heater HONDA CIVIC 1996 6.G User Guide

tl
Engine Coolant Refilling and Bleeding
CAUTION: when pouring engine coolant, be sure to
shut the relay box lid and not to lst coolant spill on the
eleqtrical parts or the paint. lf any coolant spills, rinse it
off immediately.
1. Slide the heater temperature control lever to maxl-
mum heat. Make sure the engine and radiator are
cool to the touch.
Remove the radiator caP.
Loosen the drain plug, and drain the coolant'
Remove the drain bolt from the cylinder block'
D16Y5. D16Y7, Dl6Yg sngines:
DRAIN PLUG
0d
I ro
78 N.m {8.0 kgl m.58lbt'ft)
6.
1.
B1642 engin€:
WASHERReplace.
DRAIN BOLT78 N m (8 0 kgf m' 58lbfft)
Apply liquid gasket to the drain bolt threads, then
reinstall the bolt with a new washer and tighten 't
securely.
Tighten the radiator drain plug securely
Remove, drain and reinstall the reservoir' Fill the
tank halfway to the MAX mark with water, then up
to the MAX mark with antitreeze.
(cont'd)
10-7
MAX MARK

!
Fuel and Emrsslons
SoecialToofs .....,...."..,. 11-2
Component Locations
lndex ....................., ......... 11-3
Svstem Description
Vacuum Connections ................,,..,.. ......... 11-12
Electrical Connections ...............,.,.,... ....... 11-29
System Connectors ........,.,.,.......................... 1 1-51
Troubleshooting
Troubleshooting Procedures ................. .. 11-81
Engine Control Module/PowertrainControl Module TerminalAfiangement ....,.,..... 11-88
Diagnostic Trouble Code Chart .................,., 11.97
How to Read Flowcharts .,.......................... . 11-103
PGM-Fl System
System Description ...... 11-10,1
Troubleshooting Flowcharts
Engine Control Module/PowertrainContlol Module ........ 11-107
Manitold Absolute Pressure Sensor .....'. . ... 11-115
fntake Air Temperatuie Sensor ..... . . ., . 11'121
Engine Coolant Temperatuae Sensol ........., 11-128
Throttle Position Sensor ...................,........... 11-132
Primary Heated Orygen Sensor (Sensor 1l ... 11-139
Secondary Heated Oxygen Sensor(Sensor 21.................................................... 1 1-153
Heated Oxygen Sensor Heater ...................,. 11-157
Fuel Supply System ...... 11-164
Random Mislire ......., ..11-166
Misfire Detected in One Cylindsr ................. 11-167
Knock Sensor .,.,............ 11-170
CKP/TDC/CYP Sensor ................................... 11'172
Vehicle Speed Sensor ...........,......,...,.,........... 1t-176
Barometric Pressure Sensor ...............,......... I 1-178
Electrical Load Detector,.,,............................ 1 1-179
CKF Sensor .................... 11-183
ECM/PCM Internal Circuit ............................. I 1-188
A/T Signal {TMA/TMBI .................................. I 1-189
ldle Control System
System Doscriplion ............ 11-190
Troubleshooting Flowcharts
ldle Control System ...... 11-192
ldle Air Control Va1ve .................................... I 1-19i1
Starter Switch Signal .................................... 1 1'202
Air Conditioning Signal ................................. 11'201
Ahernator FR Signal .................................... . 1 1-208
BrakeSwitch Signal ..................................... f 1"210
Power Sleering Prossure Switch Signal ......11-212
A/T Gear Position Signal ............................... 11-216
Clutch Swiich Signal ................................-.... 11-214
