Subaru Legacy III (2000-2003 year). Service manual — part 337
EN(H6DO)-150
ENGINE (DIAGNOSTICS)
DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)
R: DTC P0122 — THROTTLE/PEDAL POSITION SENSOR/SWITCH “A” CIR-
CUIT LOW INPUT —
• DTC DETECTING CONDITION:
• Immediately at fault recognition
• TROUBLE SYMPTOM:
• Erroneous idling
• Engine stalls.
• Poor driving performance
CAUTION:
After repair or replacement of faulty parts, conduct Clear Memory Mode <Ref. to EN(H6DO)-54, OP-
ERATION, Clear Memory Mode.> and Inspection Mode <Ref. to EN(H6DO)-47, OPERATION, Inspec-
tion Mode.>.
• WIRING DIAGRAM:
EN-00814
19
7
9
13
15
16
1
2
3
E1
B20
E13
THROTTLE
POSITION
SENSOR
E13
1 2 3
5
8
B83
B20
B135
ECM
B83
B135
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
1 2 3 4
5 6 7 8
9 10 11 12
13 14 15 16
1 2 3 4
5 6 7 8 9 10
11 12
19 20
13 14 15 16 17 18
EN(H6DO)-151
ENGINE (DIAGNOSTICS)
DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)
Step
Value
Yes
No
1
CHECK CURRENT DATA.
1) Start engine.
2) Read data of throttle position sensor signal
using Subaru Select Monitor or OBD-II gen-
eral scan tool.
Is the measured value less than the speci-
fied value?
NOTE:
• Subaru Select Monitor
For detailed operation procedure, refer to the
“READ CURRENT DATA FOR ENGINE”.
<Ref. to EN(H6DO)-34, Subaru Select Moni-
tor.>
• OBD-II general scan tool
For detailed operation procedures, refer to the
OBD-II General Scan Tool Instruction Manual.
0.1 V
Even if MI lights
up, the circuit has
returned to a nor-
mal condition at
this time. A tempo-
rary poor contact
of the connector
may be the cause.
NOTE:
In this case, repair
the following:
• Poor contact in
throttle position
sensor connector
• Poor contact in
ECM connector
• Poor contact in
coupling connector
2
CHECK INPUT SIGNAL FOR ECM.
Measure voltage between ECM connector and
chassis ground while throttle valve is fully
closed.
Connector & terminal
(B135) No. 7 (+) — Chassis ground (
−−−−
):
Does the measured value exceed the specified
value?
4.5 V
3
CHECK INPUT SIGNAL FOR ECM.
Measure voltage between ECM connector and
chassis ground.
Connector & terminal
(B135) No. 7 (+) — Chassis ground (
−−−−
):
Does the voltage change more than the speci-
fied value by shaking harness and connector
of ECM while monitoring the value with voltage
meter?
4.5 V
Repair poor con-
tact in ECM con-
nector.
Contact SUBARU
distributor service.
NOTE:
Inspection by DTM
is required, be-
cause probable
cause is deteriora-
tion of multiple
parts.
4
CHECK INPUT SIGNAL FOR ECM.
Measure voltage between ECM connector and
chassis ground.
Connector & terminal
(B135) No. 9 (+) — Chassis ground (
−−−−
):
Is the measured value less than the specified
value?
0.1 V
5
CHECK INPUT SIGNAL FOR ECM. (USING
SUBARU SELECT MONITOR.)
Measure voltage between ECM connector and
chassis ground.
Does the voltage change more than the speci-
fied value by shaking harness and connector
of ECM while monitoring the value with Subaru
Select Monitor?
0.1 V
Repair poor con-
tact in ECM con-
nector.
EN(H6DO)-152
ENGINE (DIAGNOSTICS)
DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)
6
CHECK HARNESS BETWEEN ECM AND
THROTTLE POSITION SENSOR CONNEC-
TOR.
1) Turn ignition switch to OFF.
2) Disconnect connectors from throttle posi-
tion sensor.
3) Turn ignition switch to ON.
4) Measure voltage between throttle position
sensor connector and engine ground.
Connector & terminal
(E13) No. 1 (+) — Engine ground (
−−−−
):
Does the measured value exceed the spec-
ified value?
4.5 V
Repair harness
and connector.
NOTE:
In this case, repair
the following:
• Open circuit in
harness between
throttle position
sensor and ECM
connector
• Poor contact in
throttle position
sensor connector
• Poor contact in
ECM connector
• Poor contact in
coupling connector
• Poor contact in
joint connector
7
CHECK HARNESS BETWEEN ECM AND
THROTTLE POSITION SENSOR CONNEC-
TOR.
1) Turn ignition switch to OFF.
2) Measure resistance of harness between
ECM connector and throttle position sensor
connector.
Connector & terminal
(B135) No. 9 — (E13) No. 3:
Is the measured value less than the speci-
fied value?
1
Ω
Repair harness
and connector.
NOTE:
In this case, repair
the following:
• Open circuit in
harness between
throttle position
sensor and ECM
connector
• Poor contact in
ECM connector
• Poor contact in
throttle position
sensor connector
• Poor contact in
coupling connector
8
CHECK HARNESS BETWEEN ECM AND
THROTTLE POSITION SENSOR CONNEC-
TOR.
Measure resistance of harness between throt-
tle position sensor connector and engine
ground.
Connector & terminal
(E13) No. 3 — Engine ground:
Is the measured value less than the specified
value?
10
Ω
Repair ground
short circuit in har-
ness between
throttle position
sensor and ECM
connector.
9
CHECK POOR CONTACT.
Check poor contact in throttle position sensor
connector.
Is there poor contact in throttle position sensor
connector?
There is poor contact.
Repair poor con-
tact in throttle posi-
tion sensor
connector.
Replace throttle
position sensor.
<Ref. to
FU(H6DO)-33,
Throttle Position
Sensor.>
Step
Value
Yes
No
EN(H6DO)-153
ENGINE (DIAGNOSTICS)
DIAGNOSTIC PROCEDURE WITH DIAGNOSTIC TROUBLE CODE (DTC)
MEMO:
Нет комментариевНе стесняйтесь поделиться с нами вашим ценным мнением.
Текст