Subaru IMPREZA 2002 Service Manual page 463

4
DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)
ENGINE (DIAGNOSTICS)
30 to step 6.
Go to step 4.
Repair open circui
between ECM ant
front oxygen (NF)
sensor.
Go to step 5.
~
Step
CHECK ANY OTHER DTC ON DISPLAY.
30 to step 2.
Yes
Inspect DTC
PO1 31, PO1 32,
PO031 or PO032
using "List of Diag-
nostic Trouble
Code (DTC)".
<Ref. to
List of Diagnostic
Trouble Code
(DTC).>
Go to step
3 .
EN(SOHC)-77,
CHECK FRONT OXYGEN (NF) SENSOR DA
TA.
1)Start the engine.
2)While observing the Subaru Select Monitor
or OBD-ll general scan tool screen, warm-up
the engine until coolant temperature is above
70°C (1 60°F).
If the engine is already warmed-up, operate ai
idle speed for at least 1 minute.
3)Read the data of front oxygen (NF) sensor
signal using Subaru Select Monitor or OBD-II
general scan tool.
NOTE:
OSubaru Select Monitor
For detailed operation procedure, refer to the
"READ CURRENT DATA FOR ENGINE. <Rei
to EN(S0HC)-32, Subaru Select Monitor.>
*OBD-ll general scan tool
For detailed operation procedures, refer to tht
OBD-ll General Scan Tool Instruction Manual
CHECK FRONT OXYGEN (NF) SENSOR DA-
TA.
Race the engine at speeds from idling to 5,000
rpm for a total of 5 cycles.
NOTE:
To increase engine speed to 5,000 rpm, slowly
depress accelerator pedal, taking approximate-
ly 5 seconds, and quickly release accelerator
pedal to decrease engine speed.
CHECK HARNESS BETWEEN ECM AND
FRONT OXYGEN (NF) SENSOR.
1)Turn the ignition switch to OFF.
2)Disconnect the connector from ECM and
front oxygen (NF) sensor connector.
3)Measure the resistance between ECM and
front oxygen (NF) sensor.
Connector & terminals
1
(8136)
NO.
6
-
(€24) NO. 3:
(8136) NO. 7
-
(E24) NO. 4:
(8136) NO. 19
-
(€24) NO. 1:
(8136) NO. 20
-
(€24) NO. 6:
Check
Does the Subaru Select Moni-
:or
or OBD-ll general scan tool
ndicate DTC PO1 31, PO1 32,
PO031 or P0032?
;the value more than 1 .I fori
loment?
Is the value equal to or more
than 0.85 and equal to less
than 1 .I 5 in idling?
s the resistance less than 5
2?
No
io to step 4.
EN(SOHC)-139