ldte Speed Setting . .............11-220
Fuel Supply System
Fuel Lines .,...................,.,.,.,11-221
Fuef Tube/Ouick-Connect Fittings ..........,.,........ 11 -227
System Description ....'.... 11-230
Fuel Pressure .......,.,,........... 11-230
Fuef fniectors ......................11-232
Fu€f Pressure Regulator .....,.......................'...,. 11-231
Fuef Fifter ............................11-235
Fuel Pump .............'.......'.... 11-236
PGM-FI Main Relay .............11'237
Fuel Tank ................ ....,...'.'.' 11'211
Intake Air System
System Description ....-.-.....11-243
Air Cfeaner ...........,......."". .11-211
Throttle Cable .....................11-211
Throttfe Body ........ ..'... . . .,.11-211
Fuel Iniestion Air Control System ,.,.,....-........... 11-250
Emission Control System
System Description .-..........11-252
Taifpip€ Emission ...............11-252
Three Way Catafytic Convert€r ............,.,,.,.,.,.... 11 -252
Exhaust Gas Racirculaiion System ...,.,,,,.,.,.,.,,. 11'254
Positive Crankcas€ Ventilation System .... . . .. 11-266
Evaoorative Emission Controls ..................,,..,.,. 11 -267

Troubleshooting
E n gine/P_o,weft ra in Control Module Term inal Arra n gement('96 - 98 Models, '99 - 00 Dl6yS engine with M/T)
-
ECM/PCM CONNECTOR A I32PI
1INJ62INJ3INJ21
INJl567I
LG110PGll1
IGPl12
ACV
131115
PCS
16
FLR17acc18MIL19ALTC20
tcM22PG221IGP2272A25
VSV30
SLU
ECM/PCM CONNECTOR A (32P)
'2: A./T (D16Y7, 016Y8 engine)13: CvT (D16Y5 enoin€)',4: A/T and D16y7 engine*5: Except A/T and D16Y7 €nsine'6r A/T (D16Y8 ensine)'7 Cw 1D16Y5 eng,nel and D16y8 ensrne'"'3:Bi..I?'Jt;".'e'.!ti.?i?l'""."T8"_";btfr
"fl
1-88
Wire side of female terminals
NOTE:Standard battery voltage12ts
'10i i,4/T (D16V5 engine)r11 Ex.ept M/l (D16V5 enqinelr12: 016Y5, D16YB enqine
r15:'97 016Y7 engine lcoupe: KL modet, sedan: KL (LXl modet),'98 D16Y7 engine
1
1
Sign.l
YELlNJ4 (No.4 FUEL INJECIOB)D ves No 4 ruel injector.Wilh engine runninq: ddly coniroted2BLUlNJ3 lNo. 3 FUEL TNJECTOBJDrives No. 3 lue Inteclor.38EDINJ2 (NO, 2 FUEI INJECTON)Drives No. 2 iuel njector.88NlNJl (No. 1 FUEL INJECTOB)Dives No. 1 ruelinjector.
5SO2SIITC (SECONDAFY HEATEDOXYGEN SENSOF HEATEF CONTFOL)
Orives secondary heated oxyqen sensorWith ignilion switch ON (lll: batery vo lageWith f!llywarmed up engine runninq:dLtv controled
6BLXAVHTPO2SHTC (PRIMAFY HEATEOOXYGEN SENSOR HEATERCONTROL)
Drives prihary healed oxygen sensorWith ignition switch ON ltt):baneryvottasewlhrdllywdrmedupcngne,Lnnrrq dury,orl.otred
FED{ESOL (EGF CONTRO!SOIENOIO VALVE)Drives EGF conlrolsoleno d vatve.Wilh EGR operating during drving wiih fu|y warmedup engrne: duty controttedWilh EGF nol opefating:O VE.EGRWith EGF operating du.ing driv og wilh iuty warmedup en9ine: dutycont.olted.With EGR not ooeralino; o V8*r/GFN/YELWS (VTEC SOLENOTD VALVE)Drives VTEC solenoid va veWilh eng ne at ow engine speed:O VWirh engine at h gh enqine speedr banery vohaae9BflN/BLKLG1 (LOGIC GROUND)Gro!nd lorthe €CM/PCM conlrotc rcuit.Lesslhan 1.0 V at a ttimest0ALKPG1 IPOWEF GFOUND)Ground ior rhe ECM/PCM power.tcuf.11YEVBLKIGPT iPOWEF SOUFCE)Power source forthe Ec[,l/PcM conlroWilh ignition swirch ON (tt): battery voltageWith gntron switch OFF: 0 VBLVBLUIACV (IDLE AIN CONTROL VALVE)Wilh engine r!nn ng: dlty contro ed13,.o8NIACV N lIDLE AI8 CONTFOLVALVE NEGATIVE SIOE)Drivesthe IAC valve {negalive side).
