ESP inoperative SUBARU FORESTER 2004 Service Repair Manual

FU(H4SO)-66
FUEL INJECTION (FUEL SYSTEM)
Fuel System Trouble in General
29.Fuel System Trouble in General
A: INSPECTION
NOTE:
 When the vehicle is left unattended for an ex-
tended period of time, water may accumulate in the
fuel tank.
To prevent water condensation.
(1) Top off the fuel tank or drain the fuel com-
pletely.
(2) Drain the water condensation from the fuel
filter.
 Refilling the fuel tank.
Refill the fuel tank while there is still some fuel left in
the tank.
 Protecting the fuel system against freezing and
water condensation.
(3) Cold areas :
In snow-covered areas, mountainous areas, ski-
ing areas, etc. where ambient temperatures
drop below 0°C (32°F) throughout the winter
season, use an anti-freeze solution in the fuel
tank. Refueling will also complement the effect
of anti-freeze solution each time the fuel leveldrops to about one-half. After the winter season,
drain the water which may have accumulated in
the fuel filter and fuel tank in the manner same
as that described under “Affected areas” below.
(4) Affected areas :
When the water condensation is notched in the
fuel filter, drain the water from both the fuel filter
and fuel tank or use a water removing agent (or
anti-freeze solution) in the fuel tank.
 Observe the instructions, notes, etc., indicated
on the label affixed to the anti-freeze solution (wa-
ter removing agent) container before use.
Trouble and possible cause Corrective action
1. Insufficient fuel supply to the injector
1) Fuel pump will not operate.
❍Defective terminal contact.Inspect connections, especially ground, and tighten
securely.
❍Trouble in electromagnetic or electronic circuit parts. Replace fuel pump.
2) Lowering of fuel pump function. Replace fuel pump.
3) Clogged dust or water in the fuel filter. Replace fuel filter, clean or replace fuel tank.
4) Clogged or bent fuel pipe or hose. Clean, correct or replace fuel pipe or hose.
5) Air is mixed in the fuel system. Inspect or retighten each connection part.
6) Clogged or bent breather tube or pipe. Clean, correct or replace air breather tube or pipe.
7) Damaged diaphragm of pressure regulator. Replace.
2. Leakage or blow out fuel
1) Loosened joints of the fuel pipe. Retightening.
2) Cracked fuel pipe, hose and fuel tank. Replace.
3) Defective welding part on the fuel tank. Replace.
4) Defective drain packing of the fuel tank. Replace.
5) Clogged or bent air breather tube or air vent tube.Clean, correct or replace air breather tube or air vent
tube.
3. Gasoline smell inside of compartment
1)Loose joints at air breather tube, air vent tube and fuel filler
pipe.Retightening.
2) Defective packing air tightness on the fuel saucer. Correct or replace packing.
3) Cracked fuel separator. Replace separator.
4) Inoperative fuel pump modulator or circuit. Replace.
4. Defective fuel meter indicator
1) Defective operation of fuel level sensor. Replace.
2) Defective operation of fuel meter. Replace.
5. Noise
1) Large operation noise or vibration of fuel pump. Replace.

