Subaru Legacy IV (2008 year). Service manual - part 206

GD(H4SO)-126

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: 15000 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

BL:DTC P0456 EVAPORATIVE EMISSION CONTROL SYSTEM LEAK DETECTED 

(VERY SMALL LEAK)

1. OUTLINE OF DIAGNOSIS

NOTE:
For the detection standard, refer to DTC P0442. <Ref. to GD(H4SO)-101, DTC P0442 EVAPORATIVE
EMISSION CONTROL SYSTEM LEAK DETECTED (SMALL LEAK), Diagnostic Trouble Code (DTC) De-
tecting Criteria.>

BM:DTC P0457 EVAPORATIVE EMISSION CONTROL SYSTEM LEAK DETECTED 

(FUEL CAP LOOSE/OFF)

1. OUTLINE OF DIAGNOSIS

NOTE:
For the detection standard, refer to DTC P0442. <Ref. to GD(H4SO)-101, DTC P0442 EVAPORATIVE
EMISSION CONTROL SYSTEM LEAK DETECTED (SMALL LEAK), Diagnostic Trouble Code (DTC) De-
tecting Criteria.>

Judgement Value

Malfunction Criteria

Threshold Value

Fuel tank pressure

t 7.9 kPa (59.6 mmHg, 
2.3 inHg)

Fuel temperature

< 35 °C (95 °F)

Barometric pressure

t 75 kPa (563 mmHg, 
22.2 inHg)

Judgement Value

Malfunction Criteria

Threshold Value

Fuel tank pressure

< 7.9 kPa (59.6 mmHg, 
2.3 inHg)

GD(H4SO)-127

Diagnostic Trouble Code (DTC) Detecting Criteria

GENERAL DESCRIPTION

BN:DTC P0458 EVAPORATIVE EMISSION SYSTEM PURGE CONTROL VALVE 

CIRCUIT LOW

1. OUTLINE OF DIAGNOSIS

Detect open or short circuit of the purge control solenoid valve.
Judge as NG when the ECM output level differs from the actual terminal level.

2. COMPONENT DESCRIPTION

3. ENABLE CONDITION

4. GENERAL DRIVING CYCLE

Always perform the diagnosis after starting the engine.

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 cycles.

• 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

(A)

To canister

(B)

To intake manifold

 

 

Secondary Parameters

Enable Conditions

Battery voltage

t 10.9 V

Elapsed time after starting the engine

t 1 second

Judgement Value

Malfunction Criteria

Threshold Value

Duty ratio of “ON”

< 0.75 

Terminal output voltage

Low

Judgement Value

Malfunction Criteria

Threshold Value

Terminal output voltage

High

(A)

(B)

EN-02197

GD(H4SO)-128

Diagnostic Trouble Code (DTC) Detecting Criteria

GENERAL DESCRIPTION

BO:DTC P0459 EVAPORATIVE EMISSION SYSTEM PURGE CONTROL VALVE 

CIRCUIT HIGH

1. OUTLINE OF DIAGNOSIS

Detect open or short circuit of the purge control solenoid valve.
Judge as NG when the ECM output level differs from the actual terminal level.

2. COMPONENT DESCRIPTION

3. ENABLE CONDITION

4. GENERAL DRIVING CYCLE

Always perform the diagnosis after starting the engine.

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 cycles.

• 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

(A)

To canister

(B)

To intake manifold

 

 

Secondary Parameters

Enable Conditions

Battery voltage

t 10.9 V

Elapsed time after starting the engine

t 1 second

Judgement Value

Malfunction Criteria

Threshold Value

Duty ratio of “ON”

t 0.25 

Terminal output voltage

High

Judgement Value

Malfunction Criteria

Threshold Value

Terminal output voltage

Low

(A)

(B)

EN-02197

GD(H4SO)-129

Diagnostic Trouble Code (DTC) Detecting Criteria

GENERAL DESCRIPTION

BP:DTC P0461 FUEL LEVEL SENSOR “A” CIRCUIT RANGE/PERFORMANCE

1. OUTLINE OF DIAGNOSIS

Detect malfunctions of the fuel level sensor output property.
If the fuel level does not vary in a particular driving condition / engine condition where it should, judge as NG.

2. COMPONENT DESCRIPTION

3. ENABLE CONDITION

4. GENERAL DRIVING CYCLE

Always perform the diagnosis continuously.

(A)

Fuel level

(B)

Resistance

 

 

Secondary Parameters

Enable Conditions

None

 

EN-01734

0

(B)

(A)