SUBARU LEGACY 1995 Service Repair Manual

OBD0323
AC: DTC P0403
—EXHAUST GAS RECIRCULATION CIRCUIT
MALFUNCTION (EGRSOL)—
OBD0324A
DESCRIPTION:
The EGR solenoid valve is situated between the BPT and
EGR valve. EGR solenoid valve is opened by a signal
emitted from the ECM. Therefore, throttle port pressure is
transmitted to diaphragm of EGR valve.
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. <Ref. to [T11BN0].>
2.Check output signal from ECM.

3.Check harness.
4.Check harness.
5.Check EGR solenoid valve.
6.Check power supply to EGR solenoid valve.
CAUTION:
After repair or replacement of faulty parts, conduct
CLEAR MEMORY and INSPECTION MODES. <Ref. to
[T3D0] and [T3E0].>




235
2-7ON-BOARD DIAGNOSTICS II SYSTEM
11. Diagnostics Chart with Trouble Code

WIRING DIAGRAM:

LHD model
OBD0325
236
2-7ON-BOARD DIAGNOSTICS II SYSTEM
11. Diagnostics Chart with Trouble Code

WIRING DIAGRAM:

RHD model
B2M0454
1
CHECK TRANSMISSION TYPE.
Refer to flow chart on page 235.
OBD0326A
2
CHECK OUTPUT SIGNAL FROM ECM.
1) Turn ignition switch to ON.
2) Measure signal voltage between ECM and body.
: Connector & terminal
(B84) No. 60—Body / 10 V, or more
: Go to step 3.
: Go to step 4.
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2-7ON-BOARD DIAGNOSTICS II SYSTEM
11. Diagnostics Chart with Trouble Code

OBD0326A
3
CHECK HARNESS.
1) Turn ignition switch to OFF.
2) Disconnect connector from EGR solenoid valve.
3) Turn ignition switch to ON.
4) Measure voltage between ECM and body.
: Connector & terminal
(B84) No. 60—Body / 10 V, or more
: Repair short circuit of harness and replace ECM.
NOTE:
The harness between ECM and EGR solenoid valve is in
short circuit.
: Go to next step.
OBD0327
5) Turn ignition switch to OFF.
6) Measure resistance between EGR solenoid valve ter-
minals.
: Terminals
No. 1—No. 2/1Ω, or less
: Replace EGR solenoid valve and ECM.
: Go to next.
: Is there poor contact in ECM connector?
: Replace ECM.
: Repair poor contact in ECM connector.
OBD0678A
4
CHECK HARNESS.
1) Turn ignition switch to OFF.
2) Disconnect connectors from EGR solenoid valve and
ECM.
3) Measure resistance of harness connector between
EGR solenoid valve and body.
: Connector & terminal
(E18) No. 2—Body / 10Ω, or less
238
2-7ON-BOARD DIAGNOSTICS II SYSTEM
11. Diagnostics Chart with Trouble Code

: Repair short circuit of harness between ECM con-
nector and EGR solenoid valve connector.
: Go to the next step.
OBD0677A
4) Measure resistance of harness connector between
ECM and EGR solenoid valve.
: Connector & terminal
(B84) No. 60—(E18) No. 2 / 10Ω, or less
: Go to step 5.
: Repair open circuit of harness between ECM con-
nector and EGR solenoid valve connector.
OBD0327
5
CHECK EGR SOLENOID VALVE.
Measure resistance between connector terminals of EGR
solenoid valve.
: Terminals
No. 1—No. 2 / 10—100Ω
: Go to step 6.
: Replace EGR solenoid valve.
OBD0328A
6CHECK POWER SUPPLY TO EGR SOLENOID
VA LV E .
1) Turn ignition switch to ON.
2) Measure voltage between EGR solenoid valve harness
connector and body.
: Connector & terminal
(E18) No. 1—Body / 10 V, or more
: Confirm good connection at EGR solenoid valve
connector.
: Repair open circuit of harness between main relay
connector and EGR solenoid valve connector.
239
2-7ON-BOARD DIAGNOSTICS II SYSTEM
11. Diagnostics Chart with Trouble Code

OBD0329
AD: DTC P0420
—CATALYST SYSTEM EFFICIENCY BELOW
THRESHOLD (CAT)—
DESCRIPTION:

The three-way catalyst is an oval shaped honeycomb
monolith ceramic. Its porous surface is coated with plati-
num and rhodium.

