Dtc P0137: Secondary Ho2S (Sensor 2) Circuit Low Voltage - Honda S2000 Service Manual

PGM-FI System
DTG Troubleshooting (cont'dl
DTC P0137: Secondary HO2S (Sensor 2)
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 secondary HO2S (Sensor 2) output
voltage at 3,000 rpm with the scan tool.
Does the voltage stay at 0.3 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
t h e s e c o n d a r y H O 2 S ( S e n s o r 2 ) a n d a t t h e E C M . I
4. Turn the ignition switch OFF.
5. Disconnect the secondary HO2S (Sensor 2) 4P
connector.
6. Start the engine.
7. Check the secondary HO2S (Sensor 2) output
voltage with the scan tool.
Does the voltage stay at 0.3 V or less?
YES Go to step 8.
N O R e p l a c e t h e s e c o n d a r y H O 2 S ( S e n s o r 2 ) . I
8 . T u r n t h e i g n i t i o n s w i t c h O F F .
9. Disconnect ECM connector C (31P).
1 1 - 5 8
10. Check for continuity between secondary HO2S
(Sensor 2) 4P connector terminal No. 2 and body
g rou nd.
SECONDARY
HO2S
ISENSOR 2l irP CONNECTOR
Terminal side of male terminals
ls there continuity?
YES Repair short in the wire between the ECM
{ C 1 5 ) a n d t h e s e c o n d a r y H O 2 S ( S e n s o r 2 ) . 1
NO - Substitute a known-good ECM and recheck
(see page 11-5). lf the sym ptom/ind ication goes
away, replace the original ECM.I