Subaru IMPREZA GD 2007 Series Manual page 1959

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Diagnostic Trouble Code (DTC) Detecting Criteria
GENERAL DESCRIPTION
BZ:DTC P0483 FAN RATIONALITY CHECK
1. OUTLINE OF DIAGNOSIS
Detect the function abnormality of the radiator fan.
Judge as NG when the engine coolant temperature slowly decreases even when the radiator fan is rotating.
2. ENABLE CONDITION
Diagnostic enable condition is established if the radiator fan changes from OFF → ON when all of the con-
ditions below are met.
When one of the conditions below is not met, the diagnostic enable condition is not established.
Secondary Parameters
Engine speed
Idle switch
Vehicle speed
Battery voltage
3. GENERAL DRIVING CYCLE
Always perform the diagnosis continuously when idling.
4. DIAGNOSTIC METHOD
Abnormality Judgment
Judge as NG when the continuous time of meeting the malfunction criteria below becomes 5 minutes or
more.
Judgment Value
Malfunction Criteria
Engine coolant temperature
Radiator fan signal change
Engine coolant temperature
Time Needed for Diagnosis: 5 minutes
Malfunction Indicator Light Illumination: Illuminates when malfunction occurs in two continuous driving
cycles.
Normality Judgment
Judge as OK and clear the NG when the malfunction criteria below are met.
Judgment Value
Malfunction Criteria
Radiator fan signal change
Engine coolant temperature
5. DTC CLEAR CONDITION
• When the OK idling cycle is completed 40 times in a row
• When "Clear Memory" is performed
6. MALFUNCTION INDICATOR LIGHT CLEAR CONDITIONS
• When the OK driving cycle is completed three times in a row
• When "Clear Memory" is performed
7. FAIL SAFE
None
8. ECM OPERATION AT DTC SETTING
Memorize the freeze frame data. (For test mode $02)
Enable Conditions
550 — 950 rpm
ON
0 km/h (0 MPH)
≥ 10.9 V
Threshold Value
≥ 95°C (203°F)
OFF to ON
Does not decrease
Threshold Value
OFF to ON
Decreases
GD(H4DOTC)-168