Subaru Legacy IV (2008 year). Service manual — part 386

EN(H4DOTC)(diag)-365

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

ENGINE (DIAGNOSTICS)

Step

Check

Yes

No

1

CHECK SECONDARY AIR PIPING PRES-
SURE.
1) Turn the ignition switch to ON.
2) Using the Subaru Select Monitor, read sec-
ondary air piping pressure data, and compare
with the actual atmospheric pressure.

NOTE:
For detailed operation procedure, refer to
“READ CURRENT DATA FOR ENGINE”. <Ref.
to EN(H4DOTC)(diag)-34, Subaru Select Moni-
tor.>

Is the actual difference with
barometric pressure 50 mmHg
(6.7 kPa, 2.0 inHg, 0.97 psig) or
more?

Go to step 2.

Even if DTC is
detected, the cir-
cuit has returned to
a normal condition
at this time. Repro-
duce the failure,
and then perform
the diagnosis
again.

NOTE:
In this case, tem-
porary poor con-
tact of connector
may be the cause.

2

CHECK SECONDARY AIR PUMP.
1) Start the engine and warm up engine until
coolant temperature is higher than 75°C
(167°F).
2) Check whether the secondary air pump is
operating.

Is the secondary air pump oper-
ating?

Go to step 3.

Replace the sec-
ondary air combi-
nation valve LH.
<Ref. to
EC(H4DOTC)-22,
Secondary Air
Combination
Valve.>

3

CHECK HARNESS BETWEEN ECM AND
SECONDARY AIR PUMP RELAY CONNEC-
TOR.
1) Turn the ignition switch to OFF.
2) Remove the secondary air pump relay from
the relay box.
3) Measure the resistance between the sec-
ondary air pump relay connector and engine
ground terminals.

Connector & terminal

(F9) No. 13 — Engine ground:

Is the resistance 1 M

: or

more?

Go to step 4.

Repair the ground
short circuit of har-
ness between
ECM and second-
ary air pump relay
connector.

4

CHECK SECONDARY AIR PUMP RELAY.
Measure the resistance between the secondary
air pump relay terminals.

Terminals

No. 14 — No. 11:

Is the resistance 1 M

: or

more?

Repair the short
circuit of harness
to power supply
between second-
ary air pump relay
and secondary air
pump connector.

Replace the sec-
ondary air pump
relay. <Ref. to
EN(H4DOTC)(diag)
-8, Electrical Com-
ponent Location.>

EN(H4DOTC)(diag)-366

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 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.

EN(H4DOTC)(diag)-367

Diagnostic Procedure without Diagnostic Trouble Code (DTC)

ENGINE (DIAGNOSTICS)

1. EVEN WHEN THE SI-DRIVE MODE IS CHANGED, THE MULTI INFORMATION DISPLAY
DOES NOT CHANGE, AND THE MODE DOES NOT SWITCH

WIRING DIAGRAM:

Step

Check

Yes

No

1

CHECK SI-DRIVE SELECTOR.
1) Disconnect the connector from the multi-
information display meter.
2) Measure the resistance between connec-
tors when the SI-DRIVE selector is operated.

Connector & terminal

(i11) No. 9 — (i11) No. 12:

Does the resistance change as
shown below?
S#: 2.14 — 3.2 k

:

I: 0.8 — 1.2 k

:

S: Less than 10

:

Go to step 2.

Go to step 5.

2

CHECK SI-DRIVE S# SWITCH.
1) Hold down the SI- DRIVE S# switch on the
steering wheel.
2) Measure the resistance of harness between
the multi-information display meter connector
and chassis ground.

Connector & terminal

(i11) No. 8 — Chassis ground:

Is the resistance less than 10

:? Go to step 3.

Go to step 6.

EN-06953

i1

5 6 7 8

2

1

9

4

3

10

24

22

23

25

27

26

28

11 12 13

14 15 16

17 18 19 20 21

C7

1 2 3 4 5

B68

1 2 3 4 5 6 7
8 9 10 11 12 13 14

1 2 3

4 5 6

7 8 9 10 11 12 13 14

B:

i11

A:

i10

3 4 5

6 7 8 9

19 20 21

14 15 16

17 18

1 2

10

12

11

13

22

ST4

2 3 4 5

1

6

COMBINATION METER

i10

A:

i11

B:

A11

A12

B9

B12

i1

B36

9

24

i54

R99

2

1

R43

C1

15

16

B8

3

2

ST1

ST4

B68

12

5

4

3

C7

ROLL
CONNECTOR

SI-DRIVE

SELECTOR

SI-DRIVE S#

SWITCH

I

S#

S

E

4

5

ST5

ST5

2 3 4 5

1

i54

1 2

3 4 5

6 7 8 9 10 11 12

R43

1 2 3 4 5

6 7 8 9 10

11 12

19 20 21

13 14 15 16 17 18

22

EN(H4DOTC)(diag)-368

Diagnostic Procedure without Diagnostic Trouble Code (DTC)

ENGINE (DIAGNOSTICS)

3

CHECK POOR CONTACT.
Check the following items.
• Cracked or improperly connected connector
• Broken connector pin
• Disconnection connector terminal

Is there any abnormal condi-
tion?

Correct the cause
of trouble.

Go to step 4.

4

RECHECK FAULT.
1) Connect all connectors.
2) Change the SI-DRIVE mode.

Is there any abnormal condi-
tion?

Replace the multi-
information dis-
play meter. <Ref.
to IDI-22, Combi-
nation Meter.>

The circuit has
returned to a nor-
mal condition at
this time. Repro-
duce the failure,
and then perform
the diagnosis
again.

NOTE:
In this case, tem-
porary poor con-
tact of connector
may be the cause.

5

CHECK SI-DRIVE SELECTOR HARNESS
AND CONNECTOR.
Check the following items.
• Short or open circuit in the harness
• Improperly connected or loose terminal in the
SI-DRIVE selector connector
• Improperly connected or loose terminal in
coupling connector

Is there any abnormal condi-
tion?

Correct the cause
of trouble.

Go to step 7.

6

CHECK SI-DRIVE S# SWITCH HARNESS
AND CONNECTOR.
Check the following items.
• Short or open circuit in the harness
• Improperly connected or loose terminal in
steering roll connector
• Improperly connected or loose terminal in
coupling connector

Is there any abnormal condi-
tion?

Correct the cause
of trouble.

Go to step 7.

7

RECHECK FAULT.
1) Connect all connectors.
2) Change the SI-DRIVE mode.

Is there any abnormal condi-
tion?

Replace the SI-
DRIVE selector or
SI-DRIVE S#
switch. <Ref. to
FU(H4DOTC)-50,
SI-DRIVE (SUB-
ARU Intelligent
Drive) Selector.>
<Ref. to
FU(H4DOTC)-51,
SI-DRIVE (SUB-
ARU Intelligent
Drive) S# Switch.>

The circuit has
returned to a nor-
mal condition at
this time. Repro-
duce the failure,
and then perform
the diagnosis
again.

NOTE:
In this case, tem-
porary poor con-
tact of connector
may be the cause.

Step

Check

Yes

No