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Subaru Legacy IV (2008 year). Manual - part 429

GD(H4DOTC)-166

Diagnostic Trouble Code (DTC) Detecting Criteria

GENERAL DESCRIPTION

CO:DTC P1152 O2 SENSOR CIRCUIT RANGE/PERFORMANCE (LOW)

(BANK1 SENSOR1)

1. OUTLINE OF DIAGNOSIS

Detect that

O value remains low.

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

(4)

Ceramic heater

(2)

Exhaust gas

(1)

(2)

(4)

(2)

(3)

EN-01693

(C)

(B)

(D)

(A)

GD(H4DOTC)-167

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 70 °C (158 °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

: — 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

–1 — 1

Judgement Value

Malfunction Criteria

Threshold Value

O value

< 0.85

Judgement Value

Malfunction Criteria

Threshold Value

O value

t 0.85

GD(H4DOTC)-168

Diagnostic Trouble Code (DTC) Detecting Criteria

GENERAL DESCRIPTION

CP: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

(4)

Ceramic heater

(2)

Exhaust gas

(1)

(2)

(4)

(2)

(3)

EN-01693

(C)

(B)

(D)

(A)

GD(H4DOTC)-169

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 70 °C (158 °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

: — 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

–1 — 1

Judgement Value

Malfunction Criteria

Threshold Value

O value

> 1.15

Judgement Value

Malfunction Criteria

Threshold Value

O value

d 1.15

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