DIAGNOSTIC PROCEDURE
WITH
DIAGNOSTIC TROUBLE CODE (DTC)
ENGINE (DIAGNOSTICS)
Step
CHECK FAILURE CAUSE
OF
PO131
or
PO1 32.
Inspect DTC PO1
31
or
PO1
32 using “List of
Diagnostic Trouble Code (DTC)”. <Ref.
to
EN(D0HC TURBO)-80, List of Diagnostic
Trouble Code (DTC).>
CHECK REAR OXYGEN SENSOR DATA.
1)Warm-up the engine until engine coolant
temperature is above 70°C
(1
58”F), and keep
the engine speed at 2,000 rpm
to
3,000
rpm for
two minutes.
2)Read the data of rear oxygen sensor signal
using Subaru Select Monitor or OBD-ll general
scan tool.
NOTE:
OSubaru Select Monitor
For detailed operation procedure, refer to the
PLAY FOR ENGINE”. <Ref. to EN(D0HC
TURBO)-38, Subaru Select Monitor.>
.OBD-ll general scan tool
For detailed operation procedures, refer
to the
OBD-I1 General Scan Tool Instruction Manual.
CHECKREAROXYGENSENSORDATA.
Read the data of rear oxygen sensor signal
using Subaru Select Monitor or OBD-II Gen-
eral Scan Tool.
“READ CURRENT DATA SHOWN
ON
DIS-
CHECK HARNESS BETWEEN ECM AND
REAROXYGENSENSORCONNECTOR.
1)Turn the ignition switch to
OFF.
2)Disconnect the connectors from ECM and
rear oxygen sensor.
3)Measure the resistance of harness between
ECM and rear oxygen sensor connector.
Connector
&
terminal
(6135)
NO.
26
-
(B19)
NO.
4:
CHECKHARNESSBETWEENREAROXY-
GEN SENSOR AND ECM CONNECTOR.
1)Turn the ignition switch
to
OFF.
2)Disconnect the connector from rear oxygen
sensor.
3)Turn the ignition switch
to ON.
4)Measure voltage between rear oxygen sen-
sor harness connector and engine ground or
chassis ground.
Connector
&
terminal
(B19)
No.
3
(+)
-
Engine ground
(-):
-
CHECK EXHAUST SYSTEM.
Check exhaust system parts.
NOTE:
Check the following items.
*Loose installation of portions
.Damage (crack, hole etc.) of parts
.Looseness and
ill
fitting of parts between front
oxygen (NF) sensor and rear oxygen sensor
Check
;
the failure cause of PO1
31
or
‘01
32 in the fuel system?
boes the value fluctuate?
s
the value fixed between
0.2
Ind 0.4
V?
;the resistance more than
3
2?
5
the voltage more than 0.2
VI
s
there a fault in exhaust sys-
em?
Yes
;heck fuel system.
\IOTE:
n this case, it is
lot
necessary
to
nspect DTC
’01
36.
30
to
step
7.
30
to
step
5.
Repair open circuit
n harness
Detween ECM and
rear oxygen sen-
sor connector.
Replace the rear
oxygen sensor.
<Ref. to FU(D0HC
TURBO)-44, Rear
Oxygen Sensor.>
Repair or replace
faulty parts.
No
;o
to step 3.
io
to step
4.
3eplace the rear
)xygen sensor.
:Ref.
to
FU(D0HC
rURBO)-44, Rear
lxygen Sensor.>
30
to step
6.
3epair harness
md connector.
\IOTE:
n this case, repai
he following:
1
Open circuit in
iarness between
‘ear oxygen sen-
;or and ECM con-
lector
1
Poor contact in
‘ear oxygen sen-
jot‘ connector
1
Poor contact in
XM connector
3eplace the rear
ixygen sensor.
:Ref. to FU(D0HC
TURBO)-44, Rear
3xygen Sensor.>
EN(D0HC TURBO)-I49
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