1999 HONDA CIVIC engine

Heated Oxygen Sensor (HO2SI Heater (Dl6Y5 engine with M/Tl
The scan tool indicates Diagnostic Trouble Code (DTC) P1166: An electrical problem in the Primary Heated
Oxygen Sensor (Primary H02S) Heater system.
PRIMABY HO2S ISENSOR 1I 8P CONNECTOR
Terminal side ofmale terminals
I(cont'd)
11-161
- The MIL has been lePorted
- DTC Pl166 b stored.
Problem verilication:1. Do the ECM Reset Procedure.
2. Start the engine.
Intermitlent failura, sYstem b OK
at this time (te3t drive maY be
ngcessary). Check for poor con-
nections or loose wires between
C145 (Primary HO2S, Sen3or 1l
end ECM.
ls DTC P'l166 indicated?
Check the Primary HO2S (Sensot
1l resistence:1. Turn the ignition switch OFF
2. Disconnect the Primary HO2S(Sensor 1) 8P connector.
3. At the Primary HO2S (Sen
sor 1), measure resistance
between No. 1 and No. 2 ter_
Replace lhe Primery HO2S (Sen-
sor 11.ls there 2 13 O?
Check for a shorted PrimarY
HO2S lsensor 1):Check for continuity between
body ground and each terminal.
Check for a shorted PrimarY
HO2S {S€nsor 1l:
Check for continuity between ter'
minal No. 1 and terminals No.3,
4, 6, 7 and 8 individually.
ls there conlrnuily?
(To page 11'162)

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| ---

The scan tool indicates Diagnostic Trouble Code (DTC) Pl167: A system malfunction in the Primary Heated
Orygen Sensor {Primary HO2S) (Sensor 1) Heater circuit
PRIMABY HO2S ISENSOR 1} 8P CONNECTOR
tc145l
ECM CONNECTOR C (31P)
- The MIL has be€n reported on.- DTC Pl167 i3 3tored.
Problem Veritication:1. Do the ECM Reset Procedure.
2. Start the engine. Hold the
engine at 3,000 mm with no
load (transmission in neutral)
until the radiator fan comes
on.Intormittont failure, system i3 OK
at thia time. Chock for Poor con_
noction3 or looso wilgt ai Cl45(Primary HO2S, Son3or 1l andECM.
ls DTC1167 indicated?
Check lor sn open in the wire(VS+ linel:1. Turn the ignition switch OFF
2. Disconnect the Primary HO2S
{Sensor 1) 8P connector.
3. Turn the ignition switch ON (ll).
4. Measure voltage betwe€n thePrimary HO2S (Sensor '1) 8P
connector terminal No 6 and
body ground.
Ch.ck the ECM:Measure voltage between the
ECM connector terminsl C25 and
body ground.
ls there more than 5 V?
Repair opon in the wite ECM (C25)
and P m.ry HO2S (S€n3or 11.ls there more than 5 V?
Replaco the Primary HO2S (Son-
sor 11.Substitute ! known-good ECM
and r6check. lf symptom/indica-tion gos6 away, r.place tho origi'
nd ECM,
,l23458910
111213t415161718
a2125a30
VS+{WHTIWire side of femaleterminals
1 1-163

PGM-FI System
Fuel Supply System
D017-il Th""""ntool indicates Diagnostic Troubte Code {DTC) p0171;Thefuet system istoo lean.
1P0172 | fne scan tool indicates Dlagnostic Trouble Code (DTC) P0172:Thefuel system istoo rich.
Description
By monitoring the Long Term Fuel Trim, long term malfunctions in the fuel system will be detected.lf a malfunction has been detected during two consecutive trips, the MIL will come on and DTC P0171 and/or P0172 will bestored.
NOTE: lf some of the DTCS listed below are stored at the same time as DTC P0171 andlot P0172, ltouhleshoot those DTCSfirst. then recheck for DTC P0l7l andlot P0172.
P0106-8, P1128*3. *5, P1129*3 *5 MAP Sensor
P0135; Primary HO2S Heater
P0137. P0138: Secondary HO2S
P0'141: Secondary HO2S Heater
P0401: EGR Flow Insufficient*1
P0441: EVAP System Insufficient Purge Flow*6
P1259: VTEC System*,
P1491:EGR Valve Lift Insufficient*r
P1498: EGR Valve Lift Sensor Hjgh Voltage*r
*r: D16Y5 engines*': Dl6Y5, D16Y8, 81642 engine*3: '97 models*a:'96 modelsf 5: '98 - 00 models*6: '96 D16Y5 engine,'96 D16Y7 engine,'96 D16Y8 engine (sedan),'97 D16y5 engine,,97 D16y7 engine (coupe: KA, KC mo+els, sedan KA. KC, KL (DX) models. hatchback; all models),'97 D16Y8 engine (sedan: KA, KC models)
Possible Cause
DTC P0'171
loo lean
DTC P0172
too rach
Fuel Pump insuff icient f lovpressure
Fuel Feed Line clogged, leaking
Fuel Pressure Regulator stuck open
Fuel Filter clogged
Fuel Injector clogged, air inclusion
Gasoline doesn't meet Owner's Manual spec.
Primary HO2S (Sensor 1) deteriorated
MAP Sensor range/performance*.
EGR System malfunction (too much flow)*1
Valve Clearance
Exhaust leak
Fuel Pressure Regulator clogged, stuck closed
Fuel Return Pipe clogged
Fuel Injector leaking
Gasoline doesn't meet Owner's Manual spec.Primary HO2S (Sensor 1) deteriorated
MAP Sensor range/performance*a
EGR System insufficient flow*1
EVAP Purge Control Solenoid Valve leaking, stuck opened
Valve Clearance
11-164