BLVBLUIACV P (IDLE AI8 CQNTROLVALVE POSITIVE SIDE)Orives IAC vaive (posilive side).
FEO/YELPCS (EVAP PURGE CONTFOTSOIENOIOVALVE)Drives EVAP pu.ge controtsolenoid vatve.Wilh engioe running, engin€ cootani betow 154,F'68'Cr bancry vohaSe w'ln ens nc runn,.o. eng,rc
GRN/YELFL8 (FUEL PU[4P FELAY)Orives fuelpump relay.0 V {or two secor os ahe' tJ n ng 'onir or \wnch ON ,,,,,
I7BLI(REOACC (A,/C CLUTCH RELAY)Drives A/C clutch relay.Wirh compressor ONr0 VWilh compressof OFF:banery votrage18GFN/ONNMIL (I\,lALFUNCTION INDICATOFWith MIL lLrned ON: 0 VWith illl turned OFF: banery volaqe19',AITC {AITERNAIOR CONIROL)se.ds ahernator controt signat.Wirh fully warmed.up engine ru.ntng: battery votlas€During drivins wnh smatl eteclricat toad: O V
20YEVGRNICM (IGNI'TION CONTROLMOOU!E)with ignltlon swilch ON (tl):b6n€ry vohageWilh ensine runnins: aboul t0 V (depending on
22BRN/BLKLG2 (LOGIC GAOUND)Ground for the ECM,/PCM conrrot ci'cu LLess than 1.0 V at a tt mes23BLKPG2 iPOWEA GROUND)Gro!nd lor the ECM/PCM power circuir.24YEUBLKlGP2 (POW€R SOUSCE)Power sou.ce lor the ECM/PCl, conrrolWnh ignilion swilch ON {it):battery vohageWilh ignilion switch OFF:0 V25*6WHT/FEDVSEF IREFEfl ENCE VOLTAGE)Provrdes reference voIaOe to TCM.With ignition switch ON (tt):abour 5 VWth gnition swltch OFF: O V21'1GFNFANC {RAOIATOR FANCONTFOL)Drives radialof fan ielay.With radialor fan f!nn nqr O VWilh radiato.tan stopped: batteryBL!2WBS (EVAP BYPASSSOLENOIO VALVE]Orives EVAP bypass sotenotd va !e.With ignirion swrrch ON (tt):barery vo rase
LT GRNA/VHTVSV (EVAP CONTFOTCANISTEFVENT SHUT VAIVE)Drives EVAP conlfot canisrer venl shulwnh ignirion sw'tch ON lr|l barery volaqe
WHT/NEDSLU (INTEFLOCK CONTFOLUNIT)Detects intenock conlrotLn t signalWhh ignition switch ON (tt)and brake pedadepf essed: battery vollage

Diagnostic Trouble Code (DTCI Chart
connector is connecteda1: Dl6Y5 engine (CVT)*2: Except D16Y5 engine (M/T)*14:'97 model*15:'96 model*16: '98 model
(cont'd)
11-97
DTC
{MlL indication*lDelection liemProbable CausePage
Manifold Absolute
Pressure Circuit
Range/Performance Problem
. Vacuu m connection. MAP sensor11115
P0107 (3)
Manifold Absolute
Pressure Circuit
Low Input
Open or short in MAP sensor circuit
MAP sensor
ECMiPCM
TCM*1
11't1'l
P0108 (3)Manifold Absolute
Pressure Circuit
High Input
Open in MAP sensor circuit
MAP sensor
ECtvt/PCM
't 1 121
P0.111*14. *15 (10)
lntake Air Temperature
