Subaru Legacy IV (2008 year). Service manual - part 217

GD(H4SO)-170

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: 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: 128 ms

Judgement Value

Malfunction Criteria

Threshold Value

Terminal voltage level when ECM out-
puts OFF signal

Low level

or

 

Terminal voltage level when EGR oper-
ates

Low level

Judgement Value

Malfunction Criteria

Threshold Value

Terminal voltage level when ECM out-
puts OFF signal

High level

Terminal voltage level when EGR oper-
ates

High level

GD(H4SO)-171

Diagnostic Trouble Code (DTC) Detecting Criteria

GENERAL DESCRIPTION

CQ:DTC P1493 EGR SOLENOID VALVE SIGNAL #1 CIRCUIT MALFUNCTION 

(HIGH INPUT)

1. OUTLINE OF DIAGNOSIS

• Detects open or short circuit of EGR.
• 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 continuously.

(1)

Engine control module (ECM)

(3)

Detecting circuit

(5)

Battery voltage

(2)

Computer unit (CPU)

(4)

Switch circuit

(6)

Main relay

Secondary Parameters

Enable Conditions

Elapsed time after starting the engine

t 1 second

EGR valve target position

> 0 step

Battery voltage

t 10.9 V

EN-02051

(1)

(2)

(3)

(4)

(5)

(6)

GD(H4SO)-172

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: 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: 128 ms

Judgement Value

Malfunction Criteria

Threshold Value

Terminal voltage level when ECM out-
puts OFF signal

High level

or

 

Terminal voltage level when EGR oper-
ates

High level

Judgement Value

Malfunction Criteria

Threshold Value

Terminal voltage level when ECM out-
puts OFF signal

Low level

Terminal voltage level when EGR oper-
ates

Low level

GD(H4SO)-173

Diagnostic Trouble Code (DTC) Detecting Criteria

GENERAL DESCRIPTION

CR:DTC P1494 EGR SOLENOID VALVE SIGNAL #2 CIRCUIT MALFUNCTION 

(LOW INPUT)

1. OUTLINE OF DIAGNOSIS

NOTE:
For the detection standard, refer to DTC P1492. <Ref. to GD(H4SO)-169, DTC P1492 EGR SOLENOID
VALVE SIGNAL #1 CIRCUIT MALFUNCTION (LOW INPUT), Diagnostic Trouble Code (DTC) Detecting Cri-
teria.>

CS:DTC P1495 EGR SOLENOID VALVE SIGNAL #2 CIRCUIT MALFUNCTION 

(HIGH INPUT)

1. OUTLINE OF DIAGNOSIS

NOTE:
For the detection standard, refer to DTC P1493. <Ref. to GD(H4SO)-171, DTC P1493 EGR SOLENOID
VALVE SIGNAL #1 CIRCUIT MALFUNCTION (HIGH INPUT), Diagnostic Trouble Code (DTC) Detecting
Criteria.>

CT:DTC P1496 EGR SOLENOID VALVE SIGNAL #3 CIRCUIT MALFUNCTION 

(LOW INPUT)

1. OUTLINE OF DIAGNOSIS

NOTE:
For the detection standard, refer to DTC P1492. <Ref. to GD(H4SO)-169, DTC P1492 EGR SOLENOID
VALVE SIGNAL #1 CIRCUIT MALFUNCTION (LOW INPUT), Diagnostic Trouble Code (DTC) Detecting Cri-
teria.>

CU:DTC P1497 EGR SOLENOID VALVE SIGNAL #3 CIRCUIT MALFUNCTION 

(HIGH INPUT)

1. OUTLINE OF DIAGNOSIS

NOTE:
For the detection standard, refer to DTC P1493. <Ref. to GD(H4SO)-171, DTC P1493 EGR SOLENOID
VALVE SIGNAL #1 CIRCUIT MALFUNCTION (HIGH INPUT), Diagnostic Trouble Code (DTC) Detecting
Criteria.>

CV:DTC P1498 EGR SOLENOID VALVE SIGNAL #4 CIRCUIT MALFUNCTION 

(LOW INPUT)

1. OUTLINE OF DIAGNOSIS

NOTE:
For the detection standard, refer to DTC P1492. <Ref. to GD(H4SO)-169, DTC P1492 EGR SOLENOID
VALVE SIGNAL #1 CIRCUIT MALFUNCTION (LOW INPUT), Diagnostic Trouble Code (DTC) Detecting Cri-
teria.>

CW:DTC P1499 EGR SOLENOID VALVE SIGNAL #4 CIRCUIT MALFUNCTION 

(HIGH INPUT)

1. OUTLINE OF DIAGNOSIS

NOTE:
For the detection standard, refer to DTC P1493. <Ref. to GD(H4SO)-171, DTC P1493 EGR SOLENOID
VALVE SIGNAL #1 CIRCUIT MALFUNCTION (HIGH INPUT), Diagnostic Trouble Code (DTC) Detecting
Criteria.>