Subaru Impreza 3 / Impreza WRX / Impreza WRX STI. Manual — part 364

GD(H4DOTC)-208

Diagnostic Trouble Code (DTC) Detecting Criteria

GENERAL DESCRIPTION

5. DIAGNOSTIC METHOD

• Abnormality Judgment
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 Judgment
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

Judgment Value

Malfunction Criteria

Threshold Value

Battery voltage

≥ 10.9 V

Elapsed time after starting the engine

≥ 1 s

Terminal output voltage when ECM outputs OFF signal

Low

Judgment Value

Malfunction Criteria

Threshold Value

Battery voltage

≥ 10.9 V

Elapsed time after starting the engine

≥ 1 s

Terminal output voltage when ECM outputs OFF signal

High

GD(H4DOTC)-209

Diagnostic Trouble Code (DTC) Detecting Criteria

GENERAL DESCRIPTION

DU:DTC P1410 SECONDARY AIR INJECTION SYSTEM SWITCHING VALVE

STUCK OPEN

1. OUTLINE OF DIAGNOSIS

Always detect abnormality that both combination valve electromagnetic valve and the reed valve are open

failure.

Calculate the integrated value of Max./Min. value and output voltage deviation of the secondary air delivery

pipe pressure sensor output voltage in a given time after engine start. Judge as NG if the integrated value

and the difference between Max. and Min. values are large.

2. ENABLE CONDITIONS

3. GENERAL DRIVING CYCLE

Perform continuous diagnosis when air flow amount is large during the secondary air pump stop after engine

start.

Secondary Parameters

Enable Conditions

Engine speed

≥ 500 rpm
and
< 10000 rpm

Elapsed time after starting the engine

≥ 9000 ms

After secondary air system stops

≥ 9000 ms

Amount of intake air

≥ 2 g/s (0.07 oz/s)
and
< 400 g/s (14.11 oz/s)

Battery voltage

≥ 10.9 V

Engine load

> 0 g/rev

After fuel cut

≥ 1000 ms

GD(H4DOTC)-210

Diagnostic Trouble Code (DTC) Detecting Criteria

GENERAL DESCRIPTION

4. DIAGNOSTIC METHOD

When both combination valve electromagnetic valve and the reed valve are open failure, the failure appears

as pulses in the secondary air delivery pipe pressure sensor output. Detect abnormality by capturing these

pulses using the following method.
• Abnormality Judgment
Calculate Max./Min. value of the secondary air delivery pipe pressure sensor output voltage and the sum of

the output voltage deviation for the given time. Compare the difference between Max. and Min. values with

threshold value and also compare the sum value with the threshold value. If both values exceed the threshold

value, count up NG counter and then judge as NG if the counter reaches the given times.

Time Needed for Diagnosis: 2000 ms × 20 time(s)

Malfunction Indicator Light Illumination: Illuminates as soon as a malfunction occurs.
• Normality Judgment
Judge as OK and clear NG if neither exceeds the threshold value, or if either of the two exceeds the threshold

value.

Time Needed for Diagnosis: 2000 ms

Judgment Value

Malfunction Criteria

Threshold Value

Pipe inner pressure difference between Max. and Min.

> 0.05 V

Sum of the pipe inner pressure variation value every 4 milliseconds

> 5 V

Barometric pressure variation value

< 26.7 kPa (200 mmHg, 7.9 inHg)

Judgment Value

Malfunction Criteria

Threshold Value

Pipe inner pressure difference between Max. and Min.

≤ 0.05 V

Sum of the pipe inner pressure variation value every 4 milliseconds

≤ 5 V

GD(H4DOTC)-211

Diagnostic Trouble Code (DTC) Detecting Criteria

GENERAL DESCRIPTION

DV:DTC P1420 FUEL TANK PRESSURE CONTROL SOL. VALVE CIRCUIT HIGH

1. OUTLINE OF DIAGNOSIS

Detect the open/short circuit of pressure control solenoid valve.

Judge as NG when ECM output level is different from actual terminal level.

2. COMPONENT DESCRIPTION

3. ENABLE CONDITIONS

4. GENERAL DRIVING CYCLE

Always perform the diagnosis after starting the engine.

(A)

Atmospheric pressure

(B)

Shut-off valve

(C)

To fuel tank

(1)

Filter

(3)

Connector terminal

(5)

Valve

(2)

Coil

(4)

Diaphragm

Secondary Parameters

Enable Conditions

None

EN-01759

(1)

(2)

(3)

(4)

(5)

(A)

(B)

(C)