Subaru IMPREZA 2002 Service Manual page 473

DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)
ENGINE (DIAGNOSTICS)
i o to step 5.
iepair open circuit
i
harness
ietween ECM and
ear oxygen sen-
,or Connector.
Step
CHECK FAILURE CAUSE OF PO131 o r
P0132.
Inspect DTC PO1 31 or PO1 32 using "List of
Diagnostic Trouble Code (DTC)". <Ref. to
EN(S0HC)-77, List of Diagnostic Trouble Code
(DTC).>
CHECKREAROXYGENSENSORDATA.
1)Warm-up the engine until engine coolant
temperature is above 70°C (158"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-II general
scan tool.
NOTE:
*Subaru Select Monitor
For detailed operation procedure, refer to the
PLAY FOR ENGINE". <Ref. to EN(S0HC)-32,
Subaru Select Monitor.>
*OBD-ll general scan tool
For detailed operation procedures, refer to the
OBD-ll 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-
Heplace the rear
oxygen sensor.
<Ref. to
Front Oxygen
(A/
F) Sensor.>
Go to step
6 .
FU( S0HC)-43,
CHECK HARNESS BETWEEN ECM AND
REAR OXYGEN SENSOR CONNECTOR.
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
(6 136)
NO. 16
-
(€25)
NO.
3 :
CHECK HARNESS BETWEEN REAR OXY-
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 the voltage between rear oxygen
sensor harness connector and engine ground
or chassis ground.
Connector & terminal
(E25) No. 4 (+)
-
Engine ground (-):
Check
s the failure cause of
PO131
01
'01 32 in the fuel system?
Ioes the value fluctuate?
s the value fixed between 0.2
ind 0.4 V?
s the resistance more than 3
2?
s
the voltage more than 0.2 V'
Yes
:heck fuel system.
IOTE:
i
this case, it is
lot necessary to
ispect DTC
'01 36.
i o to step 7.
No
$0
to step
3.
; o to step
4.
:Ref. to NOTE:
upen circun in
harness between
rear oxygen sen-
sor and ECM con-
nector
Poor contact in
rear oxygen sen-
sor connector
Poor contact in
ECM connector
EN(S0HC)-I 49