Subaru Impreza 3 / Impreza WRX / Impreza WRX STI. Manual - part 320

GD(H4DOTC)-32

Diagnostic Trouble Code (DTC) Detecting Criteria

GENERAL DESCRIPTION

V: DTC P0068 MAP/MAF - THROTTLE POSITION CORRELATION

1. OUTLINE OF DIAGNOSIS

Detect problems in the intake manifold pressure sensor output properties.

Judge as NG when the intake air pressure AD value is Low whereas it seemed to be High from the viewpoint

of engine condition, or when it is High whereas it seemed to be Low from the engine condition.

2. COMPONENT DESCRIPTION

3. ENABLE CONDITIONS

4. GENERAL DRIVING CYCLE

Perform the diagnosis continuously after idling.

(A)

Output voltage

(B)

Absolute pressure

 

 

 

 

 

 

 

 

(1)

Connector

(2)

Terminals

(3)

O-ring

Secondary Parameters

Enable Conditions

Engine coolant temperature

≥ 70 °C (158 °F)

EN-01765

(B)

(A)

(2)

(3)

(1)

GD(H4DOTC)-33

Diagnostic Trouble Code (DTC) Detecting Criteria

GENERAL DESCRIPTION

5. DIAGNOSTIC METHOD

• Abnormality Judgment
Judge as NG when Low side or High side becomes NG.

If the duration of time while the following conditions are met is longer than the time indicated, judge as NG.

Time Needed for Diagnosis:

Low side: 5000 ms

High side: 5000 ms

Malfunction Indicator Light Illumination: Illuminates when malfunction occurs in 2 continuous driving cy-

cles.
• Normality Judgment
Judge as OK and clear the NG when both Low side and High side become OK.

If the duration of time while the following conditions are met is longer than the time indicated, judge as OK.

Time Needed for Diagnosis:

Low side: Less than 1 second

High side: Less than 1 second

Judgment Value

Malfunction Criteria

Threshold Value

Low

 

Engine speed

< 2500 rpm

Throttle position

≥ 10 °

Output voltage

< 1 V (Models without SI-DRIVE)
< 0.764 V (Models with SI-DRIVE)

Engine load

> 1.356 g/rev (0.05 oz/rev)

High

 

Engine speed

600 rpm — 900 rpm

Throttle position

< 2.75 °

Output voltage

≥ 2.36 V (Models without SI-DRIVE)

≥ 2.126 V (Models with SI-DRIVE)

Engine load

< 0.4 g/rev (0.01 oz/rev)

Judgment Value

Malfunction Criteria

Threshold Value

Low

 

Engine speed

< 2500 rpm

Throttle position

≥ 10 °

Output voltage

≥ 1 V (Models without SI-DRIVE)

≥ 0.764 V (Models with SI-DRIVE)

Engine load

> 1.356 g/rev (0.05 oz/rev)

High

 

Engine speed

600 rpm — 900 rpm

Throttle position

< 2.75 °

Output voltage

< 2.36 V (Models without SI-DRIVE)
< 2.126 V (Models with SI-DRIVE)

Engine load

< 0.4 g/rev (0.01 oz/rev)

GD(H4DOTC)-34

Diagnostic Trouble Code (DTC) Detecting Criteria

GENERAL DESCRIPTION

W: DTC P0101 MASS OR VOLUME AIR FLOW CIRCUIT RANGE/PERFOR-

MANCE

1. OUTLINE OF DIAGNOSIS

Detect the malfunction of air flow sensor output properties.

Judge as a low side NG when the air flow voltage indicates a small value regardless of running in a state

where the air flow voltage increases. Judge as a high side NG when the air flow voltage indicates a large val-

ue regardless of running in a state where the air flow voltage decreases. Judge air flow sensor property NG

when the Low side or High side becomes NG.

2. COMPONENT DESCRIPTION

3. ENABLE CONDITIONS

4. GENERAL DRIVING CYCLE

Perform the diagnosis continuously after idling.

(A)

Air

 

 

 

 

 

 

 

 

 

 

(1)

Air flow sensor

(3)

Voltage (V)

(4)

Amount of intake air (kg (lb)/s)

(2)

Intake air temperature sensor

 

 

 

 

Secondary Parameters

Enable Conditions

Engine coolant temperature

≥ 70 °C (158 °F)

EN-01766

(3)

(4)

(2)

(1)

(A)

GD(H4DOTC)-35

Diagnostic Trouble Code (DTC) Detecting Criteria

GENERAL DESCRIPTION

5. DIAGNOSTIC METHOD

• Abnormality Judgment
Judge as NG when Low side or High side becomes NG.

If the duration of time while the following conditions are met is longer than the time indicated, judge as NG.

Time Needed for Diagnosis:

Low: 5000 ms

High: 5000 ms

Malfunction Indicator Light Illumination: Illuminates when malfunction occurs in 2 continuous driving cy-

cles.
• Normality Judgment
Judge as OK and clear the NG when both Low side and High side become OK.

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:

Low: Less than 1 second

High: Less than 1 second

Judgment Value

Malfunction Criteria

Threshold Value

Low

 

Output voltage

< 1.5 V

Engine speed

≥ 2500 rpm

Throttle opening angle

≥ 15 °

Intake manifold pressure

≥ 53.3 kPa (400 mmHg, 15.7 inHg)

High (1)

 

Output voltage

≥ 1.95  V

Engine speed

600  rpm — 900  rpm

Throttle opening angle

< 4.1 °

Intake manifold pressure

< 52.7 kPa (395  mmHg, 15.6 inHg)

High (2)

 

Output voltage

≥ 1.70  V

Engine speed

600  rpm — 900  rpm

Throttle opening angle

< 4.1 °

Intake manifold pressure

< 52.7 kPa (395  mmHg, 15.6 inHg)

Fuel system diagnosis

Rich side malfunction

Judgment Value

Malfunction Criteria

Threshold Value

Low

 

Output voltage

≥ 1.5 V

Engine speed

≥ 2500 rpm

Throttle opening angle

≥ 15 °

Intake manifold pressure

≥ 53.3 kPa (400 mmHg, 15.7 inHg)

High

 

Output voltage

< 1.95  V

Engine speed

600  rpm — 900  rpm

Throttle opening angle

< 4.1 °

Intake manifold pressure

< 52.7 kPa (395  mmHg, 15.6 inHg)

Fuel system diagnosis

Rich side normal