Subaru Legacy IV (2008 year). Manual - part 432

GD(H4DOTC)-178

Diagnostic Trouble Code (DTC) Detecting Criteria

GENERAL DESCRIPTION

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: 2500 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

Judgement Value

Malfunction Criteria

Threshold Value

Battery voltage

t 10.9 V

Elapsed time after starting the engine

t 1 second

Terminal output voltage when ECM out-
puts ON signal

High

Judgement Value

Malfunction Criteria

Threshold Value

Battery voltage

t 10.9 V

Elapsed time after starting the engine

t 1 second

Terminal output voltage when ECM out-
puts ON signal

Low

GD(H4DOTC)-179

Diagnostic Trouble Code (DTC) Detecting Criteria

GENERAL DESCRIPTION

CV:DTC P1443 VENT CONTROL SOLENOID VALVE FUNCTION PROBLEM

1. OUTLINE OF DIAGNOSIS

Detect the abnormal function (stuck closed) of the drain valve.
Judge as NG when fuel tank pressure is low.

2. COMPONENT DESCRIPTION

3. ENABLE CONDITION

4. GENERAL DRIVING CYCLE

Always perform the diagnosis continuously.

(1)

Bobbin

(8)

Magnetic plate

(14)

Retainer

(2)

Coil

(9)

Shaft

(15)

Diaphragm

(3)

Diode

(10)

Plate

(16)

Movable core

(4)

Stator core

(11)

Valve

(17)

Spring

(5)

End plate

(12)

Housing

(18)

Cover

(6)

Body

(13)

Filter

(19)

O-ring

(7)

Yoke

  

  

Secondary Parameters

Enable Conditions

Drain valve

Open

Battery voltage

t 10.9 V

Barometric pressure

t 75 kPa (563 mmHg, 
22.2 inHg)

Tank pressure when starter is OFF 

o

ON

–0.4 kPa (–3.2 mmHg, 
–0.1 inHg)

 and

 

1.4 kPa (10.7 mmHg, 
0.4 inHg)

EN-02294

( 1 )

( 2 )

( 3 )

( 4 )

( 5 )

( 6 )

( 7 )

( 8 )

( 9 )

(10)

(11)

(12)

(13)

(17)

(14)

(15)

(16)

(18)

(19)

(19)

GD(H4DOTC)-180

Diagnostic Trouble Code (DTC) Detecting Criteria

GENERAL DESCRIPTION

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: 3000 ms
Malfunction Indicator Light Illumination: Illuminates as soon as a malfunction occurs.

• 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

Judgement Value

Malfunction Criteria

Threshold Value

Fuel tank pressure

d –4 kPa (–30 mmHg, 
–1.2 inHg)

Judgement Value

Malfunction Criteria

Threshold Value

Fuel tank pressure

> –4 kPa (–30 mmHg, 
–1.2 inHg)

Cumulative time when all the malfunction 
criteria below are met.

t 30000 ms

Purge control solenoid valve duty

Not = 0

Fuel temperature

–10 °C (14 °F) — 55 °C 
(131 °F)

Intake manifold relative pressure

t –26.7 kPa (–200 mmHg, 
–7.9 inHg)

GD(H4DOTC)-181

Diagnostic Trouble Code (DTC) Detecting Criteria

GENERAL DESCRIPTION

CW:DTC P1491 POSITIVE CRANKCASE VENTILATION (BLOW-BY) FUNCTION 

PROBLEM

1. OUTLINE OF DIAGNOSIS

Detect the blow-by hose release abnormality.
Judge as NG when the diagnosis terminal voltage is high.

2. COMPONENT DESCRIPTION

3. ENABLE CONDITION

4. GENERAL DRIVING CYCLE

Always perform the diagnosis continuously.

(1)

Engine control module (ECM)

(3)

PCV diagnosis connector

(4)

5 V

(2)

Detecting 

circuit

  

  

Secondary Parameters

Enable Conditions

None

EN-01790

E

(1)

(2)

(3)

(4)