Subaru 2009 IMPREZA Service Manual page 791

Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
AL:DTC P0181 FUEL TEMPERATURE SENSOR "A" CIRCUIT RANGE/
PERFORMANCE
1. OUTLINE OF DIAGNOSIS
Detect faults in the fuel temperature sensor output properties.
Diagnosis is performed in two methods (drift diagnosis and stuck diagnosis). If either is NG, judge as NG. If
both are OK, Judge as OK and clear the NG.
DRIFT DIAGNOSIS
Normally fuel temperature is lower than engine coolant temperature. When the fuel temperature becomes
higher than the engine coolant temperature, the range is considered to be shifted, and judged as NG.
Stuck Diagnosis
As the engine warms up (cumulative amount of intake air after starting is large), if the fuel temperature which
should rise does not, determine as being stuck and NG.
2. COMPONENT DESCRIPTION
(A)
(B)
EN-01700
(A) Resistance value ( ) (B) Fuel temperature °C (°F)
3. ENABLE CONDITIONS
DRIFT DIAGNOSIS
Secondary Parameters Enable Conditions
None
4. GENERAL DRIVING CYCLE
Always perform the diagnosis continuously.
GD(H4SO)-67