1996 HONDA CIVIC out

Check the ECM input vottage {lP-/
VS- lino):1. Turn the ignition switch OFF.
2 Turn the ignition switch ON (ll)
3. Measure voltage between
ECM connector terminals C24
Ch.ck the ECM:
1. Turn the ignition switch OFF
2. Disconndct ECM connector C
{31P){rom the ECM.
3. Check lor continuity between
body ground and ECM con
nector terminal C24
ls there more than 0.5 V?
- Repair open in the wire
betw€en ECM {C2{l and Pri-
ma.y HO2S {S€nsor 1 l.- Substitute a known-good ECM
and recheck. It symptom/indi
cation goes away. replace the
odginal ECM.
Check to. r short in the wi.e {lP-/
VS- lin6l:1. Disconnect the 8P connector
from the Primary HO2S lsen-
sor 1).2. Check tor continuity between
body ground and ECM connec-
tor terminal C24
Ropair short in the wire bstween
the Primary HO2S lsensor 1) and
ECM (C24).
Check the ECM output voltage
{VS+ linel:N4easure voltage between ECM
connectorterminals C25 and D11.
Check for a short in the wire (VS+
line):1. Turn the ignition switch OFF.
2. Disconnect ECM connector C
{31P) Irom the ECM.
3. Check {or continuity between
body ground and ECM con
nector terminal C25.
ls there mote than 0.5 V?
ECM CONNECTORS
lFrom page'11-146)c (31PlD {15P)
tP-/vs- tREolfemale termrnals
sG2(GRN/BLKI
(cont'd)
11-147
I23a68910
111213la15t6'171622
232a25272a2930
O rP-/vs-:Z taeot
,l23a55I910
1112131a151617t822
232125212AE30
0) {REDr
23a518910
l11213ta'15't6171822
2321E272A2930
[]) vs*I rwsrt
(To page 11- 148)(To page 11 148)

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

Secondary Heated Oxygen Sensor {secondary HO2S) (Sensor 2l
*'t : D16Y8 engine*2:'99 - O0 m;dels except D16Y5 engine with M//T
The scan tool indicates Diagnostic Trouble Code (DTC) P0137: A low voltage problem in the Secondary Heated
Oxygen Sensor (Secondary HO2S) (Sensor 2) circuit'
SECONDARY HO2S ls.n.ot 2),rP CONNECTOR (C125, C782')
Wire side oI temale terminals
(cont'd)
1 1-153
- Tho MIL has been reported on- DTC P0137 is stored.
Problem verification:1. Do the ECM/PCM Reset Pro
cedure.2. Start the engine. Hold the
engine at 3,000 rpm wlth no
load (in Park or neutral) until
the radiator fan comes on
3. With the scan tool, check the
Secondary HO2S (Sensor 2)
output voltage at 3,000 rPm
lntermittent frilure, sYdem is OK
at this tim6. Check for Poor con'
nections or loolo wir.3 at C131t(locatod undor right.ido of desh)'
C432. {located under middle of
dashl, cl25 lc782lr {SecondaryHO2S) tsensor 2l .nd ECM/PCM.
Does the voltage staY at 0.3 V
or less?
Ch6ck tot a sho.t in the S€condery
HO23:'1. Turn the ignition switch OFF.
2, Disconnect the SecondarY
HO2S lSensor 2)4P connector.
3. Start the engine.
4. Check the SecondarY HO2S
lsensor 2) output with the scan
tool,
Check tor a short in the wire
{SHO2S linel:1. Turn the ignition switch OFF.
2. Discon n ect tho EcM/PCM
connector D {16P) {A (32P))*'
3. Check for continuity between
the SecondarY H02S (Sensor
2) 4P connector terminal No 1
and body ground.
R€pair short in tho wire bstwoen
ECM/PCM lD14 (A231*'| and
Secondarv HOzS (Sensor 2).
Substitute a known-good ECM/
PCM and recheck lf 3ymptom/
indicalion go€s awaY, tePltco
the oiigin.l ECM/PCM.