Circuit
Range/Performance Problem
. IAT sensor11-124
PO112 {10}
Intake Air
Temperature Circuit
Low Input
Short in IAT sensor circuit
IAT sensor
ECMiPCM
11-125
P0113 (10)lntake Air
Temperature Circuit
High Input
Open in IAT sensor circuit
IAT sensor
ECM/PCM
't1-126
P0116 (86)Engine Coolant
Temperature Circuit
Range/Performance Problem
. ECT sensor. Cooling system11-124
PO't't7 {6)
Engine Coolant
Temperature Circuit
Low Input
Short in ECT sensor circuit
ECT sensor
ECM/PCM
11-129
P0118 (6)Engine Coolant
Temperature Circuit
High lnput
Open in ECT sensor circuit
ECT sensor
ECM/PCM
11-130
?0122 t1l
Throttle Position
CircuitLow Input
Open or short in TP sensor circuit
TP sensorECM/PCM
TCM*1
11-132
P0123 (7)Throttle Position
Circuit
High Input
Open in TP sensor circuit
TP sensor
ECM/PClvl
11-136
P0131*' (1)
Primary Heated Oxygen Sensor
Circuit Low Voltage(Sensor 1)
Short in Primary HO2S (Sensorl ) circuit
Primary HO2S {Sensor 1)
Fuel supply system
ECM/PCM
1 1-139
P0132*' ('r)
Primary Heated Oxygen Sensor
Circuit High Voltage(Sensor 1)
Open in Primary HO2S {Sensor 1} circuit
Primary HO2S (Sensor 1)
ECM/PCM
1 1- 143
P0133*' (61)
Primary Heated Oxygen Sensor
Slow Response(Sensor 1)
. Primary HO2S (Sensorl). Exhaust system11-145
P0135*? (41)
Primary Heated Oxygen
Sensor Heater
Circuit Malfunction(Sensor 1)
. Open or short in Primary HO2S(Sensor 1) heater circuit. ECM11-151
*: The DTCS in parenthesis will be indicated by the blinking of the Malfunction Indicator Lamp (MlL) when the SCS service
! ta

Troubleshooting
DTClMlL indicationlDatection hsmProbablo CausePage
P0137(63)Secondary Heated Oxygen SensorCircuit Low Voltage(Sensor 2)
Short in Secondary HO2S lSensor 2) circuitSecondary H02S {Sensor 2)ECM/PCI\41 1-153
P0r38 {63)Secondary Heated Oxygen SensorCircuit High Voltage(Sensor 2)
Open in Secondary HO2S (Sensor 2) circuitSecondary HO2S (Sensor 2)EC[I/PCM11-154
P0'139 (63)Secondary Heated Orygen SensorSlow Response(Sensor 2)
Secondary H02S lSensor 2)1l-156
P0141 (65)
Secondary Heated Oxygen SensorHeaterCircuit Malfunction(Sensor 2)
. Open or short in Secondary HO2S (Sensor2) heater circuit. ECM/PCM11-157
P0171 (45)
System Too LeanFuel supply systemPrimary HO2S (Sensor 1)MAP sensorContaminated fuelValve clearanceExhaust leakage
11,164
P0172 (45)
System Too RichFuel supply systemPrimary HO2S (sensor l)MAP sensorContaminated fuelValve clearance
11-164
P0300*16' }l?
