve and readjust the idle speed (see page 11-220)
|ftheid|espeedsti||cannotbeadjustedtospecification(andthescantoo|doesnotindicateDTcP0505orP]50S)
after IAC valve replacement. substitute a known-good ECM/PCM and recheck. lf symptom goes away, replace the
original ECM/PCM.

ldle Control System
ldle ControlSystem
lF0505 l Th" """n tool indicates Diagnostic Trouble Code (DTC) PO5O5: tdte controt system malfunction.
NOTE: lf DTC P1508 or P1509 is stored at the same time as DTC P0505, troubleshoot DTC p1508 or p1bog first. thenrecheck for DTC P0505.
Possible Cause
. IAC valve mechanical malfunction
. Throttle body clogged pon, improper adjustment. Intake manifold gasket leakage
. Intake air hose loose leakage
. Vacu um leak
. ECT sensor incorrect output
. Throttle Position sensor incorrect output*r
Troubleshooting Flowchart
The MIL has been reoorted on.DTC P0505 is stored.
Problem verification:1. Start the engine. Hold theeng;ne at 3,000 rpm with noload (jn Park or neutral) untilthe radiator fan comes on, then*r let it idle.t2. with rhe scan toot, ct'eit Ge l
Throttle position should beapprox. 10% with the throttle fully closed.E ngine coolant tempera-ture should be 194 205'F(90 96.Ci.lf they are not within thespec., repair the faulty sen
L._ _9oI9[cr]41 l3. Chec& the engine speed atidle with no-load cond;tionsiheadlights, blower fan, reardefogger, radiator fan, and airconditioner are not operating\see page l1-22O - 223).
Intermittent tailure, system is OKat this time.ls the idle speed OK?
ls it 550 rpm or less?
(To page 11,193)
*1r'96 models only
11-192
(To page ll-193)