Subaru Legacy IV (2008 year). Service manual — part 411

GD(H4DOTC)-94

Diagnostic Trouble Code (DTC) Detecting Criteria

GENERAL DESCRIPTION

BC:DTC P0410 SECONDARY AIR INJECTION SYSTEM

1. OUTLINE OF DIAGNOSIS

Detect NG judging from secondary air delivery pipe pressure, pulse of secondary air delivery pipe pressure
and secondary air pipe airflow amount.

2. ENABLE CONDITION

3. GENERAL DRIVING CYCLE

Perform diagnosis during secondary air pump operation

Secondary Parameters

Enable Conditions

Pump supply pressure check

Estimate ambient temperature

t 4.4 °C

Battery voltage

t 10.9 V

Barometric pressure

t 75 kPa (563 mmHg,
22.2 inHg)

Engine

In operation

Amount of intake air

t 2 g/s (0.07 oz/s)

Secondary air pump

Operating

Combination valve

Bank open (Except
with both banks
closed)

Combination valve both closed pulse
diagnosis

Estimate ambient temperature

t 4.4 °C

Battery voltage

t 10.9 V

Barometric pressure

t 75 kPa (563 mmHg,
22.2 inHg)

Engine

In operation

Engine load

t 0.2 g/rev (0.01 oz/rev)

After fuel cut

t 1000 ms

Combination valve changeover pres-
sure diagnosis

Estimate ambient temperature

t 4.4 °C

Battery voltage

t 10.9 V

Barometric pressure

t 75 kPa (563 mmHg,
22.2 inHg)

Engine

In operation

Amount of intake air

> 2 g/s (0.07 oz/s)

and

< 25 g/s (0.88 oz/s)

Engine speed

< 4000 rpm

After fuel cut

t 1000 ms

Overflow diagnosis

Estimate ambient temperature

t 4.4 °C

Battery voltage

t 10.9 V

Barometric pressure

t 75 kPa (563 mmHg,
22.2 inHg)

Engine

In operation

GD(H4DOTC)-95

Diagnostic Trouble Code (DTC) Detecting Criteria

GENERAL DESCRIPTION

4. DIAGNOSTIC METHOD

Measure secondary air delivery pipe pressure, pulse of secondary air delivery pipe pressure and secondary
air pipe airflow amount.

(1)

IG

(7)

Diagnosis enable condition

(11)

Right bank all closed pressure
(POR) measurement

(2)

Ne

(8)

Pump supply pressure check
(judgment)

(3)

Secondary air pump operating
status

(12)

Both banks all closed pressure
(PORL) measurement

(9)

Flow amount check (judgment)

(4)

E-COMB valve (right hand) status

(10)

Barometric pressure (Pas) mea-
surement before secondary air
control

(13)

Left bank all closed pressure
(POL) measurement

(5)

E-COMB valve (left hand) status

(6)

Secondary air delivery pipe pres-
sure (psi)

(2)

(7)

(8)

(6)

(12)

(11)

(10)

(13)

(9)

EN-05591

(3)

ON

OFF

(1)

ON

OFF

(4)

OPEN

CLOSE

(5)

OPEN

CLOSE

GD(H4DOTC)-96

Diagnostic Trouble Code (DTC) Detecting Criteria

GENERAL DESCRIPTION

Pump supply pressure check

Perform the system function diagnosis with how much the pressure rises when the secondary air pump is
turned from OFF to ON.
Judge as NG if delivery pipe pressure does not rise though it should when the secondary air pump turns OFF
o ON.
• 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: 1984 ms + 2816 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: 1984 ms + 2816 ms

Combination valve both closed pulse diagnosis

Perform open stuck diagnosis of both combination valves using delivery pipe pressure pulse when both com-
bination valves are closed. Determine which side of valves is stuck open by comparing secondary air flow
amount when RH combination valve is closed with that when LH combination valve is closed.
Calculate voltage pulse of the pump supply pipe pressure when both combination valves are closed. The cal-
culation should be small because there is no pulse from supply pipe pressure with both combination valves
closed. When the calculation is large, determine that either of the combination valves is stuck open.
Determine which side of valves is stuck open by comparing secondary air flow amount when the RH combi-
nation valve is closed with that when the LH combination valve is closed. Air flow amount is larger on the
open stuck valve.
• 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: 4000 ms + 992 ms + 992 ms + 992 ms
Malfunction Indicator Light Illumination: Illuminates when malfunction occurs in 2 continuous driving cy-
cles.

Judgement Value

Malfunction Criteria

Threshold Value

DTC

Secondary air supply pipe pressure
(after barometric pressure compensation)

< 0.9 kPa (7 mmHg,
0.3 inHg)

P0410

Judgement Value

Malfunction Criteria

Threshold Value

DTC

Secondary air supply pipe pressure
(after barometric pressure compensation)

t 0.9 kPa (7 mmHg,
0.3 inHg)

P0410

Judgement Value

Malfunction Criteria

Threshold Value

DTC

Pulse calculation value when both com-
bination valves are closed

> Value of Map 1

P2440

Air flow amount when the right bank is
closed (value from Map 2)

t Air flow amount when
the left bank is closed
(value from Map 3)

Pulse calculation value when both com-
bination valves are closed

> Value of Map 1

P2442

Air flow amount when the left bank is
closed (value from Map 3)

> Air flow amount when
the right bank is closed
(value from Map 2)

GD(H4DOTC)-97

Diagnostic Trouble Code (DTC) Detecting Criteria

GENERAL DESCRIPTION

• 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: 4000 ms + 992 ms + 992 ms + 992 ms

Combination valve changeover pressure diagnosis

Perform the RH combination valve stuck closed diagnosis with the variation of delivery pipe pressure when
the RH combination valve turns closed

o open.

Delivery pipe pressure should vary when the RH combination valve turns closed

o open. When the variation

is small, determine that the RH combination valve is stuck closed.
• 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: 4000 ms + 992 ms + 992 ms + 992 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: 4000 ms + 992 ms + 992 ms + 992 ms
Perform the LH combination valve stuck closed diagnosis with the variation of delivery pipe pressure when
the LH combination valve turns open

o closed.

Delivery pipe pressure should vary when the LH combination valve turns open

o closed. When the variation

is small, determine that the LH combination valve is stuck closed.
• 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: 4000 ms + 992 ms + 992 ms + 992 ms
Malfunction Indicator Light Illumination: Illuminates when malfunction occurs in 2 continuous driving cy-
cles.

Judgement Value

Malfunction Criteria

Threshold Value

DTC

Pulse calculation value when both com-
bination valves are closed

d Value of Map 1

P2440, P2442

Judgement Value

Malfunction Criteria

Threshold Value

DTC

Pressure variation value when the RH
combination valve is switched

< Value of Map 4

P2441

Judgement Value

Malfunction Criteria

Threshold Value

DTC

Pressure variation value when the RH
combination valve is switched

t Value of Map 4

P2441

Judgement Value

Malfunction Criteria

Threshold Value

DTC

Pressure variation value when the LH
combination valve is switched

< Value of Map 5

P2443