Subaru Legacy IV (2008 year). Manual - part 631

GD(H6DO)-144

Diagnostic Trouble Code (DTC) Detecting Criteria

GENERAL DESCRIPTION

CQ:DTC P0464 FUEL LEVEL SENSOR CIRCUIT INTERMITTENT

1. OUTLINE OF DIAGNOSIS

Detect the unstable output faults from the fuel level sensor caused by noise. Judge as NG when the max. val-
ue and cumulative value of output voltage variation of the fuel level sensor is larger than the threshold value.

2. ENABLE CONDITION

3. GENERAL DRIVING CYCLE

• Always perform the diagnosis continuously at idle speed.
• Pay attention to the fuel level.

Malfunction Criteria

Threshold Value

Engine speed

t 500 rpm

Elapsed time after starting the engine

t 1 second

Battery voltage

t 10.9 V

Idle switch

Fuel level

t 9.6

2 (2.54 US gal,

2.11 Imp gal)

and

54.4

2 (14.37 US gal,

11.97 Imp gal)

Vehicle speed = 0 km/h (0 MPH)

t 10000 ms

GD(H6DO)-145

Diagnostic Trouble Code (DTC) Detecting Criteria

GENERAL DESCRIPTION

4. DIAGNOSTIC METHOD

Calculate the Max. value (DELFLMAX) and cumulative value (SUMFL) of output voltage variation of fuel level
sensor during 12.2 seconds. Judge it normal when both max. and cumulative values are not over the thresh-
old value. Otherwise, when either of them is over the threshold value, the diagnosis counter counts up. Judge
as NG if the counter indicated 4 time(s).

(A)

12288 ms

(C)

Malfunction

(D)

Normal

(B)

NG at 4 time(s)

Diagnosis condition

Diagnosis timer

(A)

Fuel level sensor
A/D value

Amount of Fuel level
output voltage variation

Diagnosis counter

(B)

Calculate the Max. value (DELFLMAX)
and the cumulative value (SUMFL).

(C)

(D)

EN-05569

GD(H6DO)-146

Diagnostic Trouble Code (DTC) Detecting Criteria

GENERAL DESCRIPTION

• Abnormality Judgement

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

The diagnosis counter does not count up when the following conditions are completed within 12288 ms.

Time Needed for Diagnosis: 12288 ms × 4 time(s)
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: 12288 ms

Judgement Value

Malfunction Criteria

Threshold Value

Integrated times of the condition reaching
follows,

t 4 time(s)

DELFLMAX

t Value from Map

SUMFL

t 25.92 V

At this time,

DELFLMAX: Maximum difference of sen-
sor output for 12288 ms

SUMFL: Integrated value of the sensor
output deviation for12288 ms

Map

Fuel level (

2, US gal, Imp gal)

0, 0, 0

10, 2.64,

2.2

20, 5.28,

4.4

30, 7.93,

6.6

40, 10.57,

8.8

50, 13.21,

60, 15.85,

13.2

Measured voltage (V)

0.27

0.426

0.582

0.738

0.894

Maximum value – Minimum value of
change of tank pressure for 12288 ms

t 0 kPa (0.375031 mmHg,
0 inHg)

Maximum value – Minimum value of bat-
tery voltage for12288 ms

t 0.609 V

Judgement Value

Malfunction Criteria

Threshold Value

DELFLMAX

< Value from Map

SUMFL

< 25.92 V

At this time,

DELFLMAX: Maximum difference of sen-
sor output for 12288 ms

SUMFL: Integrated value of the sensor
output deviation for12288 ms

GD(H6DO)-147

Diagnostic Trouble Code (DTC) Detecting Criteria

GENERAL DESCRIPTION

CR:DTC P0500 VEHICLE SPEED SENSOR “A”

1. OUTLINE OF DIAGNOSIS

Judge as NG when outside of the judgment value.
Judge NG when the received data from ABSCM&H/U is abnormal vehicle speed, and the vehicle speed data
is impossible.

2. COMPONENT DESCRIPTION

Vehicle speed signals are taken in to the ABS control module and hydraulic control unit, and normal/errone-
ous data of the ABS wheel speed sensor is received by CAN communication from the ABS control module
and hydraulic control unit.

3. ENABLE CONDITION

4. GENERAL DRIVING CYCLE

Always perform diagnosis more than 2000 ms after starting the engine.

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: 2500 ms
Malfunction Indicator Light Illumination: Illuminates as soon as a malfunction occurs.

• 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: 2500 ms

Secondary Parameters

Enable Conditions

Battery voltage

t 10.9 V

Elapsed time after engine starting

t 2000 ms

Judgement Value

Malfunction Criteria

Threshold Value

Front ABS wheel speed sensor status

Malfunction

Either of the following is established

Front left wheel speed

t 300 km/h (186.4 MPH)

Front right wheel speed

t 300 km/h (186.4 MPH)

Judgement Value

Malfunction Criteria

Threshold Value

Front left wheel speed

> 0 km/h (0 MPH)

and

< 300 km/h (186.4 MPH)

Front right wheel speed

> 0 km/h (0 MPH)

and

< 300 km/h (186.4 MPH)

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