Subaru Legacy III (2000-2003 year). Service manual — part 136
EN(H4SO)-156
ENGINE (DIAGNOSTICS)
DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)
Y: DTC P0138 — O2 SENSOR CIRCUIT HIGH VOLTAGE (BANK 1 SENSOR 2) —
• DTC DETECTING CONDITION:
• Two consecutive driving cycles with fault
CAUTION:
After repair or replacement of faulty parts, conduct Clear Memory Mode<Ref. to EN(H4SO)-47, OPER-
ATION, Clear Memory Mode.> and Inspection Mode <Ref. to EN(H4SO)-40, OPERATION, Inspection
Mode.> .
• WIRING DIAGRAM:
EN-01122
BATTERY
F44
B61
6
T5
B19
2
B47
MAIN RELAY
1
2
3
5
4
6
F44
1 2 3 4
5 6 7 8
C4
B14
B19
D15
C16
C5
REAR
OXYGEN SENSOR
ECM
4
1
3
1
4
3
2
8
B22
B83
B19
T5
T6
E3
B47
B19
B22
1 2 3 4
5 6 7 8
9 10 11 12
13 14 15 16
3
4
5
6
1
2
T6
4 3
2 1
2
1
FG
3
B135
B:
C: B136
D: B137
SBF-5
B136
5 6
7
2
1
9
8
4
3
23
21 22
24
10 11 12 13 14
25 26
15 16 17
18 19 20
B137
4
1
5
3
2
6
18
15
16
7 8 9 10 11
17
19 20
12 13
14
5 6 7
8
2
1
9
4
3
10
24
22 23
25
11 12 13 14 15
26
27 28
16 17 18 19
20 21
B135
B83
1 2 3 4 5 6
4
EG
: FOR G.C.C COUNTRIES MODEL
: EXCEPT FOR G.C.C COUNTRIES MODEL
FG
EG
EN(H4SO)-157
ENGINE (DIAGNOSTICS)
DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)
Step
Value
Yes
No
1
CHECK ANY OTHER DTC ON DISPLAY.
Does the Subaru Select Monitor or OBD-II
general scan tool indicate DTC P0130, P0131,
P0132 or P0134?
DTC indicated.
Check DTC refer-
ring "List of Diag-
nostic Trouble
Code (DTC)".
<Ref. to
EN(H4SO)-83, List
of Diagnostic
Trouble Code
(DTC).>
NOTE:
In this case,
CHECKING proce-
dure for P0138 is
not necessary.
2
CHECK REAR OXYGEN SENSOR DATA.
1) Warm-up the engine until engine coolant
temperature is above 70
°
C (158
°
F), and
race engine until the engine speed reaches
to 5,000 rpm and release accelerator pedal
rapidly.
2) Read data of rear oxygen sensor signal
using Subaru Select Monitor or OBD-II gen-
eral scan tool.
Does the value fluctuate?
NOTE:
•Subaru Select Monitor
For detailed operation procedure, refer to the
“READ CURRENT DATA SHOWN ON DIS-
PLAY FOR ENGINE”. <Ref. to EN(H4SO)-32,
Subaru Select Monitor.>
•OBD-II general scan tool
For detailed operation procedures, refer to the
OBD-II General Scan Tool Instruction Manual.
250 mV
3
CHECK HARNESS BETWEEN ECM AND
REAR OXYGEN SENSOR CONNECTOR.
1) Turn ignition switch to OFF.
2) Disconnect connectors from ECM and rear
oxygen sensor.
3) Measure resistance of harness between
ECM and rear oxygen sensor connector.
Connector & terminal
(B135) No. 14 — (T6) No. 4:
(B135) No. 19 — (T6) No. 3:
Does the measured value exceed the spec-
ified value?
3
Ω
Repair open circuit
in harness
between ECM and
rear oxygen sen-
sor connector.
4
CHECK HARNESS BETWEEN REAR OXY-
GEN SENSOR AND ECM CONNECTOR.
1) Turn ignition switch to OFF.
2) Disconnect connector from rear oxygen
sensor.
3) Turn ignition switch to ON.
4) Measure voltage between rear oxygen sen-
sor harness connector and engine ground
or chassis ground.
Connector & terminal
(T6) No. 4 (+) — Engine ground (
−−−−
):
Is the measured value within the specified
range?
0.2 V - 0.5 V
Replace rear oxy-
gen sensor. <Ref.
to FU(H4SO)-43,
Rear Oxygen Sen-
sor.>
Repair harness
and connector.
NOTE:
In this case, repair
the following:
• Open circuit 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(H4SO)-158
ENGINE (DIAGNOSTICS)
DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)
5
CHECK EXHAUST SYSTEM.
Check exhaust system parts.
Is there a fault in exhaust system?
NOTE:
Check the following items.
•Loose installation of portions
•Damage (crack, hole etc.) of parts
•Looseness and ill fitting of parts between front
oxygen (A/F) sensor and rear oxygen sensor
There is a fault.
Repair or replace
faulty parts.
Replace rear oxy-
gen sensor. <Ref.
to FU(H4SO)-43,
Rear Oxygen Sen-
sor.>
Step
Value
Yes
No
EN(H4SO)-159
ENGINE (DIAGNOSTICS)
DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)
MEMO:
Нет комментариевНе стесняйтесь поделиться с нами вашим ценным мнением.
Текст