The catalyst is used to reduce HC, CO and NOx in
exhaust gases, and permits simultaneous oxidation and
reduction.
DTC DETECTING CONDITION:

Immediately at fault recognition
TROUBLE SYMPTOM:

Engine stalls.

Idle mixture is out of specifications.
240
2-7ON-BOARD DIAGNOSTICS II SYSTEM
11. Diagnostics Chart with Trouble Code

1.Check any other DTC P0130, P0133, P0135,
P0136, P0139 and P0141 on display.
2.Check exhaust system.
3.Check rear catalytic converter.
CAUTION:
After repair or replacement of faulty parts, conduct
CLEAR MEMORY and INSPECTION MODES. <Ref. to
[T3D0] and [T3E0].>
WIRING DIAGRAM:

LHD model
B2M0626


241
2-7ON-BOARD DIAGNOSTICS II SYSTEM
11. Diagnostics Chart with Trouble Code

WIRING DIAGRAM:

RHD model
B2M0455
242
2-7ON-BOARD DIAGNOSTICS II SYSTEM
11. Diagnostics Chart with Trouble Code

1CHECK ANY OTHER DTC P0130, P0133,
P0135, P0136, P0139 AND P0141 ON DIS-
PLAY.
: Check that Subaru Select Monitor or the
OBD-II general scan tool shows P0130,
P0133, P0135, P0136, P0139 and P0141.
: Inspect the relevant DTC using“11. Diagnostics
Chart with Trouble Code”.
Inspection of P0420 is not necessary after above.
: Go to step 2.
2
CHECK EXHAUST SYSTEM.
Check for gas leaks or air suction caused by loose or dis-
located nuts and bolts, and open hole at exhaust pipes.
: Check the following position of exhaust
sys-
tem.

Between cylinder head and front exhaust pipe.

Between front exhaust pipe and front catalytic
converter.

Between front catalytic converter and rear cata-
lytic converter.
: Repair or replace exhaust system.
: Go to step 3.
3
CHECK REAR CATALYTIC CONVERTER.
1) Separate rear catalytic converter from rear exhaust
pipe.
: Is there damage at rear face of rear cata-
lyst?
: Replace front and rear catalytic converters.
: Go to next step.
2) Remove front catalytic converter.
: Is there damage at rear face or front face of
front catalyst?
If there is damage in front catalyst, replace front catalytic
converter.
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2-7ON-BOARD DIAGNOSTICS II SYSTEM
11. Diagnostics Chart with Trouble Code

OBD0331
AE: DTC P0441
—EVAPORATIVE EMISSION CONTROL
SYSTEM INCORRECT PURGE FLOW
(CPC
—F)—
DESCRIPTION:

The evaporative emission control system is employed to
prevent evaporative fuel from being discharged into ambi-
ent atmosphere. This system includes a canister, purge
control solenoid valve, fuel cut valve, their connecting lines,
etc.

Gasoline vapor evaporated from the fuel tank is intro-
duced into the canister located in the engine compartment
through the evaporation line, and is absorbed on activated
carbon in it. A fuel cut valve is also incorporated on the tank
fuel line.

The purge control solenoid valve is controlled by the
ECM and provides optimal purge control according to the
engine coolant temperature, engine load and vehicle
speed.
OBD0332A
244
2-7ON-BOARD DIAGNOSTICS II SYSTEM
11. Diagnostics Chart with Trouble Code