Subaru Legacy IV (2008 year). Manual - part 198

GD(H4SO)-94

Diagnostic Trouble Code (DTC) Detecting Criteria

GENERAL DESCRIPTION

BC:DTC P0341 CAMSHAFT POSITION SENSOR “A” CIRCUIT RANGE/

PERFORMANCE (BANK 1 OR SINGLE SENSOR)

1. OUTLINE OF DIAGNOSIS

Detect the malfunction of camshaft position sensor output property.
Judge as NG when the camshaft line signal input timing is shifted from the crankshaft signal because of tim-
ing belt tooth chip etc.

2. COMPONENT DESCRIPTION

(A)

Camshaft signal

(B)

Crankshaft signal

 

 

(1)

Boss

(3)

Air gap

(5)

Camshaft one revolution (engine 
two revolutions)

(2)

Cam sprocket

(4)

Camshaft position sensor

(A)

(B)

OK

OK

NG

NG

10 CA

#2BTDC10 CA

#4BTDC10 CA

#1BTDC10 CA

30 CA 30 CA

#1BTDC10 CA

#3BTDC10 CA

EN-05542

EN-01782

(1)

(1)

(3)

(4)

(5)

(2)

GD(H4SO)-95

Diagnostic Trouble Code (DTC) Detecting Criteria

GENERAL DESCRIPTION

3. ENABLE CONDITION

4. GENERAL DRIVING CYCLE

Always perform the diagnosis continuously at idle speed.

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: 10 engine revs. engine revs.
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: Two engine revolutions

Secondary Parameters

Enable Conditions

Cylinder number identification

Completed

Battery voltage

t 8 V

Engine speed

550 rpm — 1000 rpm

Engine operation

Idling

Misfire

Not detected

Engine load change during 4 milliseconds

d 12799.8 rpm

Judgement Value

Malfunction Criteria

Threshold Value

Position of camshaft position sensor signal Not between BTDC 

10°CA and BTDC 
80°CA

Judgement Value

Malfunction Criteria

Threshold Value

Position of camshaft position sensor signal Between BTDC 10°CA 

and BTDC 80°CA

GD(H4SO)-96

Diagnostic Trouble Code (DTC) Detecting Criteria

GENERAL DESCRIPTION

BD:DTC P0400 EXHAUST GAS RECIRCULATION FLOW

1. OUTLINE OF DIAGNOSIS

Detect EGR system malfunction.
Intake manifold pressure (negative pressure) is constant because the throttle valve is fully closed during de-
celeration fuel cut. At this time, when the EGR valve is opened/closed, the intake manifold pressure will
change. EGR System OK/NG is judged by the range of this change.

2. COMPONENT DESCRIPTION

(1)

ECM

(4)

CPU

(6)

Main relay

(2)

Detecting circuit

(5)

EGR valve

(7)

Battery power supply

(3)

Switching 

circuit

  

  

EN-02192

( 1 )

( 2 )

( 3 )

( 4 )

( 5 )

( 6 )

( 7 )

GD(H4SO)-97

Diagnostic Trouble Code (DTC) Detecting Criteria

GENERAL DESCRIPTION

3. ENABLE CONDITION

4. GENERAL DRIVING CYCLE

During deceleration fuel cut from 53 km/h (approx. 33 MPH) or more, perform diagnosis once.
Be careful of vehicle speed and engine speed. (Diagnosis will not be completed if the vehicle speed and en-
gine speed conditions become out of specification due to deceleration.)

5. DIAGNOSTIC METHOD

Measure the pressure values when the enable conditions are established, and perform diagnosis by calcu-
lating those results.
1. Label the intake manifold pressure value as PMOF1, which is observed when enable conditions are es-
tablished, and set the EGR target step to 50 steps (nearly full open).
2. Label the intake manifold pressure value as PMON, which is observed after one second has passed since
EGR target step was set to 50 steps (when the enable conditions were established), and set the EGR target
step to 0.
3. Label the intake manifold pressure as PMOF2, which is observed after one second has passed since EGR
target step was set to 0 (after two seconds have passed since the enable conditions were established).

• Abnormality Judgement

Judge as NG when the following conditions are established.

Time Needed for Diagnosis: 1 time
Malfunction Indicator Light Illumination:  Illuminates when malfunction occurs in 2 continuous driving cy-
cles.

Secondary Parameters

Enable Conditions

Elapsed time after starting the engine

t 40 s

Engine coolant temperature

t 75 °C(167 °F)

Engine speed

1200 rpm — 2950 rpm

Intake manifold pressure (absolute pressure)

< 44 kPa (330 mmHg, 13 inHg)

Ambient air temperature

t 5 °C(41 °F)

Throttle position

< 0.25 °

Battery voltage

t 10.9 V

Barometric pressure

t 75 kPa (563 mmHg, 22.2 inHg)

Vehicle speed

t58 km/h (36 MPH)

Fuel shut-off function

In operation

Neutral switch

OFF

After neutral switch ON/OFF change

t Value from Map

No load change (A/C, power steering, lighting, 
rear defogger, heater fan and radiator fan)

t 5000 ms

Map

Engine coolant temperature

°C (°F)

–40

(–40)

–30

(–22)

–20

(–4)

–10

(14)

0

(32)

10

(50)

20

(68)

30

(86)

After neutral switch change

msec

0

0

0

0

0

0

0

0

Engine coolant temperature

°C (°F)

40

(104)

50

(122)

60

(140)

70

(158)

80

(176)

90

(194)

100

(212)

110

(230)

After neutral switch change

msec

0

0

0

0

0

0

0

0

Judgement Value

Malfunction Criteria

Threshold Value

PMON – (PMOF1 + PMOF2)/2

< 2.5 kPa (18.63 mmHg, 
0.7 inHg)