Secondary Heated Oxygen Sensor - Honda Civic Service Manual

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
I r
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 . S t a r t t h e e n g i n e H o l d t h e
engine at 3,000 rpm with no
load (in Park or neutral) until
the radiator{an comes on
3 . C h e c k t h e S e c o n d a r Y H 0 2 S
(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 . D i s c o n n e c t t h e S e c o n d a r Y
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 a
jumper wrre,
3. Turn the ignition switch ON (ll).
4 . C h e c k t h e S e c o n d a r Y H O 2 S
{ S e n s o r 2 ) o u t P u t v o l t a g e
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/
i n d i c a t i o n g o e s a w e y , J e P l a c o
the otiginel ECM/PCM
* i 0 1 6 Y 8 e n g i n e
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