PGM-FI System
I
a
a
9ggoqOfry Heated Oxygen Sensor (Secondary HO2S) {sensor 2l('96 - 98 Models; '99 - 00 D16YS engine with M/Tl
The scan tool indicates Diagnostic Trouble Code (DTC) PO'138: A high voltag€ problem in the Secondary HeatedOxygen Sensor (Secondary HO2SI (sensor 2) circuit.
SECONDARY HO2S ls.nsor 2l4P CONNECTOR C125 tc782t*
JUMPER WIRE
sHo2sIWHT/RED}
sHo2sG(RED/YEL)(GRN/WHT)*(GRN/BLK)*'
Wire side of female terminals
ECM/FCM CONN€CTOR D Il6PI
sH()2sG{YEL/RED){GRN/BLK}'
JUMPER WINE
Wire side of female terminals
'i D16Yg engine*1i Dl6Y5 engine
- Ths MIL ha3 bcen r6port.d on.- DTC m138 i. 3tored.
Problem vorilication: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 radiatorfan comes on.3. With the scan tool, ch€cktheSecondary HO2S {Sensor 2)outputvoltageat 3,000rpm.
Into.mittant failurc, sy3tem b OKrt thi3 tims. Ch6ck tor poor con-n6clionr or loo3€ wiroa at C13'l*(locat d und6r right lido of dr'h),C/€2r (loc.tod und€r middle old.rhl, C125 {C782lr (Socond.ryHO2S S6n3or 2) .nd ECM/PCM.
Chcd( for rn open in the Socond!ryf|o2s:1. Turn the ignition switch OFF.2. Disconnect the SecondaryHO2S (Sensor 2) 4P connector.3. Connect the Secondary HO2S(Sensor 2) 4P connector ter-minals No. 1 and No.2 with aJUmper wire.4. Tu.n the ignition switch ON (ll).5. Chock the Secondary HO2S(Sensor 2) output vollage withthe scan tool.
ls there 0.6 V or more?
Check tor an open in the wiro(SHO2S lin6l:1. Turn th6 ignition switch OFF.2. Connect ECM/PCM connectorterminals D14 and D13 with ajumper wire.3. Turn the ignition switch ON {ll}.4. Check the Secondary HO2S(Sensor 2) oltput voltagewith the scan tool.
Rapair op.n in the wiio botw.onECM/PCM lD13 and/or Dlal andS.cond.ry HO2S ls€nsor 21.
ls thore 0.6 V or more?
Subslituto a known-good ECM/PCM .nd rccheck. lt symptom/indication goe! rway, replacethe original ECM/PCM.
11-154

Secondary Heated Oxygen Sensor (SecondarytlO2S) (Sensor 2l
('99 - 00 lilodels except DtGYS engine with M/T)
The scan tool indicates Diagnostic Trouble code (DTC) P0138: A high voltage problem in the secondary Heated
Oxygen Sensor (Secondary H02S) (Sensor 2) circuit.
SECONDARY HO2S {S€nsot 2}
4P CONNECTOR Cl25 lc782l'
JUMPER WIRE
Ir
sH02s(WHT/RED)sG2{GRN/BLKI
Wire side of female termanals
ECM/PCM CONNECTORS
A (32P1
Wire side ot female termlnals
gs92g 111yp17p5py | .lutuPea wtne
- The MIL has beon reportod on.- DTC m138 is.tored.
Ploblem vorification:1. Do the ECM/PCN4 Reset Pro-
cedure.2. Start the engine Hold the
engine at 3,000 rpm with no
load (in Park or neutral) until
the radiator{an comes on
3. Check the SecondarY H02S(Sensor 2) output voltage at
3,000 rpm with the scan tool
lntormittont failuio, sYstom b OK
st thir timo. Check for Poor con_
nections ot loo39 wiJo3 af Cl3lr(located under right ride ot desh),
C432' (locatod undot middle of
dashl, Cl25 {C782lr (Secondaiy
HO2S Son3or 2l and ECM/PCM.
Does the voltage stay at 0 6 V
or more?
Ct€d( tor an opan in the Secondary
l|o2s:1. Turn the ignition switch OFF
2. Disconnect the SecondarY
HO2S (Sensor 2) 4P connector.
3. Connect the Secondary HO2S(Sensor 2) 4P conneclor ter_
minals No. 1 and No.2 with a
iumper wire.4. Turn the ignition switch ON (ll)
5. Check the SecondarY HO2S
lSensor 2) outptlt voltage with
the scan tool,
lsthere 0.6 V or more?
Check lor an open in the wiro(SHO2S line):1. Turn the ignition switch OFF.
2. Connect ECM/PCM connector
terminals A23 and C18 with ajumper wrre,
3. Turn the ignition switch ON (ll).
4. Check the SecondarY HO2S
{Sensor 2) outPut vo ltage
with the scan tool.
Repair opon in tho wire betwecn
ECM/PCM (A23) and SocondarY
HO2S {Sansor 2).ls there 0.6 V or more?
Substitut€ a known'good ECM/
PCM and recheck. It symptom/indication goes awey, JePlaco
the otiginel ECM/PCM
*i 016Y8 engine1 1-155

