1999 HONDA CIVIC PCM CONNECTOR A

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

tFo135l
iPol4tl
Heated Oxygen Sensor (HO2SI Heater
('96 - 98 Mbdels,'99 - 00 Dl6Y5 engine with M/Tl
*: p0141 (To page 11-158)**: D'16Y8 engane
The scan tool indicates Diagnostrc Trouble code (DTC) P0135: An electrical probl€m in the Primary Heated
Oxygen Sensor (Primary HOiS) (Sensor 1) Heater system (Except D16Y5 engine with M/T)'
The;can tool indicates Diagnostic Trouble code (DTC) P0141: A problem in the secondary Heated oxygen sensor
(secondarv HO2S) (Sensor 2) Heater circuit.
PRIMARY HO2S (Son.or 1l aP CONNECTOR
SECoNDARY HO2S tsensor 2l ilP CONNECTORT
Terminal side of male terminals
PRIMARY HOzS (SENSOR 1) 4P CONNECTOR ICl23I
SECONDARY HO2S ISENSOR 2) 4P CONNECTOR {C125I*
PO2SHIC, SO2SHTCIBLK/WHT)
Wire side of female terminals
SECONDARY HO2S ISENSOR 2),tP CONNECTOR 1C782)'*
so2sHTC{BLK/WHT)
Wire side oI female terminals
I(cont'd)
11-157
- The MIL h.s boen Jeponed on.- DTC P0135, and/or Polal .re
stoled.
Problem verificationl
1. Do the ECM/PCM Reset Pro-
ceduae,2. Start the enginelniermittent tailura, sYttam i! OK
at thi3 time, Chsck for Poor con'
neciion3 or loose wilG3 at
C131** (locat.d undo. right sido
ot dashl, C{32** (loc.ted under
middle ol dashl, C123 (PrimarY
HO2S. Sansor 1) C125 lc782l*r
{Socondery H02S, Sonsor 2l'
and EcM/PcM.Check for an open or 3hort in tho
HO25:1. Turn the ignition switch OFF.
2. Disconnect the HO2S (Primary
or Secondary*) (Sensor 1 or
Sensor 2) 4P connector'3. At the Ho2s side, measure
resistance between the HO2S
4P connector terminals No. 3
and No.4.
ls there 10 - 40 0?
Check for continuity between
body ground and the HO2S 4P
connector terminals No. 3 and
No.4 individually
Chock for an oPen ot short in tho
wire |PO2SHTC, SO2SHTC* linol:
1. Turn the ignition switch ON (ll).
2. Measure voltage between the
HO2S 4P connector terminalsNo.3 and No.4.
(To page 11'158)

PGM-FI System
a
a
Heated Oxygen Sensor (HO2S) Heater
('96 - 98 Models,'99 - 00 D16Y5 engine with M/T) (cont'dl
PRIMARY HO2S {SENSOR 1I 4P CONNECTOR{c1231SECONDARY HO2S {SENSOR 2} 4PcoNNECTOR 1C125)r
r-l --'1
ll i2l
f;T;ttcl|BLK/ &)YELI Y
Wire side of fomale lerminals
SECONDARY HO2SISENSOR 2) 4P CONNECTOR{c78ilf
IBLK/WHT)
Wire side of lemale terminals
(From page 11-157)
Wire sid€ ot temale terminals
SO2HTC(BLK/WHTI* PO2SHTC{BLK/WHTI
*: P0141*+: Dl6Y8 engine
11-158
(From page 11-157)
Check tor an op6n or 3hoft in thewire {lGl lin6):Measure voltage between theHO2S 4P connector terminals No.3(D16Y8 engine: No. 4) and bodyground.- Repair open or shon in thewire between Primary HO2Slson.or 1), {No. 15 ALTERNA-TOR SP SENSORI (7.5 Al fuseand Secondary HO2S, Sonsol2t,.- Replace the No. 15 ALTERNA-TOR SP SENSOR 17.5 A) tuse.Check for an open in the wireIPO2SHTC, SO2SHTC' linel:1. Turn the ignition switch OFF.2. Reconnect the HO2S 4P con-nector.3. Disconnect the ECM/PCM con-nector A (32P).
4. Turn the ignition switch ON (ll).
5. Measure voltage between theECM,/PCM connector terminals46 and 410 {A5 and A10)*.
Ropail opan in the wire b€twoenECM/PCM lA6, A5l* and HO2S{Primary, Secondary+1.
ls there 0.1 V or less?
Substitute a known-good ECM/PCM and recheck. ll symptom/indication goes awry, repbcetho origin.l ECM/PCM.
ECM/PCM CONNECTOR A I32P)
so2sHrc ItBLK/WH0.J
pozsxtc E/
IBI-K/WHTI ^,-----{v}-|.=,|I
PG1IBLK}3u I JsTgT roll12r3t5t6Ittar920z2l 2321
25272A2i3o
Check tor a short in the wire{PO2SHTC. SO2SHTC* line):'1. Turn the ignition switch OFF.2. Disconnect the ECM/PCM con-nector A (32P1.
3. Check for continuity betweenthe ECM/PCM connector termi-nal 46 (A5)* and body ground.
Repair short in thg wire betwe€nECM/PCM lA6, A5*l .nd HO2S(P.im.ry, Socondary*).
Substitute a known-good ECM/PCM and recheck. It symptom/indicetion goes away, rophcethe original ECM/PCM.

