Subaru Legacy IV (2008 year). Manual — part 606

GD(H6DO)-44

Diagnostic Trouble Code (DTC) Detecting Criteria

GENERAL DESCRIPTION

AG:DTC P0123 THROTTLE/PEDAL POSITION SENSOR/SWITCH “A” CIRCUIT

HIGH

1. OUTLINE OF DIAGNOSIS

Detect the open or short circuit of throttle position sensor 1.
Judge as NG if out of specification.

2. COMPONENT DESCRIPTION

3. ENABLE CONDITION

4. GENERAL DRIVING CYCLE

Always perform the diagnosis continuously.

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: 24 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: 24 ms

(1)

Throttle position sensor 1 signal

(3)

Throttle position sensor

(4)

Engine control module (ECM)

(2)

Throttle position sensor 2 signal

Secondary Parameters

Enable Conditions

Ignition switch

ON

Battery voltage

t 6 V

Judgement Value

Malfunction criteria

Threshold value

Sensor 1 input voltage

t 4.851 V

Judgement Value

Malfunction criteria

Threshold value

Sensor 1 input voltage

< 4.851 V

EN-01859

(1)

(2)

(3)

(4)

GD(H6DO)-45

Diagnostic Trouble Code (DTC) Detecting Criteria

GENERAL DESCRIPTION

AH:DTC P0125 INSUFFICIENT COOLANT TEMPERATURE FOR CLOSED LOOP

FUEL CONTROL

1. OUTLINE OF DIAGNOSIS

Detect the malfunction of engine coolant temperature output property.
Judge as NG when the engine coolant temperature does not rise in driving conditions where it should.

2. COMPONENT DESCRIPTION

3. ENABLE CONDITION

4. GENERAL DRIVING CYCLE

Perform the diagnosis only once after engine start.

(A)

Resistance value (k

:)

(B)

Temperature °C (°F)

(1)

Connector

(2)

Thermistor element

Secondary Parameters

Enable Conditions

Engine speed

t Value from Map

Battery voltage

t 10.9 V

Map

Engine coolant temperature

°C (°F)

–40 (–40)

110 (230)

Engine speed

rpm

500

500

EN-02917

(A)

(2)

(1)

(B)

GD(H6DO)-46

Diagnostic Trouble Code (DTC) Detecting Criteria

GENERAL DESCRIPTION

5. DIAGNOSTIC METHOD

• Abnormality Judgement

Judge as NG if the criteria below are met.

Timer for diagnosis after engine start
a. Timer stop at fuel cut
b. During the driving conditions except a) above, timer counts up as follows.
64 milliseconds + TWCNT milliseconds (the time of at 64 milliseconds)
TWCNT is defined as follows,
TWCNT = 0 at idle switch ON,
TWCNT show on the following table at idle switch OFF.

Judgement value of timer after engine starting
t = 429523 ms – 28605 ms × Ti
Ti : The lowest coolant temperature after engine start
Time Needed for Diagnosis: Less than 1 second
Malfunction Indicator Light Illumination: Illuminates when malfunction occurs in 2 continuous driving cy-
cles.

• Normality Judgement

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

Time Needed for Diagnosis: Less than 1 second

Judgement Value

Malfunction Criteria

Threshold Value

Engine coolant temperature

< 20 °C (68 °F)

Timer for diagnosis after engine start

t Judgement value of
timer after engine start

Vehicle speed km/h (MPH)

0 (0)

8 (5)

16 (9.9)

24 (14.9)

32 (19.9)

40 (24.9)

48 (29.8)

56 (34.8)

Temperature

°C (°F)

–20 (–4)

0 ms

37.136 ms

74.272 ms

111.41 ms

126.66 ms

141.91 ms

163.59 ms

185.26 ms

–10 (14)

0 ms

27.391 ms

54.782 ms

82.173 ms

99.65 ms

117.13 ms

135.96 ms

154.8 ms

0 (32)

0 ms

17.646 ms

35.292 ms

52.938 ms

72.64 ms

92.341 ms

108.34 ms

124.33 ms

10 (50)

0 ms

7.9012 ms

15.802 ms

23.704 ms

45.63 ms

67.556 ms

80.711 ms

93.867 ms

20 (68)

0 ms

7.9012 ms

15.802 ms

23.704 ms

45.63 ms

67.556 ms

80.711 ms

93.867 ms

Judgement Value

Malfunction Criteria

Threshold Value

Engine coolant temperature

t 20 °C (68 °F)

GD(H6DO)-47

Diagnostic Trouble Code (DTC) Detecting Criteria

GENERAL DESCRIPTION

AI: DTC P0126 INSUFFICIENT ENGINE COOLANT TEMPERATURE FOR STABLE

OPERATION

1. OUTLINE OF DIAGNOSIS

Detect the malfunction of the engine coolant temperature sensor characteristics.
Memorize the engine coolant temperature and fuel temperature at the last engine stop, and use them to
judge as NG when the engine coolant temperature does not decrease when it should.

2. COMPONENT DESCRIPTION

3. ENABLE CONDITION

4. GENERAL DRIVING CYCLE

Perform the diagnosis only once after starting the engine.

(A)

Resistance value (k

:)

(B)

Temperature °C (°F)

(1)

Connector

(2)

Thermistor element

Secondary Parameters

Enable Conditions

Battery voltage

t 10.9 V

Refueling from the last engine stop till
the current engine start

None

Fuel level

t 15

2 (3.96 US gal,

3.3 Imp gal)

Engine coolant temperature at the last
engine stop

t 75 °C (167 °F)

EN-02917

(A)

(2)

(1)

(B)