Subaru 2009 IMPREZA Service Manual page 1739

Diagnostic Trouble Code (DTC) Detecting Criteria
4. 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 thresh-
old 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).
Diagnosis condition
Diagnosis timer
Fuel level sensor
A/D value
Amount of Fuel level
output voltage variation
Diagnosis counter
(A) 12288 ms
(D) Normal
(A)
(C)
(D)
1
0
(B) NG at 4 time(s)
GD(H4DOTC)-151
Calculate the Max. value (DELFLMAX)
and the cumulative value (SUMFL).
4
3
2
(B)
GENERAL DESCRIPTION
6
5
(C) Malfunction
EN-05569