1996 SUBARU LEGACY Fuel system

H2M1406
BN: DTC P1400
—FUEL TANK PRESSURE CONTROL
SOLENOID VALVE CIRCUIT MALFUNCTION
(PCVSOL)—
DTC DETECTING CONDITION:

Two consecutive trips with fault
10BN1Check output signal from ECM.

10BN2Check harness between fuel tank pressure
control solenoid valve and ECM connector.
10BN3Check harness between fuel tank pressure
control solenoid valve and ECM connector.
10BN4Check fuel tank pressure control solenoid
valve.
10BN5Check power supply to fuel tank pressure
control solenoid valve.
CAUTION:
After repair or replacement of faulty parts, conduct
CLEAR MEMORY and INSPECTION MODES.




331
2-7ON-BOARD DIAGNOSTICS II SYSTEM
10. Diagnostics Chart with Trouble Code

H2M1408B
10BN1
CHECK OUTPUT SIGNAL FROM ECM.
1) Turn ignition switch to ON.
2) Measure voltage between ECM and chassis ground.
: Connector & terminal
(B84) No. 10 (+)—Chassis ground ():
Is the voltage more than 10 V?
: Go to step10BN2.
: Go to step10BN3.
H2M1408B
10BN2CHECK HARNESS BETWEEN FUEL
TANK PRESSURE CONTROL SOLENOID
VALVE AND ECM CONNECTOR.
1) Turn ignition switch to OFF.
2) Disconnect connector from fuel tank pressure control
solenoid valve.
3) Turn ignition switch to ON.
4) Measure voltage between ECM and chassis ground.
: Connector & terminal
(B84) No. 10 (+)—Chassis ground ():
Is the voltage more than 10 V?
: Repair short circuit in harness and replace ECM.
NOTE:
The harness between ECM and fuel tank pressure control
solenoid valve is in short circuit.
: Go to next step 5).
B2M0929
5) Turn ignition switch to OFF.
6) Measure resistance between fuel tank pressure control
solenoid valve terminals.
: Terminals
No. 1—No. 2:
Is the resistance less than 1Ω?
: Replace fuel tank pressure control solenoid valve
and ECM.
: Go to next.
: Is there poor contact in ECM connector?
: Repair poor contact in ECM connector.
: Replace ECM.
334
2-7ON-BOARD DIAGNOSTICS II SYSTEM
10. Diagnostics Chart with Trouble Code

B2M0930A
10BN3CHECK HARNESS BETWEEN FUEL
TANK PRESSURE CONTROL SOLENOID
VALVE AND ECM CONNECTOR.
1) Turn ignition switch to OFF.
2) Disconnect connectors from fuel tank pressure control
solenoid valve and ECM.
3) Measure resistance of harness between fuel tank pres-
sure control solenoid valve connector and chassis ground.
: Connector & terminal
(R68) No. 2—Chassis ground:
Is the resistance less than 10Ω?
: Repair short circuit in harness between ECM and
fuel tank pressure control solenoid valve connec-
tor.
: Go to next step 4).
B2M0931A
4) Measure resistance of harness between ECM and fuel
tank pressure control solenoid valve connector.
: Connector & terminal
(B84) No. 10—(R68) No. 2:
Is the resistance less than 1Ω?
: Go to step10BN4.
: Repair harness and connector.
NOTE:
In this case, repair the following:

Open circuit in harness between ECM and fuel tank
pressure control solenoid valve connector

Poor contact in coupling connectors (B98 (LHD)/B97
(RHD), and R57)
B2M0929
10BN4CHECK FUEL TANK PRESSURE CON-
TROL SOLENOID VALVE.
Measure resistance between fuel tank pressure control
solenoid valve terminals.
: Terminals
No. 1—No. 2:
Is the resistance between 10 and 100Ω?
: Go to step10BN5.
: Replace fuel tank pressure control solenoid valve.
335
2-7ON-BOARD DIAGNOSTICS II SYSTEM
10. Diagnostics Chart with Trouble Code

B2M0932A
10BN5CHECK POWER SUPPLY TO FUEL TANK
PRESSURE CONTROL SOLENOID
VA LV E .
1) Turn ignition switch to ON.
2) Measure voltage between fuel tank pressure control
solenoid valve and chassis ground.
: Connector & terminal
(R68) No. 1 (+)—Chassis ground ():
Is the voltage more than 10 V?
: Go to next.
: Repair harness and connector.
NOTE:
In this case, repair the following:

