Subaru Legacy IV (2008 year). Manual - part 213

GD(H4SO)-154

Diagnostic Trouble Code (DTC) Detecting Criteria

GENERAL DESCRIPTION

CG:DTC P0852 PARK/NEUTRAL SWITCH INPUT CIRCUIT HIGH (AT MODEL)

1. OUTLINE OF DIAGNOSIS

Judge the open or short circuit of the neutral SW.
Judge as NG when the ECM neutral terminal input differs from the reception data from TCM.

2. ENABLE CONDITION

3. GENERAL DRIVING CYCLE

Perform the diagnosis continuously in 2 seconds after starting the engine.

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.

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.

Time Needed for Diagnosis: Less than 1 second

Secondary Parameters

Enable Conditions

Battery voltage

t 10.9 V

Starter relay

OFF

Judgement Value

Malfunction Criteria

Threshold Value

Neutral switch signal in ECM when “P”/
“N” range in TCM are “ON” and when the 
other switches are “OFF”

HIGH (OFF)

Judgement Value

Malfunction Criteria

Threshold Value

Neutral switch signal in ECM when “P”/
“N” range in TCM are “ON” and when the 
other switches are “OFF”

LOW (ON)

GD(H4SO)-155

Diagnostic Trouble Code (DTC) Detecting Criteria

GENERAL DESCRIPTION

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 CONDITION

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.

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.

Time Needed for Diagnosis: Less than 1 second

Secondary Parameters

Enable Conditions

Battery voltage

t 10.9 V

Starter relay

OFF

Judgement Value

Malfunction Criteria

Threshold Value

Neutral switch signal (while changing 
from a to b below)

HIGH (OFF) continues.

Driving condition change

From a) to b)

a) Engine speed 600 rpm — 900 rpm & 
Vehicle speed = 0 km/h (0 MPH)

b) Engine speed 1600 rpm — 900 rpm & 
Vehicle speed 

t 0 km/h (0 MPH)

Judgement Value

Malfunction Criteria

Threshold Value

Neutral switch signal (while changing 
from a to b below)

Changes to LOW 
(ON).

Driving condition change

From a) to b)

a) Engine speed 600 rpm — 900 rpm & 
Vehicle speed = 0 km/h (0 MPH)

b) Engine speed 1600 rpm — 900 rpm & 
Vehicle speed 

t 0 km/h (0 MPH)

GD(H4SO)-156

Diagnostic Trouble Code (DTC) Detecting Criteria

GENERAL DESCRIPTION

CI: DTC P1152 O2 SENSOR CIRCUIT RANGE/PERFORMANCE (LOW) 

(BANK1 SENSOR1)

1. OUTLINE OF DIAGNOSIS

Detect that 

O value remains low.

Judge as NG when lambda value is abnormal in accordance with 

O value of front oxygen (A/F) sensor and

running conditions such as vehicle speed, amount of intake air, engine coolant temperature, sub feedback
control, etc.

2. COMPONENT DESCRIPTION

O value = Actual air fuel ratio/Theoretical air fuel ratio
O > 1: Lean
O < 1: Rich

(A)

Electromotive force

(C)

Lean

(D)

Rich

(B)

Air fuel ratio

 

 

(1)

Atmosphere

(3)

ZrO

2

(4)

Ceramic heater

(2)

Exhaust gas

(1)

(2)

(4)

(2)

(3)

EN-01693

(C)

(B)

(D)

(A)

GD(H4SO)-157

Diagnostic Trouble Code (DTC) Detecting Criteria

GENERAL DESCRIPTION

3. ENABLE CONDITION

4. GENERAL DRIVING CYCLE

Perform diagnosis continuously at a constant speed of 20 km/h (12.4 MPH) or more after 60000 ms have
passed since the engine started.

5. DIAGNOSTIC METHOD

• Abnormality Judgement

If the duration of time while the following conditions are met is longer than the time indicated, judge as NG.

Time Needed for Diagnosis: 10000 ms
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.

Time Needed for Diagnosis: Less than 1 second

Secondary Parameters

Enable Conditions

Time needed for all secondary parameters to be in enable 
conditions

t 4096 ms

Battery voltage

t 10.9 V

Barometric pressure

t 75 kPa (563 mmHg, 22.2 inHg)

Rear oxygen sensor sub feedback

Execution

Rear oxygen sensor output voltage – Feedback target voltage

–0.2 V — 0.1 V

or rear oxygen sensor sub feedback compensation coefficient

On Min.

or rear oxygen sensor sub feedback compensation coefficient

On Max.

Elapsed time after starting the engine

t 60000 ms

Engine coolant temperature

t 75 °C (167 °F)

Vehicle speed

t 20 km/h (12.4 MPH)

Amount of intake air

t 6 g/s (0.21 oz/s)

Load change at 180°CA

< 0.02 g/rev (0 oz/rev)

Front oxygen (A/F) sensor impedance

0 

: — 50 :

Learning value of evaporation gas density

< 0.2 

Total time of operating canister purge

t 19.9 s

Targeted lambda value load compensation coefficient

–0.03  — 0.000 

Judgement Value

Malfunction Criteria

Threshold Value

O value

< 0.85 

Judgement Value

Malfunction Criteria

Threshold Value

O value

t 0.85