Subaru Legacy IV (2008 year). Manual - part 426

GD(H4DOTC)-154

Diagnostic Trouble Code (DTC) Detecting Criteria

GENERAL DESCRIPTION

CF:DTC P0604 INTERNAL CONTROL MODULE RANDOM ACCESS MEMORY 

(RAM) ERROR

1. OUTLINE OF DIAGNOSIS

Detect the malfunction of microcomputer (RAM).
When there is a problem in the main CPU normal RAM, or the sub CPU normal RAM, judge as NG. Judge
as OK when both are operating properly.
If it is possible to write data to the whole area of RAM in the initial routine, and is possible to read the same
data, it is judged as OK, and if not, NG.

2. ENABLE CONDITION

Diagnosis with the initial routine.

3. GENERAL DRIVING CYCLE

Perform the diagnosis as soon as the ignition switch is turned to ON.

4. DIAGNOSTIC METHOD

• Abnormality Judgement

Judge as NG when the following conditions are established.

Time Needed for Diagnosis: Less than 1 second
Malfunction Indicator Light Illumination: Illuminates as soon as a malfunction occurs.

• Normality Judgement

Judge as OK and clear the NG if the following conditions are established.

Time Needed for Diagnosis: Less than 1 second

Secondary Parameters

Enable Conditions

None

 

Judgement Value

Malfunction Criteria

Threshold Value

Write the specified value to RAM and 
then read.

The written value 
cannot be read.

Judgement Value

Malfunction Criteria

Threshold Value

Write the specified value to RAM and 
then read.

The written value can 
be read.

GD(H4DOTC)-155

Diagnostic Trouble Code (DTC) Detecting Criteria

GENERAL DESCRIPTION

CG:DTC P0605 INTERNAL CONTROL MODULE READ ONLY MEMORY (ROM) 

ERROR

1. OUTLINE OF DIAGNOSIS

Judge as NG when SUM value of ROM is outside the standard value.

2. ENABLE CONDITION

3. GENERAL DRIVING CYCLE

Always perform the diagnosis continuously.

4. DIAGNOSTIC METHOD

• Abnormality Judgement

Judge as NG when the following conditions are established.

Time Needed for Diagnosis:
• Main CPU: 16 milliseconds × 32 time(s)
• Sub CPU: 16 milliseconds × 2 time(s)
Malfunction Indicator Light Illumination: Illuminates as soon as a malfunction occurs.

• Normality Judgement

Judge as OK and clear the NG if the following conditions are established.

Time Needed for Diagnosis:
• Main CPU: 16 milliseconds × 125 time(s)
• Sub CPU: 16 milliseconds × 2 time(s)

Secondary Parameters

Enable Conditions

Ignition switch

ON

Judgement Value

Malfunction Criteria

Threshold Value

SUM value of ROM

Standard

Judgement Value

Malfunction Criteria

Threshold Value

SUM value of ROM

Standard

GD(H4DOTC)-156

Diagnostic Trouble Code (DTC) Detecting Criteria

GENERAL DESCRIPTION

CH:DTC P0607 THROTTLE CONTROL SYSTEM CIRCUIT RANGE/PERFORMANCE

1. OUTLINE OF DIAGNOSIS

Judge as NG when any one of the followings is established.
(1) When the read value of throttle position sensor 1 signal is mismatched between main CPU and sub CPU.
(2) When the read value of accelerator pedal position sensor 1 signal is mismatched between main CPU and
sub CPU.
(3) When the sub CPU operates abnormally.
(4) When the communication between main CPU 

m o sub CPU is abnormal.

(5) When the input amplifier circuit of throttle position sensor 1 is abnormal.
(6) When the cruise control cannot be canceled correctly.
(7) When the signal of brake SW1 and 2 is mismatched.

2. COMPONENT DESCRIPTION

(1)

Throttle position sensor

(6)

Accelerator pedal position sensor 2

(11)

Amplifier circuit

(2)

Throttle position sensor 1

(7)

Battery

(12)

Engine control module (ECM)

(3)

Throttle position sensor 2

(8)

Stop light

(13)

Sub CPU

(4)

Accelerator pedal position sensor

(9)

Brake switch

(14)

Main CPU

(5)

Accelerator pedal position sensor 1

(10)

I/F circuit

 

 

EN-01862

(1)

(4)

(2)

(3)

(5)

(6)

(7)

(8)

(9)

(12)

(11)

(10)

(10)

(10)

(10)

(13)

(14)

GD(H4DOTC)-157

Diagnostic Trouble Code (DTC) Detecting Criteria

GENERAL DESCRIPTION

3. ENABLE CONDITION

4. GENERAL DRIVING CYCLE

(1) — (4): Always perform the diagnosis continuously.
(5): Always perform the diagnosis continuously when idling.
(6): Perform the diagnosis when the brake pedal is depressed.
(7): Always perform the diagnosis continuously.

5. DIAGNOSTIC METHOD

• Abnormality Judgement
Judge as NG when the following conditions are established.

Time Needed for Diagnosis:
(1): 600 ms
(2): 830 ms
(3): 200 ms
(4): 200 ms
(5): 24 ms
(6): 250 ms
(7): 200 ms
Malfunction Indicator Light Illumination: Illuminates as soon as a malfunction occurs.

Secondary Parameters

Enable Conditions

(1) Ignition switch

ON

(1) Battery voltage

t 6 V

(2) Ignition switch

ON

(2) Battery voltage

t 6 V

(3) Ignition switch

ON

(3) Battery voltage

t 6 V

(4) Ignition switch

ON

(4) Battery voltage

t 6 V

(5) Throttle opening angle

 

(5) Ignition switch

ON

(5) Battery voltage

t 6 V

(6) Brake switch (only with cruise control) ON

(6) Ignition switch

ON

(6) Battery voltage

t 6 V

(7) Ignition switch

ON

(7) Battery voltage

t 6 V

Judgement Value

Malfunction Criteria

Threshold Value

(1) Difference of CPU reading value of 
the throttle position sensor signal

t 0.4058 V

(2) Difference of CPU read value of the 
accelerator pedal position sensor signal

t 0.127542424 V

(3) WD pulse from sub CPU

No WD pulse occur

(4) Communication between CPU

Not possible to com-
municate

(5) |Throttle position sensor 1 opening 
angle — (Throttle position sensor 1 
opening angle after passing amplifier) 1/4|

t 3 °

(6) Cruise control cancel signal at brake 
ON

Cruise control cancel 
signal OFF

(7) Brake switch 1, 2 signal

SW 1 and 2 are not 
matched