andsome ofPo3o1 /r'' \P0302 l72lP0303 l73lP0304 \7 4l
Random Misfirelgnition systemFuel supply systemMAP sensorEGR systemIAC valveContaminated fuelLack of fuel
r1-r66
P0301P0302P0303P0304
/rt\172ll73l\7 4l
- Cylinder 1- Cylinder 2- Cylinder 3- Cylinder 4Misfire Detected
Fuel InjectorFuel Injector circuitlgnition systemLow compressionValve clearance
11 167
P0325*3 (23)Knock Sensor (KS) CircuitMalfunctionOpen or short in Knock Sensor (KS) circuitKnock Sensor {KS)ECM/FCtvl11-170
P0335(4)Crankshaft PositionSensor CircuitMalfunction
Crankshaft Position SensorCrankshaft Position Sensor circuitECM/PCM11-172
P0336(4)Crankshaft PositionSensorRange/Performance
. Crankshaft Position Sensor. Timing belt skipped teeth11-172
P040'r*r (80)Exhaust GasRecirculationInsufficient Flow Detected
' EGR valve. EGR line
P0420(67)Catalyst SystemEfficiency BelowThreshold
. Th.ee Way Catalytic converter. Secondary HO2S11 253
Diagnostic Trouble Code (DTCI Chat (cont'dl
*3: D16Y5 engine (CVT), D16Y8 engine and B1642 engine*4: D'16Y5 engine*16: '98 model+17: '99 - 00 models
,Jla
1 1-98

Troubleshooting
Diagnostic Trouble Code (DTGI Chart (cont'dl
*7: D16YS engine (M/T)*8: D16Y5, D'16Y8 engine*9: USA model*14r'97 model*15r '96 model
DTC(MlL indicationlDetection lt6mProbablc CausePage
P1162+1 (48)Primary Heated Oxygen Sensor(Sensor 1) CircuitMalfunction
Open or short in Primarv HO2S (Sensor 1Primary H02S (Sensor 1)1 1- 146
P]163' (61)Primary Heated Oxygen Sensor(Sensor '1) CircuitSlow Response
. Primary HO2S (Sensor 1)
11-145
Pl164*r (61)Primary Heated Oxygen Sensor(Sensor l) Cjrcuit Range/Performance Problem
. Primary HO2S (Sensor 1)
1 1- 150
P1165*? (61)Primary Heated Oxygen Sensor(Sensor 1) Circuit Range/Performance Problem
. Primary HO2S (Sensor 1)
11-150
P1166' (41i
Primary Heated Oxygen Sensor(Sensor '1) Heater System ElectricalProblem
Open or short in Primary HO2S (Sensor 1)heater circuitPrimary HO2S (Sensor 1)ECM/PCM
1 1-'161
P1167*' (41)Primary Heated Oxygen SensorlSensor 1) Heater SystemMalfunction
Open in Primary HO2S (Sensor 1) VS+ circuitPrimary HO2S (Sensor 1) HeaterPrimarv HO2S {Sensor 1)1 1- 163
P1168*' (48)Primary Heated Oxygen Sensor(Sensor 1) LABEL Low Input
. Short in Primary HO2S (Sensor 1) LABELcircuit11-151
Pl169*? (48)
Primary Heated Oxygen Sensor(Sensor 1)IABEL High Input. Open in Primary HO2S (Sensor 1)IABELcircuit. Short in ground circuit11.152
P1259*3(221
WEC System MalfunctionWEC Solenoid ValveOpen or short in WEC SolenoidValve circu itVTEC Pressure SwitchOpen or short in VTEC Pressure SwitchcircuitECM,FCM
Section 6
P1297*s (20)Electrical LoadDetector CircuitLow Input
Electrical Load DetectorElectrical Load Detector circuitECM/PCM11-179
Pr298+' l20l
Electrical LoadDetector CircuitHigh Input
Electrical Load DetectorElectrical Load Detector circuitECM/PCM1 1-181
anosome ofP0301P0302P0303P0304
l71ll72ll73ll7 4l
Bandom Misfirelgnition systemFuel supply systemMAP sensorEGR systemIAC valveContaminated fuelLack ol fuel
11-166
1 1-100

PGM-FI System
System Description
CKP/TDC/CYP Sensor
MAP Sensor
IAT SensorTP SensorEGR Valve Lift Sensor*'Primary H02SSecondary HO2SVSSBARO SensorELD*'KS€Starter SignalALT FR SignalAir Conditioning SignalA/T Gear Position SignalBattery Voltage {lGN.1}Erake Switch SignalPSP Switch SignalFuel Tank Pressure Sensor*iVTEC Pressure Switch*5Clutch Switch Signal*6Countershaft Speed SensornBMainshaft Speed Sensorrs
-\
----t /
F;ilrr j"-----fi-tri-'r.;l
Fb"t."'i" d" c;;il
F,h"'c;;tr*".io";-l
@."r.l"sc;;ll