FU(H4DOTC)-73
FUEL INJECTION (FUEL SYSTEM)
Fuel System Trouble in General
34.Fuel System Trouble in General
A: INSPECTION
NOTE:
 When the vehicle is left unattended for an ex-
tended period of time, water may accumulate in the
fuel tank.
To prevent water condensation.
(1) Top off the fuel tank or drain the fuel com-
pletely.
(2) Drain the water condensation from the fuel
filter.
 Refilling the fuel tank.
Refill the fuel tank while there is still some fuel left in
the tank.
 Protecting the fuel system against freezing and
water condensation.
Cold areas
In snow-covered areas, mountainous areas, skiing
areas, etc. where ambient temperatures drop be-
low 0°C (32°F) throughout the winter season, use
an anti-freeze solution in the fuel tank. Refueling
will also complement the effect of anti-freeze solu-
tion each time the fuel level drops to about one-half. After the winter season, drain the water which
may have accumulated in the fuel filter and fuel
tank in the manner same as that described under
Affected areas below.
 Affected areas
When the water condensation is notched in the fuel
filter, drain the water from both the fuel filter and
fuel tank or use a water removing agent (or anti-
freeze solution) in the fuel tank.
 Observe the instructions, notes, etc., indicated
on the label affixed to the anti-freeze solution (wa-
ter removing agent) container before use.
Trouble and possible cause Corrective action
1. Insufficient fuel supply to the injector
1) Fuel pump will not operate.
❍Defective terminal contact.Inspect connections, especially ground, and tighten
securely.
❍Trouble in electromagnetic or electronic circuit parts. Replace fuel pump.
2) Lowering of fuel pump function. Replace fuel pump.
3) Clogged dust or water in the fuel filter. Replace fuel filter, clean or replace fuel tank.
4) Clogged or bent fuel pipe or hose. Clean, correct or replace fuel pipe or hose.
5) Air is mixed in the fuel system. Inspect or retighten each connection part.
6) Clogged or bent breather tube or pipe. Clean, correct or replace air breather tube or pipe.
7) Damaged diaphragm of pressure regulator. Replace.
2. Leakage or blow out fuel
1) Loosened joints of the fuel pipe. Retightening.
2) Cracked fuel pipe, hose and fuel tank. Replace.
3) Defective welding part on the fuel tank. Replace.
4) Defective drain packing of the fuel tank. Replace.
5) Clogged or bent air breather tube or air vent tube.Clean, correct or replace air breather tube or air vent
tube.
3. Gasoline smell inside of compartment
1)Loose joints at air breather tube, air vent tube and fuel filler
pipe.Retightening.
2) Defective packing air tightness on the fuel saucer. Correct or replace packing.
3) Cracked fuel separator. Replace separator.
4) Inoperative fuel pump modulator or circuit. Replace.
4. Defective fuel meter indicator
1) Defective operation of fuel level sensor. Replace.
2) Defective operation of fuel meter. Replace.
5. Noise
1) Large operation noise or vibration of fuel pump. Replace.

FU(H4DOTC 2.5)-63
FUEL INJECTION (FUEL SYSTEM)
Fuel System Trouble in General
31.Fuel System Trouble in General
A: INSPECTION
NOTE:
 When the vehicle is left unattended for an extended period of time, water may accumulate in the fuel tank.
To prevent water condensation.
(1) Top off the fuel tank or drain the fuel completely.
(2) Drain the water condensation from the fuel filter.
 Refilling the fuel tank.
Refill the fuel tank while there is still some fuel left in the tank.
 Protecting the fuel system against freezing and water condensation.
(3) Cold areas:
In snow-covered areas, mountainous areas, skiing areas, etc. where ambient temperatures drop below
0°C (32°F) throughout the winter season, use an anti-freeze solution in the cooling system. Refueling will
also complement the effect of anti-freeze solution each time the fuel level drops to about one-half. After
the winter season, drain the water which may have accumulated in the fuel filter and fuel tank in the man-
ner same as that described under “Affected areas” below.
(4) Affected areas:
When the water condensation is notched in the fuel filter, drain the water from both the fuel filter and fuel
tank or use a water removing agent (or anti-freeze solution) in the fuel tank.
 Observe the instructions, notes, etc., indicated on the label affixed to the anti-freeze solution (water remov-
ing agent) container before use.
Trouble and possible cause Corrective action
1. Insufficient fuel supply to the injector
1) Fuel pump will not operate.
❍Defective terminal contact.Inspect connections, especially ground, and tighten
securely.
❍Trouble in electromagnetic or electronic circuit parts. Replace the fuel pump.
2) Lowering of fuel pump function. Replace the fuel pump.
3) Clogged dust or water in the fuel filter. Replace the fuel filter, clean or replace fuel tank.
4) Clogged or bent fuel pipe or hose. Clean, correct or replace the fuel pipe or hose.
5) Air is mixed in the fuel system. Inspect or retighten each connection part.
6) Clogged or bent breather tube or pipe. Clean, correct or replace the air breather tube or pipe.
7) Damaged diaphragm of pressure regulator. Replace.
2. Leakage or blow out fuel
1) Loosened joints of the fuel pipe. Retightening.
2) Cracked fuel pipe, hose and fuel tank. Replace.
3) Defective welding part on the fuel tank. Replace.
4) Defective drain packing of the fuel tank. Replace.
5) Clogged or bent air breather tube or air vent tube.Clean, correct or replace the air breather tube or air vent
tube.
3. Gasoline smell inside of compartment
1)Loose joints at air breather tube, air vent tube and fuel filler
pipe.Retightening.
2) Defective packing air tightness on the fuel saucer. Correct or replace the packing.
3) Cracked fuel separator. Replace the separator.
4) Inoperative fuel pump modulator or circuit. Replace.
4. Defective fuel meter indicator
1) Defective operation of fuel level sensor. Replace.
2) Defective operation of fuel meter. Replace.
5. Noise
1) Large operation noise or vibration of fuel pump. Replace.