Subaru Legacy IV (2008 year). Manual - part 593

EN(H6DO)(diag)-345

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

ENGINE (DIAGNOSTICS)

Step

Check

Yes

No

1

CHECK ACCELERATOR PEDAL POSITION 
SENSOR OUTPUT.
1) Turn the ignition switch to ON.
2) Measure the voltage between ECM and 
chassis ground.

Connector & terminal

(B135) No. 23 (+) — Chassis ground (–):
(B135) No. 31 (+) — Chassis ground (–):

Is the difference in measured 
values for the main accelerator 
pedal position sensor signal 
and the sub accelerator pedal 
position sensor signal 0 V?

Go to step 3.

Go to step 2.

2

CHECK ACCELERATOR PEDAL POSITION 
SENSOR OUTPUT.
1) Measure the voltage between accelerator 
pedal position sensor connector and chassis 
ground.

Connector & terminal

(B315) No. 6 (+) — Chassis ground (–):
(B315) No. 3 (+) — Chassis ground (–):

Is the difference in measured 
values for the main accelerator 
pedal position sensor signal 
and the sub accelerator pedal 
position sensor signal 0 V?

Replace the accel-
erator pedal. <Ref. 
to SP(H4SO)-3, 
Accelerator 
Pedal.>

Repair the harness 
and connector.

NOTE:
In this case, repair
the following item:
• Open circuit of
harness between
the ECM and ac-
celerator pedal po-
sition sensor
connector.
• Short circuit to
ground in harness
between ECM and
accelerator pedal
position sensor
connector.
• Poor contact of
coupling connector

3

CHECK HARNESS BETWEEN ECM AND AC-
CELERATOR PEDAL POSITION SENSOR 
CONNECTOR.
Check the resistance of harness between the 
accelerator pedal position sensor connector 
and chassis ground.

Connector & terminal

(B315) No. 5 — Chassis ground:
(B315) No. 2 — Chassis ground:

Is the resistance less than 5 

:? Repair the poor 

contact of ECM 
connector.

Repair the harness 
and connector.

NOTE:
In this case, repair
the following item:
• Open circuit of
harness between
the ECM and ac-
celerator pedal po-
sition sensor
connector.
• Open circuit of
harness between
ECM and engine
ground
• Poor contact in
ECM connector
• Poor contact of
coupling connector

EN(H6DO)(diag)-346

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

ENGINE (DIAGNOSTICS)

EL:DTC P2227 BAROMETRIC PRESSURE CIRCUIT RANGE/PERFORMANCE

DTC DETECTING CONDITION:
• Two consecutive driving cycles with fault
• GENERAL DESCRIPTION <Ref. to GD(H6DO)-211, DTC P2227 BAROMETRIC PRESSURE CIRCUIT
RANGE/PERFORMANCE, Diagnostic Trouble Code (DTC) Detecting Criteria.>

CAUTION:
After repair or replacement of faulty parts, perform Clear Memory Mode <Ref. to EN(H6DO)(diag)-52,
OPERATION, Clear Memory Mode.>, and Inspection Mode <Ref. to EN(H6DO)(diag)-44, PROCEDURE,
Inspection Mode.>.

EM:DTC P2228 BAROMETRIC PRESSURE CIRCUIT LOW

DTC DETECTING CONDITION:
• Immediately at fault recognition
• GENERAL DESCRIPTION <Ref. to GD(H6DO)-212, DTC P2228 BAROMETRIC PRESSURE CIRCUIT
LOW, Diagnostic Trouble Code (DTC) Detecting Criteria.>

CAUTION:
After repair or replacement of faulty parts, perform Clear Memory Mode <Ref. to EN(H6DO)(diag)-52,
OPERATION, Clear Memory Mode.>, and Inspection Mode <Ref. to EN(H6DO)(diag)-44, PROCEDURE,
Inspection Mode.>.

Step

Check

Yes

No

1

CHECK FOR ANY OTHER DTC ON DISPLAY. Is any other DTC displayed?

Check DTC using 
“List of Diagnostic 
Trouble Code 
(DTC)”. <Ref. to 
EN(H6DO)(diag)-
81, List of Diagnos-
tic Trouble Code 
(DTC).>

Replace the ECM. 
<Ref. to 
FU(H6DO)-38, 
Engine Control 
Module (ECM).>

NOTE:
The barometric
pressure sensor is
built into the ECM.

Step

Check

Yes

No

1

CHECK FOR ANY OTHER DTC ON DISPLAY. Is any other DTC displayed?

Check DTC using 
“List of Diagnostic 
Trouble Code 
(DTC)”. <Ref. to 
EN(H6DO)(diag)-
81, List of Diagnos-
tic Trouble Code 
(DTC).>

Replace the ECM. 
<Ref. to 
FU(H6DO)-38, 
Engine Control 
Module (ECM).>

NOTE:
The barometric
pressure sensor is
built into the ECM.

EN(H6DO)(diag)-347

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

ENGINE (DIAGNOSTICS)

EN:DTC P2229 BAROMETRIC PRESSURE CIRCUIT HIGH

DTC DETECTING CONDITION:
• Immediately at fault recognition
• GENERAL DESCRIPTION <Ref. to GD(H6DO)-213, DTC P2229 BAROMETRIC PRESSURE CIRCUIT
HIGH, Diagnostic Trouble Code (DTC) Detecting Criteria.>

CAUTION:
After repair or replacement of faulty parts, perform Clear Memory Mode <Ref. to EN(H6DO)(diag)-52,
OPERATION, Clear Memory Mode.>, and Inspection Mode <Ref. to EN(H6DO)(diag)-44, PROCEDURE,
Inspection Mode.>.

Step

Check

Yes

No

1

CHECK FOR ANY OTHER DTC ON DISPLAY. Is any other DTC displayed?

Check DTC using 
“List of Diagnostic 
Trouble Code 
(DTC)”. <Ref. to 
EN(H6DO)(diag)-
81, List of Diagnos-
tic Trouble Code 
(DTC).>

Replace the ECM. 
<Ref. to 
FU(H6DO)-38, 
Engine Control 
Module (ECM).>

NOTE:
The barometric
pressure sensor is
built into the ECM.

EN(H6DO)(diag)-348

Diagnostic Procedure without Diagnostic Trouble Code (DTC)

ENGINE (DIAGNOSTICS)

21.Diagnostic Procedure without Diagnostic Trouble Code (DTC)

A: CHECK SI-DRIVE (SUBARU INTELLIGENT DRIVE) SYSTEM

DIAGNOSIS:
SI-DRIVE mode will not change.

CAUTION:
Note that the SI-DRIVE system performs the following control when changing modes.
1. When the engine is cold, the low coolant temperature display will light in the multi-information dis-
play meter. In this case, it will not be possible to change to the S# (sports sharp) mode.
2. If the engine is stopped in the S# (sports sharp) mode, it will be in the S (sports) mode when the
engine is restarted.
3. If the engine is stopped in the S (sports) or I (intelligent) mode, then restarted, it will enter the mode
it was on before stopping the engine.
4. If the malfunction indicator light becomes lit while the engine is running, it will enter the S (sports)
mode. In this case, it will not be possible to change to the S# (sports sharp) or I (intelligent) mode.
5. If there is a possible engine coolant or engine oil temperature overheat condition, it will not be
possible to switch to the S# (sports sharp) mode. When driving in the S# (sports sharp) mode, it will
enter the S (sports) mode.