1996 HONDA CIVIC o2 sensor

PGM-FI System
Throttle Position (TPl Sensor ('99 - 00 Models except D16Y5 engine with M/T)
lTO12Z _TI scan tool indicates Diaqnosttc Trouble Code (DTC) P0122: A low voltage problem in the Throttle position- { | r, sensoa crrcurl.
The TP Sensor is a potantiometer. lt is connected to the throttle valve shaft. As the throttle position changes, the throttleposition sensor varies the voltage signal to the ECM/PCM.
ERUSHHOI.DENOUTPUT VOLTAGE (VIBRUSH
BESIS?OF
TERi'I AL
5
4
3
2
1
o
INNERBUS}IINGTHROTTLEOPE II{G
FULLTHROTTLE
TP SENSOR 3P CONNECTOR {Cl1OI
sG2IGRN/8LKIvcc2(YEUBLUI
Wire side of temale terminals
ECM/PCM OONNECTOR C 131P)
Ch.Gk for rn opan or 3hort in TP36nlot:1. Turn the ignition switch OFF.2, At the sensor side, moasureresistance between the TPsensor 3P connector terminalsNo. 1 and No. 2 with th€ throt,tle fully closed.
(To page 11-135)
- Th. MIL har boon.6portcd on.- DTC P0122 b siored.
Problem verification:1. Start the engine, Hold theengine at 3,000 rpm with noload (in Park or neutral) untilthe radiator fan comes on.then turn the ignition switchOFF,2. Turn the ignition switch ON (ll).3. Check the throttle positionwith the scan tool.
ls there approx. .49 V whenthe throttle is fully clos€d andapprox, 4.5 V when the throttleis fully opened?
l||t rmittont failura, lyrtom b OKat thi! tima. Chock tor poor con-nactionr o. looao wires rt C110{TP 3.n!or} rnd ECM/PCM.
Check for an opan or 3hort in thowi.c (VCC2 linc):1. Turn the ignition switch OFF.2. Disconnect the TP sensor 3Pconnector,3. Turn the ignition switch ON (ll).4. Measure voltago betweenthe TP sensor 3P connector terminals No. 1 and No.3.
ls thero approx. 5 V?
Chccl tor .n opln in wiro IVCC2lin€l:Mgasure voltago between ECM/PCM connector terminals C18 and
R.prir opcn in the wiro bctw.enECM/PCM (C281 and TP 3€nror.ls there approx. 5 V?
Subrtituto r known-good ECM/PCM .nd rochcck. lf pro.c.ibedvoltaga i! now available, roplacotho origin.l ECM/PCM.
Wire side ol female terminrls
Terminal side of male terminals
11-134
L

L
I
(From page 11-134)
lsrhere approx.0.5 - 0.9 ko?
Chock for an open or 3hort in the
TP 3en30r:Measure resistance between the
TP sensor 3P connector terminalsNo. 2 and No. 3 with the throttle
tully closed.
ls there approx.4.5 k0?
Check for .n opon in th€ ECM/
PCM (TPS lino):1. Reconnect the TP sensor con-nector.2. Turn the ignition switch ON {ll).
3. Measure voltago between Cl8
terminal and C27 terminal on
the ECM/PCM conneclor.
Sub.lltut. . known-good ECM/
PcM lnd r.chock. ll pr6cribod
vohago b now lvallabla, aeplrca
tho originrl ECM/PCM,
ls there approx. 0.5 V when the
throttle is fully closed and
approx. 4.5 V when the throttle
is fully open€d?
Ropair ahort in th. wiro b€{weenECM/FCM lC18l .nd TP ..n.o].
TP SENSOR 3P CONNECTOR
Terminal side ol male terminals
ECM/PCM OONNCCTOR C (31PI
Wire side oI female terminals
.1,
11-135

PGM-FI System
Throttle Position (TP) Sensor (€6 - 98 Models, 39 - 00 D16Y5 engine with M/T)
The scan tool indicates Diagnostic Trouble Code (DTC) P0123: A high voltage problem in the Throttle Position(TP) sensor circuit.
TP SENSOR 3P CONNECTOR IC1lOI
sG2IGRN/BLKIvcc2{YEL/BLUI
Wire side of female terminals
ECM/PCM CONNECTOR D (16P)
SG2 (GRN/BLKI
Wire side of female terminals
1 1-136
The MIL has been reportod on.DTC P0123 is sto.ed.
Problom veritication:1. Turn the ignition switch ON {ll).2. Check the throttle positionwith the scan tool.
ls there approx. 10% when thethrottle is fully closed andapprox. 90o/o when the throttleis lully opened?
Intermittont tailuro, system is OKat thb timo, Check for ooor con-nociion3 or loos6 wiros at C110ffP s€nsor) and ECM/PCM.
Chgck to. an opan in the TP son-sot:1. Turn the ignition switch OFF.2. Disconnect the TP sensor 3Pconnector.3. Turn the ignition switch ON (ll).
4. At the harness side, measurevoltage between tho TP sensor3P connecter terminals No, 1and No.3.
ls there approx.5 V?
Ch.ck tor .n open in the wira(SG2 linel:Measure voltage between ECM/PCM connector terminals D10 andD11.
Repair op6n in the wire betwoenECM/PCM (D11) rnd TP s6nsor.ls there approx. 5 V?
Substitute a known-good ECM/PCM snd rech.ck. lf pra3cribed
voltago is now available, replscetho original ECM/PCM,