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

PGM-FI System
Random Misfire
lFoioo l*u o, [FTioo l*' *' and
The scan tool indicates Diagnostic Trouble Code (DTC)
P0300*5 or P1300*3 *1 and some of P0301 - P0304:Random misfire.Description
Misfire detection is accomplished by monitoring the crankshaft speed with the crankshaft speed fluctuation (CKF) sensorwhich 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 DTCP0300*5 or P1300*3'*' and some of DTCs P0301 through P0304 will be stored. Then, after misfire has ceased, the MIL willcome on.
lf misfiring that increases emissions is detected during two consecutive driving cycles, the MIL will come on, and DTCP0300*5 or P1300*3 *a and some of DTCS P0301 through 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, thenrecheck for the misfire DTC.
P0106*4. P0107. P0108, P1128*3 *5, Pl129*3 *5; MAP sensorP0131. P0132: HO2S
P0171, P0112i Fuel metering
P0401, P 1491, P1498: EGR svstem*1P0505: ldle Control SystemP1253: VTEC System*,P1361, P1362: TDC sensorP1381, Pl382: CYP sensorP1508: IAC valve
Possible Cause. Fuel pump insufficient fuel pressure, amount of flow. Fuel line clogging, blockage, leakage. Fuel filter clogging. Fuel pressure regulator stuck open. EGR system malfunction*1. Distributormalfunction. lgnition coil wire open. leakage *l: D16Y5 engine. lgnition control module malfunction *2: D16Y5, D16Y8, Bt6A2 engine. MAP sensor range/performance, poor response*r *3: '97 models. Valves carbon deposit *4;'96 models. Compression low *5: '98 - 00 models. IAC valve malfunctionr.. VTEC system malfunction*,. Fuel does not meet Owner's Manual spec., lackoffuel. HO2S. HO2S circuit
Troubleshooting
By test-driving, determine the conditions during which misfire occurs, Depending on these conditions, test in the orderdescribed in the table below.
Possible
- --^ ---
rage
causeEGR*1
system
Crankshaft
position (CKP)
sensor
Fuel
pressure
Distributor and
lgnition wirestcMClearance
tAc
ValveMAP
sensor
section 611-230,
231section 23section 23section 611-19411
Only low rpm and
loado@@oo
Only accelerating@o@@
Only high rpm and
toaooo@
Not specificoo@
NOTE: lf misfire doesn't recur, some possible causes are fuel that doesn't meet owne/s manualspec, lack of fuel, carbon deposits on spark plug, etc.
1 1-1 66
I
P0304

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

PGM-FI System
Misfire in Detected One Gylinder (cont'dl
Troubleshootin g Flowchart
NOTE:. lf there is no treeze data of misfiring,just clear the DTC.. It there is no freeze data of misfiring,test drives under various conditions
- The MIL has been reoorted on.- DTC P0301. P0302. P0303, orP030il is indicated.
Check the fuel iniecto. lunction:Stan the engine, and listen for aclicking sound at the fuel injectorin the problem cylinder.
Check for an open or short in theharness between ECM/PCM andthe fuel iniector.
Repair open or short in the wir€.
Replace the fuel iniector.Sub3titute a known-goodECM/PCM and recheck. Itsymptom/indication goesaway, replace the original ECM/PCM.
Problem verification:1. After checking and recordingthe freeze data, do the ECM/PCM Reset Procedure.2. Exchange the spark plug fromthe problem cylinder with onefrom another cylinder,3. Connect the SCS service con'nector,4. Test-drive the vehicle severaltimes in the range ofthe free2edata.
(To page 11-169)
1 1-1 68