Subaru 2009 IMPREZA Service Manual page 1753

Diagnostic Trouble Code (DTC) Detecting Criteria
CI: DTC P0851 PARK/NEUTRAL SWITCH INPUT CIRCUIT LOW (AT MODEL)
1. OUTLINE OF DIAGNOSIS
Detect the open or short circuit of neutral SW.
Judge as NG when the neutral terminal input in ECM differs from the received data from TCM.
2. ENABLE CONDITION
Secondary Parameters
Battery voltage
Starter relay
3. GENERAL DRIVING CYCLE
Perform the diagnosis continuously after two seconds have passed since the engine started.
4. DIAGNOSTIC METHOD
• Abnormality Judgement
If the duration of time while the following conditions are met is longer than the time indicated, judge as NG.
Judgement Value
Malfunction Criteria
Neutral switch signal in ECM when "P"/
"N" range in TCM are "OFF" and when
the other switches are "ON"
Time Needed for Diagnosis: 100 time(s)
Malfunction Indicator Light Illumination: Illuminates when malfunction occurs in 2 continuous driving cy-
cles.
• Normality Judgement
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
Malfunction Criteria
Neutral switch signal in ECM when "P"/
"N" range in TCM are "OFF" and when
the other switches are "ON"
Time Needed for Diagnosis: Less than 1 second
Enable Conditions
10.9 V
OFF
Threshold Value
LOW (ON)
Threshold Value
HIGH (OFF)
GD(H4DOTC)-165
GENERAL DESCRIPTION