Dtc P0131: Primary Ho2S (Sensor 1) Circuit Low Voltage - Honda S2000 Service Manual

DTC P0131: Primary HO2S (Sensor 1) Circuit
Low Voltage
1 . R e s e t t h e E C M { s e e p a g e 1 1 - 4 } .
2. Start the engine. Hold the engine at 3,000 rpm with
n o l o a d ( i n n e u t r a l ) u n t i l t h e r a d i a t o r f a n c o m e s o n .
3. Check the primary HO2S {Sensor 1) output voltage
with the scan tool during acceleration using wide
open throttle.
Does the voltage stay at 0.5 V or less?
YES Go to step 4.
NO Intermittent failure, system is OK at this time.
Check for poor connections or loose terminals at
the primary HO2S (Sensor
'1)
and at the ECNil. t
C h e c k t h e f u e l p r e s s u r e ( s e e p a g e 1 1 - 1 0 5 ) .
ls it notmal?
YES Go to step 5.
N O R e p a i r t h e f u e l s u p p l y s y s t e m . l
Turn the ignition switch OFF.
Disconnect the primary HO2S {Sensor 1) 4P
connector.
S t a r t t h e e n g i n e a n d l e t i t i d l e .
C h e c k t h e p r i m a r y H O 2 S ( S e n s o r 1 ) o u t p u t v o l t a g e
with the scan tool.
Does it stay at 0.5 V or less?
YES Go to step 9.
N O R e p l a c e t h e p r i m a r y H O 2 S ( S e n s o r 1 ) . I
Turn the ignition switch OFF.
D i s c o n n e c t t h e E C M c o n n e c t o r C { 3 1 P ) .
5 .
6 .
7 .
8 ,
9 .
1 0 .
1 1. Check for continuity between primary HO2S
( S e n s o r 1 ) 4 P c o n n e c t o r t e r m i n a l N o , 1 a n d b o d y
g rou nd.
PRIMARY HO2S lsensor 1) ilP CONNECTOR
W | l e s r d e o l l e m a l e t e r m r n a l s
Is there continuity?
YES Repair short in the wire between the ECM
( C 1 6 ) a n d t h e p r i m a r y H O 2 S ( S e n s o r 1 ) . 1
NO Substitute a known'good ECM and recheck
(see page 11-5). lf the symptom/indication goes
a w a y , r e p l a c e t h e o r i g i n a l E C M . I
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