idle HONDA CIVIC 1996 6.G Service Manual

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

Knock sensor (Ks) r99 - 00 D16Y5 engine with cw, '99 - 00 D16Y8 engine and
816A2 engine
The scan tool indicates Diagnostic Trouble Code (DTC) P0325: A malfunction in the circuit of the Knock Sensor
{KS}.
OIAPHRAGM
ECM/PCM CONNECTOR C (31P)
KS 2P CONNECTOR (C1371
KS
Wire side of female terminals
t
The MIL has been reported on.
DTC m325 is stored
Problem verification:1. Do the ECM/PCM Reset Pro
cedure,2. Start the engine Hold the
engine at 3,000 rpm with no
load (in Park or neutral) until
the radiator fan comes on,
then let it idle.
3. Hold the engine at 3.000 -
4,000 rpm for at least 60 sec'
onds.
lntermittent failure, system is OK
at thi3 time lt€3t drive maY b€
nocessaryl.Chsck tor poor connections or
loose wiros at C137 {knock sen'
sor {KSll and ECM/PCM.
ls DTC P0325 indicated?
Ch€ck for a short in tho wire (KS
linel:1. Turn the ignition switch OFF.
2, Disconnect the knock sensor
1P connector.3. Check for continuity between
ECM/PCM connector termi_
nals C3 and body ground.
Repri. short in the wiro bqtwecnECM/PCM lc3l and knock 3ensor.ls there continuity?
Check for an open in lhe wire
{KS linc):Check for continuity between
ECM/PCM connector terminal C3
and knock sensor connector ter-
minal No. 1.
Replir open in the wire bdtweon
ECM/PCM {Ctl and knock sensor'
SubstitLrte a known'good knock
sensor and recheck,
Replace tho otiginal knock sensor.
substitute a known-good ECM/PCM and recheck. ll symptom/indication goes awaY, rePl6co
tha o.iginal ECM/PCM.
Wire side of female terminals
ECM/PCM CONNECTOR
11-171

PGM-FI System
Barometric Pressure (BAROI Sensor
The scan tool indicates Diagnostic Trouble code (DTC) Pi106: A range/performance problem in the BaromerrrcPressure (BARO) Sensor circuit.
The scan tool indicates Diagnostic Trouble code (DTc) P1107: A low voltage probtem in the Baro sensor circurr.
The scan tool indicates Diagnostic Troubre code {DTC) p1108: A high vortage probrem in the Baro sensorcircuit.
fF1lot
tPlloal
The MIL ha3 been r€Dortsd on.DTC Pl106 is stored.
Problem verification:1. Do the ECM/PCM reset pro-cedure,2. Start the engine. Hold theengine at 3,000 rpm with noload (in Park or neutral) untilthe radiator fan comes on, thenlet it idle.3. Connect the SCS service connector.4. Test drive with the A/T in Eposition, M/T in 4th gear.5. Accelerate for five secondsusing wide open throttle.
Intormittont tailure, system is OKat this time.ls DTC P1106 indicated?
Substitut€ e known-good ECM/PCM and recheck. ll symptom/indication goes .way, .oplsce theo.iginal ECM/PCM.
The MIL has been .oported on.DTC P'l107 o. Pl108 is stored.
P.oblem veritication:1. Do the ECM/PClvl Reset pro
cedure,2. Turn the ignition switch ON (ll).
Intormittent frilure, syitem i3 OKat this time.ls DTC P1 107 or Pl108 indicated?
Substitute a known-good ECM/PCM and rechock. It symptom/indication goes away, .6placethe original ECM/PCM.
11-178

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)

I
L
1D16Y5, D16Y8 engine with M/T 81642 engine)I
D16Y7 engine:
{From page 11-192)
Check the IAC valve:Disconnect the 3P connector from
the IAC valve.
Check the IAC valve:Disconnect the 2P connectorfrom the IAC valve.
Does the engine speed drop or
the engine stall?
Adiust the {base} idle speod (see
page 11-220 - 2231.It it's impos-
aible, clean the ports in lhe throt'
tle bodv,
(From page 11-192i
Check Ior vacuum leaks:1. Turn the ignition switch OFF.2. Remove the intake air ductfrom the throttle body.
3. Start the engine and let it idle.
4. Put your finger on the lowerpon in the th.ottle body.
Ch€ck tor vecuum loaks, m.kesure the throttle valve is com_pletaly closed, end repair as nec-Does the engine speed droP?
Adiust the idle speed (see page
11-220 - 2231. lf it's impossible,
reolace the IAC velve.UPPERPORT
1 1-1 93

ldle Control System
ldle Air Control (lACl Vatve ('96 - 98 Dl6ys, Dl6yB engine with M/Tl
The scan tool indicates Diagnostic Trouble Code (DTC) P1508: A problem in the ldle Air Controt flAC) varvecircuit.
The IAC Valve changes the amount of air bypassing the throttle body in response to a current signal from the ECM inorder to maintain the proper idle speed.
IAC VALVE 2P CONNECTOR ICl3A)
,flrcerh-:J iYEL/BLKI
!.__-,/ -lt(v)
-T-=
Wire side of female terminals
tAcv(BLK/
ELUI
ECM CONNECTOR A I32PI
Wire side oI lemal€ terminals
VALVE
6a10ll12t3r5t6l7t8t920232a
t*25&a2A3o
The MIL hss b€on repo.ted on.DTC P'l508 i. itorod.
Problem vorification:1. Do the ECM/PCM Reset Pro-cedure,Start the engine, and warm ituP to normal operating tem-perature.
Intormittont t!llur., sy.tcm b OKat thb tim6. Chsck fol poor con-ncctionr or loo3e wirot at C138(lAC valv.l.nd ECM.
ls DTC P1508 indicated?
Check for an opcn in the wiro(lGPl line):1. Turn the ignition switch OFF.2. Disconnect the IAC valve 2Pconnector.3. Turn the ignition switch ON (ll).
4. Measure vohage between bodyground and the IAC valve 2Pconnectorterminal No. 2.
R.prir opan in the wiro botwa.nIAC valv..nd PGM-FI main r.l.y.
Chock for an opon or sho in thewire (IACV linal:1. Turn the ignition switch OFFand reconnect the IAC valveconnector.2. Disconnect the ECM connectorA (32P).
3. Turn the ignit;on switch ON (ll).4. Measure voltage betweenbody ground and ECM con-nector terminal A12.
(To page 1l-195)
11-194