DTC P1448 FUEL TANK SENSOR CONTROL VALVE RANGE PERFORMANCE
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DTC P1448 FUEL TANK SENSOR CONTROL VALVE
RANGE PERFORMANCE
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Detect the tank pressure switching solenoid
function abnormality.
The tank pressure sensor is a relative pressure
sensor, which normally compares the pressure with the atmospheric
pressure. The tank pressure switching solenoid is a solenoid, which
shifts the compare space from opening to closed during the EVAP
diagnosis. Detect the malfunction that the compare space remains closed.
(Not judge NG after enable condition completed but assume NG before
enable condition completed.)
Normality Judgment
Judge OK when the fuel tank pressure does
not change (or changes by less than 0.6 kPa (4.5 mmHg, 0.2 inHg))
at atmospheric pressure changing by 0.6 kPa (4.5 mmHg, 0.2 inHg)
or more per 80 seconds.
(A)
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Enable
conditions are completed.
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(F)
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PCV function
reduces the tank pressure.
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(B)
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80 s
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(G)
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Judge OK when the tank pressure does not change
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(C)
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Pressure
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(D)
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Atmospheric
pressure
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(H)
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The tank pressure is relative pressure against atmospheric
pressure.
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(E)
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Tank pressure
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(I)
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Atmospheric
pressure is absolute pressure.
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Abnormality Judgment
Judge NG temporarily when the fuel tank pressure
changes by 0.6 kPa (4.5 mmHg, 0.2 inHg) or more at atmospheric pressure
changing by 0.6 kPa (4.5 mmHg, 0.2 inHg) or more per 80 seconds,
and then judge NG when the previous condition is completed 5 times
in a row.
(A)
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Enable
conditions are completed.
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(F)
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Judge NG temporarily the tank pressure changes once, and then
judge NG the tank pressure changes five times in a row.
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(B)
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80 s
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(C)
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Pressure
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(D)
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Atmospheric
pressure
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(G)
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The tank pressure sensor outputs the valve that is relative
pressure against the compare space 101.3 kPa (760 mmHg, 29.29 inHg)
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(E)
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Tank pressure
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(H)
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Atmospheric
pressure is absolute pressure.
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(A)
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Fuel tank
pressure sensor
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(B)
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Ambient
air
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Secondary
Parameter
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Enable
Condition
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Battery
voltage
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≥ 10.9
V
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Fuel
level
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9 ←→ 51litres(2.38 ←→ 13.3
US gal, 1.98 ←→ 11.2 Imp gal)
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Evaporation
system diagnosis
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Not
in operation
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After
starting the engine
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80
seconds or more
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Fuel tank
pressure
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< −0.67
kPa (−5 mmHg, −0.2 inHg) or > −1.27
kPa (9.5 mmHg, 0.37 inHg)
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Perform the diagnosis continuously when the
fuel tank pressure is large or small in 80 seconds or more after starting
the engine.
Abnormality Judgment
Judge NG when the malfunction criteria below
is completed 5 times.
Judgment
Value
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Malfunction
Criteria
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Threshold
Value
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Atmospheric
air change in 80 seconds
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≥ 0.60
kPa (4.5 mmHg, 0.2 inHg)
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Fuel
tank pressure change in 80 seconds
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≥ 0.60
kPa (4.5 mmHg, 0.2 inHg)
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Fuel level
change
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< 3 litres(0.79
US gal, 0.7 Imp gal)
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Time Needed for Diagnosis:
80
seconds × 5 times
Malfunction Indicator
Light Illumination:
Illuminates when malfunction occurs in
2 continuous driving cycles.
Normality Judgment
Judge OK and clear NG when the malfunction
criteria below is completed.
Judgment
Value
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Malfunction
Criteria
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Threshold
Value
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Atmospheric
air change in 80 seconds
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≥ 0.60
kPa (4.5 mmHg, 0.2 inHg)
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Fuel tank
pressure change in 80 seconds
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< 0.60
kPa (4.5 mmHg, 0.2 inHg)
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•
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When the OK idling cycle was completed 40 times
in a row
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•
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When “Clear Memory” was
performed
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MALFUNCTION
INDICATOR LIGHT CLEAR CONDITION
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•
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When the OK driving cycle was completed 3 times
in a row
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•
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When “Clear Memory” was
performed
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None
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ECM OPERATION
AT DTC SETTING
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Memorize the freeze frame data. (For test
mode $02)