EaM/PcM B""k-p F"""till
r\
-:/
Fuel IniectorsPGM-Fl Main Belay {Fuel Pump)MILIAC Valve!y'C Compressor Clutch RelayRadiator Fan Relay*,Condenser Fan RelayALT*'lcMEVAP Purge Control Solenoid
Primary HO2S HeaterSecondary H02S HeaterEGR Control Solenoid Valve*rEGR valve*6EVAP Bypass Solenoid Valve*'EVAP Control Canister Vent Shut
VTEC Solenoid Valve*5DLCLock-up Control Solenoid Valve*aShift Control Solenoid Valve*3Linear Solenoid Valve*3
*1: Dl6Y5 engine*2: USA model*3: CW (D16Y5 ensine), D16Y8 engine and 81642 ensine*4: '96 D16Y8 engine lcoupe),'97 Dl6Y7 engine (coupe: KL model, sedan: KL (LX) model),'97 D16Y8 engine {coupe: all models, sedan: KLmodel),'98-all models,'99'all models,'00-all models+5: D16Y5, D16Y8,816A2 engine*6: M/T (D16Y5 enginei*7: CVT 1D'l6Y5 engine)+8: A/T (D16Y7, D16Y8 engine)*9: '96 D16Y5 engine,'96 D16Y7 engine,'96 Dl6Y8 engine (sedan),'97 D16Y5 engine,'97 Dl6Y7 engine (coupe: KA, KC models, sedan:KA, KC, KL (LX) models, hatchback: all models),'97 D16Y8 engine (sedan: KA, KC modelsi
PGM-FI Sy3lem
The PGM-Fl system on this model is a sequential multipon fuel injection system.
Fuel iniector Timing and Duration
The ECM/PCM contains memories for the basic discharge durations at various engine speeds and manifold air flow rates.
The basic discharge duration, after being read out from the memory. is further modified by signals sent from various sen-
sors to obtain the final discharge duration.
ldle Air Control
ldle Air Control Valve llAC Valve)
When the engine is cold. the A,/C compressor is on, the transmission is in gear, the brake pedal is depressed, the P/S load
is high, or the alternator is charging, the ECM/PCM controls current to the IAC Valve to maintain the correct idle speed.
lgnition Timing Control
. The ECM/PCM contains memories for basic ignition timing at various engine speeds and manifold air flow rates.
lgnition timing is also adjusted for engine coolant temperature.
. Aknockcontrol system was adopted which sets the ideal ignition timing for the octane rating ofthegasoline used.*3
Othgr Control Funqtions
1. Starting Control
When the engine is started, the ECM/PCM provides a rich mixture by increasing fuel injector duration.
2. Fuel Pump Control
. When the ignition switch is initially turned on, the ECM/PCM supplies ground to the PGM-Fl main relay that sup-plies current to the fuel pump for two seconds to pressurize the fuel system.. When the engine is running, the ECI\4PCM supplies ground to the PGM-FI majn relay that supplies current to the fuel
oumo.
. When the engine is not running and the ignition is on, the ECM/PCM cuts ground to the PGM-FI main relay which
cuts current to the fuel pump.
11-104
INPUTS
ENGINE CONTROL MODULE (ECMY
POWERTRAIN CONTROL MODULE (PCM) OUTPUTS

Primary Heated Oxygen Sensor {Primary HO2SI (Sensor 1)
t('96 - 98 Models except Dl6Y5 engine with M/Tl
The Heated Oxygen Sensor (HO2S) detects the oxygen content in the exhaust gas and signals the ECM/PCM. In operation,
the ECM/PCM receives the sjgnals from the sensor and varies the duration during which fuel is injected To stabilize the
sensor,s output, the sensor has an internal heater. The Primary HO2S (Sensor 1) is installed in the exhaust manifold.
HO2S:
VOLTAGE {VI
The scan tool indicates Diagnostic Trouble Code (DTC) P0131; A low voltage
Oxygen Sensor (H02S) (Sensor 1) circuit.
R|cH-AIR- - LEANFUELRANO
problem in the Primary Heated
SENSOR
ztRcoNlA
The MIL has be€n teported on.DTC P0131 is siorcd.
