SUBARU LEGACY 1995 Service Repair Manual

OBD0304
AA: DTC P0340
—CAMSHAFT POSITION SENSOR CIRCUIT
MALFUNCTION (CAM)—
OBD0305A
DESCRIPTION:

The camshaft position sensor is located on the left-hand
camshaft support to detect the combustion cylinder at any
one moment.

It is designed so that the ECM accurately reads the
number of pulses which occur when protrusions provided
on the back of the LH camshaft-drive sprocket cross the
sensor.
Internal construction and the basic operating principle of
the camshaft position sensor are similar to those of the
crankshaft position sensor. A total of seven protrusions
(one each at two locations, two at one location and three
at one location) are arranged in four equal parts of the
sprocket.
DTC DETECTING CONDITION:

Immediately at fault recognition
TROUBLE SYMPTOM:

Engine stalls.

Failure of engine to start
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11. Diagnostics Chart with Trouble Code

1.Check harness.
2.Check camshaft position sensor.
CAUTION:
After repair or replacement of faulty parts, conduct
CLEAR MEMORY and INSPECTION MODES.

WIRING DIAGRAM:
OBD0115

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11. Diagnostics Chart with Trouble Code

OBD0720A
1
CHECK HARNESS.
1) Turn ignition switch to OFF.
2) Disconnect connector from camshaft position sensor.
3) Measure resistance of harness between camshaft posi-
tion sensor connector and body.
: Connector & terminal
(E15) No. 1—Body/100 kΩ, or more
: Check and repair the following items.

Open circuit of harness between camshaft
position sensor connector and ECM connector

Poor contact in ECM connector

Poor contact in the coupling connector (B20)
: Go to next.
OBD0720A
: Connector & terminal
(E15) No. 1—Body/10Ω, or less
: Repair short circuit of harness between camshaft
position sensor connector and ECM connector.
NOTE:
The harness between both connectors is shielded. Repair
short circuit of harness together with shield.
: Go to next.
OBD0721A
: Connector & terminal
(E15) No. 2—Body/10Ω, or less
: Check and repair the following items.

Open circuit of harness between camshaft
position sensor connector and ECM connector

Poor contact in ECM connector

Poor contact in the coupling connector (B20)
: Go to step 2.
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2
CHECK CAMSHAFT POSITION SENSOR.
: Check for secure tightening of the installa-
tion bolts of the camshaft position sensor.
: Tighten securely.
: Go to the next step.
G2M0639
1) Remove camshaft position sensor.
2) Measure resistance between connector terminals of
camshaft position sensor.
: Terminals
No. 1—No. 2/1—4kΩ
: Repair poor contact in camshaft position sensor
connector.
: Replace camshaft position sensor.
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11. Diagnostics Chart with Trouble Code

OBD0315
AB: DTC P0400
—EXHAUST GAS RECIRCULATION FLOW
MALFUNCTION (EGR)—
DESCRIPTION:

The EGR system aims at reduction of NOx by lowering
the combustion temperature through recirculation of a part
of exhaust gas into cylinders via the intake manifold.

This system consists of the EGR valve, the EGR sole-
noid valve and BPT (Back Pressure Transducer). The EGR
valve is operated by the vacuum pressure from throttle
body via BPT and controls the exhaust gas flow from the
exhaust manifold to the intake manifold by open/close
operation of the EGR valve.
The EGR solenoid valve is controlled by the ECM accord-
ing to the engine driving condition and opens/closes the
vacuum line from the BPT to the EGR valve diaphragm.
The BPT controls the vacuum pressure to control the
amount of EGR according to the engine load.
OBD0316A
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11. Diagnostics Chart with Trouble Code

OBD0317A

The EGR valve is situated between the exhaust manifold
and intake manifold. After opening EGR solenoid valve,
EGR valve is opened for receiving throttle port pressure on
diaphragm. Then, part of the exhaust gas is recirculated
into intake manifold.
DTC DETECTING CONDITION:

Two consecutive trips with fault
TROUBLE SYMPTOM:

Poor driving performance on low engine speed
1.Check transmission type.
AT
MT
Check AT/MT identification circuit. [T11BN0].>
2.Check DTC P0105, P0106, P0403, P1102 on
display.