I
Throttle Position (TP) Sensor ('99 - 00 Models except D16Y5 engine with M/Tl
The scan tool indicates Diagnostic Trouble Code {DTC) P0123: A high voltage problem in the Throftle Position
{TP) sensor circuit.
TP SENSOR 3P CONNECTOR {C11OI
sG2{GRN/BLKIvoc2
{YEUBLU}
'l'Wire side of female term;nals
ECM/PCM CONNECTOR C (31PI
Wire side of femal€ terminals
(cont'd)
11-137
The MIL has been reported on
DTC P0123 is slored.
Problem verification:1. Start the engine. Hold the
engine at 3,000 rpm with no
load (in Park or neutral) until
the radiator fan comes on
then turn the ignition swatch
OFF,2. Turn the;gnition switch ON (ll).
3. Check the throttle Positionwith the scan tool.
lntormittenl tailure, 3ystom is OK
at this time. Check tor Poor con'
neqtions or loo3€ wires at C'110(TP sensorl tnd ECM/PCM.
ls there approx. 10% when the
throttle is fully closed and
approx. 90% when the throttleis fully opened?
Ch€ck for an open in the TP s6n-
soJ:1. Turn the ignition switch OFF.
2. Disconnect the TP sensor 3P
3. Turn the ignition switch ON (ll).
4. At the wire harness side, mea-
sure voltage between the TP
sensor 3P connector terminalsNo. 1 and No.3.
ls there approx. 5 V?
Check tor an open in the wire(SG2lino):
Measure voltage between ECM/
PCM connector C (31Pi terminals
C18 and C28.
Repair open in the wite betwe€nECM/PCM (Cl81and TP son.or.ls there approx. 5 V?
Substitute a known-good ECM/PCM and recheck. lf Pr$cribedvoltage is now aveilabl6. replacethe original ECM/PCM.

PGM-FI System
Throttle Position (TP) Sensor (cont'd)
- The MIL hss been.eported on.- DIC P1121 i. stored.
Problem vedficatiod:1. Turn the ignition switch ON (ll).
2. Check the throttle position
with the scan tool.
ls TP *% or higher indicatedwhen the throftle is tullyopenod?
Intermittent tailure, ryttem i! OKrtthistimo.
I Pl 121 | The sca n tool indicates Diag nostic Trouble Code (DTC) Pl 121: Throttle Position (TP) lower than expected.
*: 11.8 {D16Y5 enginei12.9 {016Y7 engine)12.2 (D16Y8 engine)13.7 (816A2 engine)
I P1122 I The scan tool indicates Diagnostic Trouble Code (DTC) P1122: Throttle Position (TP) higherthan expected.
*: 16.5 {Dl6Y5, Dl6Y8 engine}16.9 (D16Y7 engine)16.5 (81642 engine)
- The MIL ha3 be6n repoJted on.- DTC Pl122 i. llorod.
P.oblom v6dfication:1. Turn the ignition switch ON (ll).
2. Check the throttle position
with the scan tool.
ls TP'70 or l€ss indicated whenthe throttle is fully closed?Intormitt6ot frilu.o, aFtom b OKat thb timo.
1 1-138

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

PGM-FI System
(From page 11-139)
Check for a shon in the HO2S:1. Turn the ignition switch OFF.2. Disconnect the Primary HO2S(Sensor 1) 4P connector.3. Start the engine and let it idle.4. Check the Primary HO2S(Sensor 1)output voltage withthe scan tool,
Does it stay at 0.1 V or less?
Check for a short in lhe wire(PHO2S linel:1. Turn the ignition switch OFF.2. Disconnect the ECM/PCM con-nector D ('l6P).
3. Check for continuity betweenthe Primary HO2S lsensor 1)4P connector terminal No. 1and body ground.
Repair short in lhe wire b6tw6enECM/rcM (D7) and Primary llO2S{Sensor 1}.
Substitute a known-good ECM/PCM and recheck. ll symptom/indication goes awry, replaco theoriginal ECM/PCM.
Primary Heated Oxygen Sensor (Primary HO2S) (sensor 1l
('96 - 98 Models except Dl6Y5 engine with M/T) (cont'dl
PRIMARY HO2S lsonsor 1l ,tP CONNECTOR lC123l
Wire side of female terminals
11-140

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