Problom verificalion: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,3. Test-drive with the A/T in Eposition (M/T in 4th gear)
4. Check the Primary HO2S(Sensor 1) output voltage with
the scan tool during accelera-
tion using wide open throttle.
lntcrmift€nt failura, 3Y3tem is OKat this tims. Check for Poor con-nections or loo3e wi.o3 at C123(Primlry HO2S, 3sn3or 1) and
ECM/PCM,
(To page 1I-140)
{cont'd)
1 1-139

Primary Heated Oxygen Sensor (Primary- Fjq?S) (Sensor 1l
('99 - 0b Models exiept D16Y5 engine with M/T)
TheHeatedoxygensensors(Ho2S)detecttheoxygencontentintheexhaustgasandsigna|stheEcM/PcM'|noperation,
the EcM/pcM receives the signars from the sensor and varies the duration during which fuel is injected. To stabilize the
sensor,soutput,thesensornasaninternaIheater.ThePrimaryHo2S(sensorl)isinsta|ledinexhaustmanifo|d(D16Y8.
81642 engine: exhaust PiPe A)
SENSORTERMINALSVOLTAG€ (VI
HEATERTERMINALS
The scan tool indicates Diagnostic Trouble Code (DTC) P0131: A low voltage
Oxygen Sensor (HO2S) (Sensor 1) circuit
RICH+ AIR- - LEANFUELRATIO
problem in the Primary Heated
HEATER
- The MIL has been t€Ported on.- DTC P013'l is stored.
Problem veritication:1. Do the ECM/PCM Reset Pro-
2. Start the engine. Hold the
engine at 3,000 rpm wrth no
load (in Park or neutral) until
the radiator fan comes on
3. Check the PrimarY HO2S
lSensor 1) output voltage wath
the scan tool during accelera
tion using wide open throttle
lntermittont f.ilure, 3ystem i3 OK
at thi3 time. Check tor Poor con'
nections or loose wires el C123
{Primary HO2S, Sensor 1) and
ECM/PCM.
Does the voltage stay at 0 5 v
or less?
Check the fuel pressLlre (see Page11,109).
(To page 11 142)(cont'd)
11-141

Primary Heated Oxygen Sensor (Primary HO2S) (Sensor 1l
The scan tool indicates Diagnostic Trouble Code (DTC) P0133: A slow response problem in the Primary Heated
Oxygen Sensor {Primary H02S) (Sensor 1) circuit.
The scan tool indicates Diagnostic Trouble code (DTC) Pl163: A slow response problem in the Primary Heated
Oxygen Sensor (Primary HO2S) (Sensor 1)circuit
Description
By controlling the airlfuel ratio with a Primary Ho2S {Sensor 1) and a secondary HO2S {Sensor 2), the deterioration of the
primary HO2S (Sensor 1) can be evaluated by its feedback period. when the feedback period of the Ho2s exceeds a cer-
tain value during stable driving conditions, the sensor will be judged as deteriorated
when deterioration has been detected during two consecutive trips. the MIL comes on and DTC P0133 or P1163* will be stored'
NOTE: tf DTC P0131, P0132 and/or P0135 are stored at the same time as DTC P0133, troubleshoot those DTCS first' then
troubleshoot DTC P0133. lf DTC Pl 162, P1168 and/or P1169 are stored at the same time as DTC P1163, troubleshoot those
DTCS first, then recheck for DTC Pl163.
Possible Cause
o Primary HO2S (Sensor 'l) Deterioration
o Primary HO2S Heater (Sensor 1)Deterioration
. Exhaust system leakage
Troublsshooting Flowchart
tFol3al
I P1163
- The MIL has been reported on- DTC P0133 and/or Pl163* is
stored,
Problem Verilication:1. Do the ECM/PCM Reset Pro
cedure-2. Connect the scan tool
3. Start the engine. Hold the
engine at 3,000 rpm with no
load (in Park or neutral) until
the radiator fan comes on
4. Connect the SCS service con-
nector.5. Test-drive u nder Iollowing
conditions.- 55 mph (88 km/h) steadyspeed- A/f in D position {M/T in
5th gear)
Until readiness code comes
lntermittent failure, 3Y3tem i3 OK
at thi3 time. Ch.ck lol Poor con-
ncctions or loosc wiros at C123
{C145)! lPrimary HO2S, Sensor 1l
and ECM/PCM.
Replace th6 Prim.ry HO2S (Sen'
sor 11.
*: P'l163 (D16Y5 engine with M/T)
11-145