3.Check vacuum hose.
4.Check operation of EGR system.
Confirmation of actual driving
pattern
CAUTION:
Before confirmation of actual driving pattern, conduct
CLEAR MEMORY and INSPECTION MODES. [T3D0] and [T3E0].>




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11. Diagnostics Chart with Trouble Code

WIRING DIAGRAM:

LHD model
OBD0318
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11. Diagnostics Chart with Trouble Code

WIRING DIAGRAM:

RHD model
B2M0453
1
CHECK TRANSMISSION TYPE.
Refer to flow chart on page 230.
2CHECK DTC P0105, P0106, P0403, P1102 ON
DISPLAY.
: Check that Subaru Select Monitor or OBD-II
general scan tool shows P0105, P0106,
P0403 and P1102.
:
Inspect the relevant DTC using“11. Diagnostics
Chart with Trouble Code [T1100]”.

Manually check that EGR valve diaphragm is
not stuck.

In this case, inspection of P0400 is not neces-
sary after the above items.
WARNING:
Be careful when checking EGR valve, since it may be
extremely hot.
After checking the above item, go to
CONFIRMATION
OF ACTUAL DRIVING PATTERN.
: Go to step 3.
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11. Diagnostics Chart with Trouble Code

3
CHECK VACUUM HOSE.
: Check vacuum hoses for disconnection,
leakage and clogging.
: Check and repair the following items.

Two lines of pipes and hoses running between
throttle body and BPT

Pipe and hose line connecting BPT and EGR
solenoid valve

Hose between EGR solenoid valve and EGR
valve

BPT pressure transmitting hose
: Go to step 4.
4
CHECK OPERATION OF EGR SYSTEM.
1) Turn ignition switch to OFF.
2) Connect the test mode connector.
3) Turn ignition switch to ON.
: Does EGR solenoid valve produce operating
sound?
: Replace EGR solenoid valve.
: Go to next step.
4) Turn ignition switch to OFF.
5) Disconnect connector from EGR solenoid valve.
6) Connect 12 V battery’s ground
terminal to one ter-
minal of the EGR solenoid valve. Then connect 12 V bat-
tery’sterminal to the other terminal of it.
CAUTION:
Do not use the 12 V battery installed in the vehicle,
because the electrical system may be damaged.
7) Start the engine.
: Open throttle valve by 5 to 10 degrees and
visually check EGR valve operation.
: Possibly EGR valve malfunction may be due to
freezing or clogging by foreign matter. At this point
in time do not replace EGR valve, since it is not
faulty. And after the checking, go to
CONFIR-
MATION OF ACTUAL DRIVING PATTERN.
NOTE:
If malfunction is detected again in the confirmation of actual
driving pattern, EGR valve is faulty. Go to next
.
: Go to next.
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11. Diagnostics Chart with Trouble Code

: Is there clogging in the gas outlets of intake
manifold or cylinder head, checking by
breathing into the outlets?
: Repair or replace intake manifold or cylinder
head. And go to
CONFIRMATION OF
ACTUAL DRIVING PATTERN.
: Replace EGR valve. And go toCONFIRMA-
TION OF ACTUAL DRIVING PATTERN.
CONFIRMATION OF ACTUAL DRIVING
PATTERN.
1) Conduct CLEAR MEMORY and INSPECTION MODES.

2) Connect Subaru select monitor to its data link connec-
tor.
3) Start and warm-up the engine until the radiator fan
makes one complete rotation. (All accessory switches are
OFF.)
4) Turn Subaru select monitor switch to ON.
5) Designate mode using function key.
Function mode: FA4
6) Drive at 55±3 MPH (88±5 km/h) until the LED No. 5 is
turned on.
NOTE:
Keep the throttle valve opening at the same degree, since
diagnosis will be interrupted when the opening varies.
Diagnosis starts in 190 seconds after starting engine and
takes 4 seconds.
Put the gear to“D”range for the diagnosis.
7) Designate mode using function key.
Function mode: FB0
8) Confirm the“No trouble”indication on Subaru select
monitor.
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11. Diagnostics Chart with Trouble Code