IHeated Oxygen Sensor (HO2S) Heater
i'ss - oo Mb-dels except D16Y5 engine with M/Tl
The scan toot indicates Diagnostic Trouble Code (DTC) P0135: An electrical problem in the Primary Heated
Oxygen Sensor (Primary ttOiS) (Sensor 1) Heater system {Except D15Y5 engine with M/T)'
The
-scan tool indicates Diagnostic Trouble Code (DTC) P0141; A problem in the Secondary Heated Oigen Sensor
(Secondarv HO2S) {Sensor 2) Heater circuit
Fo13sl
Fol11l
lntermiftent failuro, sYstom b OK
at thit limo. Ch6ck lor Poor oon'
nectiont or looso wita! at
C131'* {loc.tod und.t right ido
ol drshl, C432'* (located undel
middlo of dashl, C123 (PrimarY
HOzS, Sensor 1) C125 (Ct82lr'
(socondary HO2S, Sensor 2)t
.nd ECM/PCM.
PRIMAFY HO2S ls.n.or ll rrP CONNECTOR
SECOITIDARY HO2S (Srn.ol21 4P CONNECTOR'
Terminal side of male terminals
PRIMARY HO2S {SENSOR 1} ilP @NI{ECTOR lc123l
sEcoNDARY HO2S ISENSOR 2) aP @NNECTOR (C125)'
3l-, l-tl-t Fo2sHrc. so2sHrc
ver.t l ^-1 .'l {BLK/wHrl
11 '!'l-l
| --=- Iu----{v)'---..-'
Wire side of {emale terminals
SECO'TIDARY Ho2S (SENSOR 2,
4P CONNESTOR {C7&llt'
so2sHTc(BLKnflHTlIBLK/WHT)
(cont'd)
1 1-159
Wire side oI female terminals
r: p0141 {To page 11-160}**: D16Yg engine
- The MIL has been reponed on.- DTC P0135. and/or P0141 are
storod.
Problem vorification:1. Do the ECM/PCM Reset Pro-
cedute.2. Stan the englne.
Chock foi an open or short in the
HO25:1. Turn the ignition switch OFF
2. Disconnect the HO2S (Primary
or Secondary*) lSensor 1 or
Sensor 2) 4P connector'
3. At the H02S side, measure
resistance between the HO2S
4P connector terminals No. 3
and No.4.
ls there 10 - 40 n?
Check for continuity between
body ground and the HO2S 4P
connector terminals No. 3 and
No.4 individuallY.
Check for an opon or short in lho
wire (PO2SHTC, SO2SHTC+ line):'1. Turn the ignition switch ON (ll).
2. Measure voltage between the
H02S 4P connector termlnalsNo.3 and No.4.
{To page 11-160}

PGM-FI System
Heated Oxygen Sensor (HO2S) Heater
('99 - 00 Models except D16Y5 engine with M/T)
(From page 11-159)
Substitute a known-good ECM/PCM and recheck. lf symptom/indication goes away, replacethe origin.l ECM/PCM.
(cont'dl
PRIMARY HO2S ISENSOR 1I 4P CONNECTOB{c123)SECONDANY HO2S ISENSOR 2} 4PcoNNECTOR (C125)*
-r--r ,
lr zl
-f-13 4llc'l L--r-J-r
relxr p1YELI Y
Wire side of temale terminals
SECONDARY HO2S(SENSOR 21 4P CONNECTOR{c782}rr
IG1 IBLK/WHT)
NO
Wire side of female telminals
ECM/PCM CONNECTORS
Wire side of female terminals
ECM/FCM CONNECTORS
*: P0141**: Dl6Y8 engine
1 1-1 60
Check for an open in the wires{lGl* line}iMeasure voltage between the primary HO2S 4P connector terminalNo. 3 (D16Y8 engine: No. 4) andbody ground.- Repeir open or shon in thewire between Primary HO2Slsensor 1), {No. 15 ALTERNA-TOR SP SENSOR) (7.5 A) fus€and Secondary HO2S, Sensor2t,.- ReDlace the No. 15 ALTERNA-TOR SP SENSOR {7.5 A tuse.
ls there battery voltage?
Check ,or an open in the wires(PO2SHTC, SO2SHTC' linel:1. Turn the ignition switch OFF.2. Reconnect the HO2S 4P con-nector,3. Disconnect the ECN4/PCM connector C (31Pi (ECM/PCM con-nector A (32P))i.
4. Turn the ignition switch ON (lli.
5. Measure voltage between theECM/PCM connector terminals82 and Cl 182 and AB)*.
Reprir open in the wirc betwo€nECM/PCM (Cl, A8i) and HO2S(Primary, Secondary+).
ls there 0.1 V or less?
(From page 11 l59i
Check tor a short in the wiresIPO2SHTC, SO2SHTC* linel:1. Turn the ignition switch OFF.2. Disconnect the ECM/PCM con-nector C (31Pi (ECM/PCM connector A (32P)i*.
3. Check tor continuity betweenthe ECM/PCM connector terminal C1 {A8)* and body ground.
Repai. short in the wire b€tweenECM/PCM lcl, A8.l and HO2S(Pdmery, Secondary*1.
Substitute a known-good ECM/PCM end recheck. lf symptom/indication goes away, replacethe o.iginal ECM/PCM.
Wire side of female terminals

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