Subaru 2009 IMPREZA Service Manual page 879

Diagnostic Trouble Code (DTC) Detecting Criteria
CH:DTC P0852 NEUTRAL SWITCH INPUT CIRCUIT HIGH (MT MODEL)
1. OUTLINE OF DIAGNOSIS
Detect the open or short circuit of neutral SW.
Judge as NG when there is no change in the neutral SW even if the driving shift was applied. (There is neutral
SW ON/OFF inversion from the vehicle speed and engine speed.)
2. ENABLE CONDITIONS
Secondary Parameters
Battery voltage
Starter relay
3. GENERAL DRIVING CYCLE
Perform the diagnosis continuously in 2 seconds after starting the engine.
4. DIAGNOSTIC METHOD
• Abnormality Judgement
Judge NG when the malfunction criteria below are completed determined times or more after the neutral SW
change.
Judgement Value
Malfunction Criteria
Neutral switch signal (while changing
from a to b below)
Driving condition change
a) Engine speed 600 rpm — 900 rpm &
Vehicle speed = 0 km/h (0 MPH)
b) Engine speed 1600 rpm — 2550 rpm
& Vehicle speed 64 km/h (39.8 MPH)
Time Needed for Diagnosis: 3 time(s)
Malfunction Indicator Light Illumination: Illuminates when malfunction occurs in 2 continuous driving cy-
cles.
• Normality Judgement
Judge as OK and clear NG when there is change in the neutral SW.
Judgement Value
Malfunction Criteria
Neutral switch signal (while changing
from a to b below)
Driving condition change
a) Engine speed 600 rpm — 900 rpm &
Vehicle speed = 0 km/h (0 MPH)
b) Engine speed 1600 rpm — 2550 rpm
& Vehicle speed 64 km/h (39.8 MPH)
Time Needed for Diagnosis: Less than 1 second
Enable Conditions
10.9 V
OFF
Threshold Value
HIGH (OFF) contin-
ues.
From a) to b)
Threshold Value
Changes to LOW
(ON).
From a) to b)
GD(H4SO)-155
GENERAL DESCRIPTION