PGM-FI System
Secondary Heated Oxygen Sensor (Secondary HO2S) {sensor 2l
[FO13a]l The scan tool indic€tes Diagnostic Trouble Code {DTC) P0139: A slow response probtem in the Secondary Heated- Uxygen Sensor (HOzS) (Sensor 2) circuit.
1 1-156
- The MIL has been reported on.- DTC P0139 is stored.
Problem verification:1. Do the ECM/PCM Reset Pro-
2. Start the engine. Hold theengine at 3,000 rpm with noload {in Park or neutral) untilthe radiator fan comes on.3. With the scan tool, check theSecondary HO2S (Sensor 2)output at 3,000 rpm.
Intermiftent failure, system i! OKat this tims. Check for pool con-nections or loos6 wiles at C131.{located undor ght lide of dash),C432' (locrted under middle otd.shl Cl25 (C782lr (SocondaryHO2S) (Sonsor 2) and ECM/FCM.
Does the voltage stay within0.3 - 0.6 V for two minutes?
*: D16Y8 engine

t
Troubleshooting Flowchart
'l
NO
a-,-:- -
YES
- The MIL ha3 b€on rePorled on.- DTC P0171 a^dlot P0172 arc
stored,
is the fuel pressure OK?
Check the fuel pt€ssure regulator
and fusl re{urn pipe.ls the fuel pressure too high
ortoo low?
Check the Primary HO2S:
1. Start the engine. Hold the
engine at 3,000 rpm with no
Ioad (in Park or neutral) until
the radiator Ian comes on
2. Check the Primary HO2S(Sensor 1) output with the
scan tool,
Check the tu6l pump. fuel leedpipe, fu€l fiher, and Iuel Pressureregulator.
Does it stay at less than 0.3 V
or more than 0.6 V?
Check lor a sticking or leaking
EVAP purge control solenoid
With a vacuum PumP, aPPIY vacu-
um to the EVAP purge control
solenoid valve from the intake
manifold side.
Does it hold vacuum?
Check the MAP sensor outputr
1. Turn the ignition switch ON (ll)
2. Check the MAP with the scan
tool.
Check th6 response of the MAP
sensoa:1. Start the engine.2. Check the MAP with the scan
tool.
ls a MAP of 40.0 kPa 1300 mmHg,12.0 inHg) or less indicated within
one second after starting the
engine?
- Check th€ valve cloarance.- Check the EGR rystem lD16Y5enginel.- lf they are OK, r€place the tueliniocto]3.
1 1-165

I
Misfire Detected in One Cylinder
P0301 | The scan tool indicates Diagnostic Trouble Code (DTC) P0301: Cylinder 1 misfire detected.
[F03O2l 16"""untool indicates Diagnostic Trouble code (DTc) P0302: Cylinder2 misfire detected.
[FO3Ofl 16" ".un toot indicates Diagnostic Troubte Code (DTC) P0303; Cylinder 3 misfire detected.
I P0304 I ths..rr tool indicates Diagnostic Trouble Code (DTC) PO3O4: Cylinder 4 misfire detected.
D€scription
lMisfire detection is accomplished by monitoring the crankshaft speed with the crankshaft speed fluctuation (CKF) sensor
which is attached to the crankshaft,
lf misfiring strong enough to damage the catalyst is detected, the MIL will blink during the time of its occurrence, and DTC
PO3O1, P0302, PO3O3 or P0304 will be stored. Then, after the misfire has ceased, the MIL will come on.
lf misfiring that increases emissions is detected during two consecutive driving cyclss, the MIL will come on, and DTC
P0301, P0302, P0303 or P0304 will be stored.
NOTE: lf some of the DTCS listed below are stored at the same time as a misfire DTC, troubleshoot those DTCS first, then
recheck for the misfire DTC.
PO106*1, P0107, P0108. P1128*3'*5, P1129*3'*5: MAP sensor
P0131, P0132: HO2S
P0171, P0172iFuel suppiy system
P0335, P0336: CKF sensor
P0401. P1491, P1498: EGR system
P0441: EVAP system Insufficient purge flow*6
Pl359. P1361. Pl362: TDC sensor
P1381. Pl382: CYP sensor*o: '96 models*6: '96 D16Y5 engine,'96 D16Y/ engine,'96 D16Y8 engine {sedan),'97 D16Y5 engine,'97 D16\4, engine (coupe: KA,
KC models, sedan KA. KC, KL (DX) models, hatchback:all models),'97 D16Y8 engine (sedan: KA, KC models)
Possible Cause
. Fuel injector clogging, fuel leakage, air leakage
. Fuel injector circuit open or shorted
. Spark plug carbon deposits, fouling, malfunction
. lgnition wires open. leaking
. Distributor malfunction
. ComDression low
. Valve clearance out of spec
. VTEC system malfunction (D16Y5, D16Y8. 81642 engine)
. HO2S
. HO2S circuit
(cont'd)
11-167
r'a