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Home >> Subaru >> 2009 >> Outback i, Standard >> Repair and Diagnosis (Single Page) >> Engine Performance >> System >> Diagnostic Trouble Code (DTC) Detecting Criteria (H4SO) >> Diagnostic Trouble Code (DTC) Detecting Criteria >> DTC P0464 Fuel Level Sensor Circuit Intermittent >> Diagnostic Method
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Diagnostic Method

Calculate the Max. value (DELFLMAX) and cumulative value (SUMFL) of output voltage variation of fuel level sensor during 12.2 seconds. Judge it normal when both max. and cumulative values are not over the threshold value. Otherwise, when either of them is over the threshold value, the diagnosis counter counts up. Judge as NG if the counter indicated 4 time(s).

Fig 1: Fuel Level Sensor Output Voltage Graph
G06334950Courtesy of SUBARU OF AMERICA, INC.

If the duration of time while the following conditions are met is longer than the time indicated, judge as NG.

Judgement Value 

JUDGEMENT VALUE REFERENCE

Malfunction Criteria Threshold Value
Integrated times of the condition reaching follows, ≥ 4 time(s)
DELFLMAX ≥ Value from Map
or  
SUMFL ≥ 25.92 V
At this time,
DELFLMAX: Maximum difference of sensor output for 12288 ms
SUMFL: Integrated value of the sensor output deviation for 12288 ms
 

Map 

FUEL LEVEL REFERENCE

Fuel level ( , US gal, lmp gal) 0, 0, 0 10, 2.64, 2.2 20, 5.28, 4.4 30, 7.93, 6.6 40,10.57, 8.8 50, 13.21, 11 60, 15.85, 13.2
Measured voltage (V) 0.27 0.27 0.426 0.582 0.738 0.894 0.894

The diagnosis counter does not count up when the following conditions are completed within 12288 ms.

VOLTAGE SPECIFICATION

Maximum value - Minimum value of change of tank pressure for 12288 ms ≥ 0 kPa (0.375 mmHg, 0 inHg)
Maximum value - Minimum value of battery voltage for 12288 ms ≥ 0.609 V

Time Needed for Diagnosis:  12288 ms x 4 time(s)

Malfunction Indicator Light Illumination:  Illuminates when malfunction occurs in 2 continuous driving cycles.

Judge as OK and clear the NG if the continuous time while the following conditions are established is more than the predetermined time.

Judgement Value 

JUDGEMENT VALUE REFERENCE

Malfunction Criteria Threshold Value
DELFLMAX < Value from Map
SUMFL < 25.92 V
At this time,
DELFLMAX: Maximum difference of sensor output for 12288 ms
SUMFL: Integrated value of the sensor output deviation for 12288 ms
 

Time Needed for Diagnosis:  12288 ms