Subaru Legacy IV (2008 year). Manual - part 598

GD(H6DO)-12

Diagnostic Trouble Code (DTC) Detecting Criteria

GENERAL DESCRIPTION

B: DTC P0016 CRANKSHAFT POSITION - CAMSHAFT POSITION CORRELATION 

(BANK1)

1. OUTLINE OF DIAGNOSIS

Detect the AVCS system malfunction.
Judge as NG when the timing advance is outside the normal range.

2. COMPONENT DESCRIPTION

3. ENABLE CONDITION

4. GENERAL DRIVING CYCLE

Perform the diagnosis continuously after starting engine and while AVCS is not operating.

(1)

AVCS timing controller

(3)

Engine control module (ECM)

(5)

Oil pressure

(2)

Vane

(4)

Oil flow control solenoid valve

 

 

Secondary Parameters

Enable Conditions

Battery voltage

t 10.9 V

Engine speed

t 500 rpm

Engine coolant temperature

t 50 °C (122 °F)

AVCS control

Not in operation

Target timing advance

0°CA

EN-01852

(3)

(4)

(1)

(5)

(2)

GD(H6DO)-13

Diagnostic Trouble Code (DTC) Detecting Criteria

GENERAL DESCRIPTION

5. DIAGNOSTIC METHOD

Judge as NG when the camshaft sensor input position is not within the normal range.

• 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: 20000 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: 1000 ms

C: DTC P0018 CRANKSHAFT POSITION - CAMSHAFT POSITION CORRELATION 

(BANK2)

1. OUTLINE OF DIAGNOSIS

NOTE:
For the detection standard, refer to DTC P0016. <Ref. to GD(H6DO)-12, DTC P0016 CRANKSHAFT POSI-
TION - CAMSHAFT POSITION CORRELATION (BANK1), Diagnostic Trouble Code (DTC) Detecting Crite-
ria.>

D: DTC P0021 INTAKE CAMSHAFT POSITION - TIMING OVER-ADVANCED OR 

SYSTEM PERFORMANCE (BANK 2)

1. OUTLINE OF DIAGNOSIS

NOTE:
For the detection standard, refer to DTC P0011. <Ref. to GD(H6DO)-10, DTC P0011 INTAKE CAMSHAFT
POSITION - TIMING OVER-ADVANCED OR SYSTEM PERFORMANCE (BANK 1), Diagnostic Trouble
Code (DTC) Detecting Criteria.>

Judgement Value

Malfunction Criteria

Threshold Value

Crankshaft position when camshaft 
position sensor signal is input

< BTDC 22 °CA (Bank 1)
< BTDC 22 °CA (Bank 2)

 or

 

> BTDC 58 °CA (Bank 1)
> BTDC 58 °CA (Bank 2)

Judgement Value

Malfunction Criteria

Threshold Value

Crankshaft position when camshaft 
position sensor signal is input

t BTDC 22 °CA (Bank 1)
t BTDC 22 °CA (Bank 2)

 and

d BTDC 58 °CA (Bank 1)
d BTDC 58 °CA (Bank 2)

GD(H6DO)-14

Diagnostic Trouble Code (DTC) Detecting Criteria

GENERAL DESCRIPTION

E: DTC P0026 INTAKE VALVE CONTROL SOLENOID CIRCUIT RANGE/

PERFORMANCE (BANK 1)

1. OUTLINE OF DIAGNOSIS

Judge as NG with either Low NG or High NG.
A variable valve lift diagnosis oil pressure switch is installed for diagnosis. It is possible to determine whether
the intake valve is in high mode (increase the amount of lift) or in low mode (suppressing the amount of lift)
when the variable valve lift diagnosis oil pressure switch is turned ON or OFF.

• Normal

• Low  NG

When the variable valve lift diagnosis oil pressure switch remains OFF even though the intake valve tried to
enter high mode (oil switching solenoid valve duty is large), this is judged as a Low NG.

• High NG

When the variable valve lift diagnosis oil pressure switch remains ON even though the intake valve tried to
enter low mode (oil switching solenoid valve duty is small), this is judged as a High NG.

Oil switching solenoid valve duty

Intake valve

Variable valve lift diagnosis 

oil pressure switch

Large

High mode

ON

Minimum

Low mode

OFF

GD(H6DO)-15

Diagnostic Trouble Code (DTC) Detecting Criteria

GENERAL DESCRIPTION

2. COMPONENT DESCRIPTION

The variable valve lift system optimizes the intake valve lift by switching between the low lift cam and the high
lift cam according to the engine speed. The amount of intake valve lift is varied by controlling the oil switching
solenoid valve duty according to signals from the ECM.

3. ENABLE CONDITION

(A)

When at low speed

(B)

When at high speed

 

 

(1)

Oil switching solenoid valve

Secondary Parameters

Enable Conditions

Battery voltage

t 10.9 V

After engine starting

t 6000 ms

Engine oil temperature

t 0 °C (32 °F)

Variable valve lift control

Operation

EN-03119

(1)

(B)

(A)