Honda CR-V 1997 Service Manual page 319

Secondary Heated Oxygen Sensor (Secondary H02S) (Sensor 2)
I
P0137
I
The scan tool indicates Diagnostic Trouble Code (OTC) P0137 : A low voltage problem in the Secondary Heated
Oxyge n Sensor (Secon dary H02S) (Sensor 2) circuit.
- The MIL has been reported on.
- OTe PO,37 is
stored.
Problem verification :
1. 0 0 the ECM/PCM Reset Pro-
cedure.
2. Start the e ngine. Hol d the
engine at 3,000 rpm with no
load (in Park or neutral) until
the radiator fan comes on.
3.
Che ck the Seco ndary H02S
(Sens or 2) o utput volta ge at
3,000
rpm
with the scan tool.
Does the voltage stay at 0.3 V
or less?
YES
Check for a short
to
the Secondary
H02S:
1. Turn the ignition switch OFF .
2.
Disconnect t he Se conda r y
H02S (Sensor 2) 4P connector.
3. Start the engine .
••
Ch eck the Seco nda ry H02 S
(Sensor 2) output with the scan
tool.
Does the voltage stay at 0.3 V
or less?
YES
Check for a short in the wire
(SH02S linel :
1. Turn the ignition switch OFF .
2.
Di sconnect the
ECM/PCM
connector (0 (16P), A (32P)·) .
3. Check for continu ity between
the Secondary H02S (Sensor
2) 4P connector terminal No. 1
and body ground.
Is there co ntinuity?
NO
Substitute a known-good
ECMI
PCM and recheck . If symptoml
indication goes away, repine
the original ECM/PCM.
*: '98 - 00 models
Intermittent failure, system is OK
at this time. Check for poor con·
NO
nection, or loos. wires at C127
(located on ECM/PCM bracket).
e721
(Secondary
H02S.
Sansor
21 and at the ECMIPCM.
NO
Replace the Secondary H02S
(Sensor 2).
YES
Repair short in the wire between
"
the ECM/PCM (014. A23*) and
the Secondary H02S (Sensor 2) .
SECONDARY H02S (Sonlo, 2)
' " CONNECTOR IC721)
SH02S
IWHTIRED)
rL..,-i~
2
3 •
Wi re side offem ale terminals
(cont'd)
11-117