Open circuit in harness between main relay and fuel tank
pressure control solenoid valve connector

Poor contact in coupling connectors (B97 and R57)

Poor contact in main relay connector
: Is there poor contact in fuel tank pressure
control solenoid valve connector?
: Repair poor contact in fuel tank pressure control
solenoid valve connector.
: Contact with SOA service.
NOTE:
Inspection by DTM is required, because probable cause is
deterioration of multiple parts.
336
2-7ON-BOARD DIAGNOSTICS II SYSTEM
10. Diagnostics Chart with Trouble Code

H2M1410
BO: DTC P1401
—FUEL TANK PRESSURE CONTROL
SYSTEM FUNCTION PROBLEM (PCV
—F)—
DTC DETECTING CONDITION:

Two consecutive trips with fault
10BO1Check fuel tank pressure control solenoid
valve.
CAUTION:
After repair or replacement of faulty parts, conduct
CLEAR MEMORY and INSPECTION MODES.

WIRING DIAGRAM:

LHD Model
B2M0928
337
2-7ON-BOARD DIAGNOSTICS II SYSTEM
10. Diagnostics Chart with Trouble Code

WIRING DIAGRAM:

RHD Model
B2M1020
OBD0005B
10BO1CHECK FUEL TANK PRESSURE CON-
TROL SOLENOID VALVE.
1) Turn ignition switch to OFF.
2) Connect test mode connector.
3) Turn ignition switch to ON.
: Does fuel tank pressure control solenoid
valve produce operating sound?
NOTE:
Fuel tank pressure control solenoid valve operation check
can also be executed using Subaru Select Monitor (Func-
tion mode: FD07). For the procedure, refer to“COMPUL-
SORY VALVE OPERATION CHECK MODE”2-7 [T3F0].
: Check evaporative emission control system.

: Replace fuel tank pressure control solenoid valve.
338
2-7ON-BOARD DIAGNOSTICS II SYSTEM
10. Diagnostics Chart with Trouble Code

H2M1411
BP: DTC P1402
—FUEL LEVEL SENSOR CIRCUIT
MALFUNCTION (FLVL)—
DTC DETECTING CONDITION:

Two consecutive trips with fault
10BP1Check speedometer and tachometer operation
in combination meter.


10BP2Check ground circuit of combination meter.
10BP3Check input signal for ECM. (Using voltage
meter and Subaru Select Monitor.)
10BP4Check fuel level sensor.
10BP5Check fuel sub level sensor.
10BP6Check harness between fuel pump and fuel
sub meter unit connector.
10BP7Check ground circuit of fuel level sensor.
10BP8Check harness between ECM and fuel pump
connector.
10BP9
(LHD)
10BP10
(RHD)
Check harness between ECM, combination
meter and fuel pump connector.
10BP11Check harness between combination meter
and fuel pump connector.
10BP12Check combination meter.
CAUTION:
After repair or replacement of faulty parts, conduct
CLEAR MEMORY and INSPECTION MODES.









339
2-7ON-BOARD DIAGNOSTICS II SYSTEM
10. Diagnostics Chart with Trouble Code

H2M1327
: Does the value change less than 0.12 V by
shaking harness and connector of ECM
while monitoring the value with Subaru
Select Monitor?

Subaru Select Monitor
Designate mode using function key.
Function mode: F45

F45: Fuel level sensor output signal is indicated.
: Repair poor contact in ECM connector.
: Even if MIL lights up, the circuit has returned to a
normal condition at this time. A temporary poor
contact of the connector may be the cause.
NOTE:
In this case, repair the following:

Poor contact in fuel pump connector

Poor contact in combination meter connector

Poor contact in ECM connector

Poor contact in coupling connectors (i3, B99 (LHD only),
B22, B98 (LHD)/B97 (RHD), and R57)
G2M0340
10BP4
CHECK FUEL LEVEL SENSOR.
1) Turn ignition switch to OFF.
2) Remove fuel pump access hole lid located on the right
rear of trunk compartment floor (Sedan) or luggage com-
partment floor (Wagon).
B2M0935
3) Disconnect connector from fuel pump.
4) Measure resistance between connector terminals of
fuel pump.
: Terminals
No. 3—No. 5:
Is the resistance less than 100Ω?
: Go to step10BP5.
: Replace fuel sending unit.
343
2-7ON-BOARD DIAGNOSTICS II SYSTEM
10. Diagnostics Chart with Trouble Code