Subaru Legacy IV (2008 year). Service manual - part 214

GD(H4SO)-158

Diagnostic Trouble Code (DTC) Detecting Criteria

GENERAL DESCRIPTION

CJ:DTC P1153 O2 SENSOR CIRCUIT RANGE/PERFORMANCE (HIGH) 

(BANK1 SENSOR1)

1. OUTLINE OF DIAGNOSIS

Detect that 

O value remains high.

Judge as NG when lambda value is abnormal in accordance with 

O value of front oxygen (A/F) sensor and

running conditions such as vehicle speed, amount of intake air, engine coolant temperature, sub feedback
control, etc.

2. COMPONENT DESCRIPTION

O value = Actual air fuel ratio/Theoretical air fuel ratio
O > 1: Lean
O < 1: Rich

(A)

Electromotive force

(C)

Lean

(D)

Rich

(B)

Air fuel ratio

 

 

(1)

Atmosphere

(3)

ZrO

2

(4)

Ceramic heater

(2)

Exhaust gas

(1)

(2)

(4)

(2)

(3)

EN-01693

(C)

(B)

(D)

(A)

GD(H4SO)-159

Diagnostic Trouble Code (DTC) Detecting Criteria

GENERAL DESCRIPTION

3. ENABLE CONDITION

4. GENERAL DRIVING CYCLE

Perform diagnosis continuously at a constant speed of 20 km/h (12.4 MPH) or more after 60000 ms have
passed since the engine started.

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: 10000 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: Less than 1 second

Secondary Parameters

Enable Conditions

Time needed for all secondary parameters to be in enable 
conditions

t 4096 ms

Battery voltage

t 10.9 V

Barometric pressure

t 75 kPa (563 mmHg, 22.2 inHg)

Rear oxygen sensor sub feedback

Execution

Rear oxygen sensor output voltage – Feedback target voltage

–0.2 V — 0.1 V

or rear oxygen sensor sub feedback compensation coefficient

On Min.

or rear oxygen sensor sub feedback compensation coefficient

On Max.

Elapsed time after starting the engine

t 60000 ms

Engine coolant temperature

t 75 °C (167 °F)

Vehicle speed

t 20 km/h (12.4 MPH)

Amount of intake air

t 6 g/s (0.21 oz/s)

Load change at 180°CA

< 0.02 g/rev (0 oz/rev)

Front oxygen (A/F) sensor impedance

0 

: — 50 :

Learning value of evaporation gas density

< 0.2 

Total time of operating canister purge

t 19.9 s

Targeted lambda value load compensation coefficient

–0.03  — 0.000 

Judgement Value

Malfunction Criteria

Threshold Value

O value

> 1.15 

Judgement Value

Malfunction Criteria

Threshold Value

O value

d 1.15 

GD(H4SO)-160

Diagnostic Trouble Code (DTC) Detecting Criteria

GENERAL DESCRIPTION

CK:DTC P1160 RETURN SPRING FAILURE

1. OUTLINE OF DIAGNOSIS

Judge as NG when the valve is opened more than the default opening angle, but does not move to the close
direction with the motor power stopped.

2. COMPONENT DESCRIPTION

3. ENABLE CONDITION

4. GENERAL DRIVING CYCLE

• Ignition switch ON 

o OFF

• Ignition switch OFF 

o ON (Only after clearing memory)

5. DIAGNOSTIC METHOD

Judge as OK and clear the NG when the malfunction criteria below are met.

Time Needed for Diagnosis: 1880 milliseconds
Malfunction Indicator Light Illumination: Illuminates as soon as a malfunction occurs.

(1)

Opener spring

(4)

Full closed stopper

(7)

DC motor

(2)

Return spring

(5)

Throttle valve

(8)

Main and sub throttle sensor

(3)

Intermediate stopper

(6)

Gear

 

 

Secondary Parameters

Enable Conditions

Motor continuity

OFF

Judgement Value

Malfunction Criteria

Threshold Value

Opening variation after continuity is set 
to OFF

t 2°

EN-01866

S S

(8)

(6)

(7)

(5)

(1)

(3)

(2)

(4)

GD(H4SO)-161

Diagnostic Trouble Code (DTC) Detecting Criteria

GENERAL DESCRIPTION

CL:DTC P1400 FUEL TANK PRESSURE CONTROL SOLENOID VALVE CIRCUIT 

LOW

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 CONDITION

4. GENERAL DRIVING CYCLE

Always perform the diagnosis after starting the engine.

(A)

Barometric 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)