Subaru Legacy IV (2008 year). Manual — part 387

EN(H4DOTC)(diag)-369

Diagnostic Procedure without Diagnostic Trouble Code (DTC)

ENGINE (DIAGNOSTICS)

2. WHEN THE SI-DRIVE MODE IS CHANGED, “MODE CHANGE ERROR” APPEARS IN THE
MULTI INFORMATION DISPLAY APPROXIMATELY 5 SECONDS LATER

3. WHEN THE SI-DRIVE MODE IS CHANGED, “MODE CHANGE ERROR” IS NOT DISPLAYED
IN MULTI INFORMATION DISPLAY, AND “S#”, “I”, “S” FLASHES

NOTE:
In this case, there may be a problem outside the SI-DRIVE system.

Step

Check

Yes

No

1

CHECK DTC.

Is DTC displayed?

Check the corre-
sponding DTC
using the “List of
Diagnostic Trouble
Code (DTC)” for
each unit.

Go to step 2.

2

CHECK DISPLAY OF MULTI-INFORMATION
DISPLAY METER.
Check whether there are other errors displayed
other than the “Mode Change Error”.
Examples:
• “Err” is displayed in the external temperature
or fuel consumption displays.
• FUEL gauge, TEMP gauge or ECO gauge
does not move.

Is there other errors displayed
other than the “Mode Change
Error”?

For the diagnostic
procedure, refer to
LAN section. <Ref.
to LAN(diag)-2,
Basic Diagnostic
Procedure.>

Go to step 3.

3

CHECK MULTI-INFORMATION DISPLAY
METER AND ECM.

Is the multi-information display
meter and ECM part numbers
correct?

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

Replace the multi-
information dis-
play meter or ECM
to that of the cor-
rect part number.
<Ref. to IDI-22,
Combination
Meter.> or <Ref. to
FU(H4DOTC)-52,
Engine Control
Module (ECM).>

Step

Check

Yes

No

1

CHECK MALFUNCTION INDICATOR LIGHT.
1) Start the engine.
2) Check whether the malfunction indicator
light is lit or not.

Does the malfunction indicator
light illuminate?

Check the appro-
priate DTC using
the “List of Diag-
nostic Trouble
Code (DTC)”.
<Ref. to
EN(H4DOTC)(diag)
-81, List of Diag-
nostic Trouble
Code (DTC).>

Go to step 2.

2

CHECK ENGINE COOLANT TEMPERATURE
GAUGE.
1) Turn the ignition switch to ON.
2) Check the engine coolant temperature
gauge.

Is it overheating?

Investigate and
repair the cause of
overheating.

Go to step 3.

3

CHECK DISPLAY OF MULTI-INFORMATION
DISPLAY.
1) Turn the ignition switch to ON.
2) Change the SI-DRIVE mode.
3) Check the display of the multi-information
display.

Do the displays “S#”, “I”, “S” of
the multi-information display
flash?

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

Perform test opera-
tion, and check the
malfunction indica-
tor and the coolant
temperature
gauge. If they are
operating normally,
end the diagnosis.

EN(H4DOTC)(diag)-370

General Diagnostic Table

ENGINE (DIAGNOSTICS)

22.General Diagnostic Table

A: INSPECTION

1. ENGINE

NOTE:
Malfunction of parts other than those listed is also possible. <Ref. to ME(H4DOTC)-100, Engine Trouble in
General.>

Symptoms

Problem parts

1. Engine stalls during idling.

1) Electronic throttle control
2) Manifold absolute pressure sensor
3) Mass air flow and intake air temperature sensor
4) Ignition parts (*1)
5) Engine coolant temperature sensor (*2)
6) Crankshaft position sensor (*3)
7) Camshaft position sensor (*3)
8) Fuel injection parts (*4)

2. Rough idling

1) Electronic throttle control
2) Manifold absolute pressure sensor
3) Mass air flow and intake air temperature sensor
4) Engine coolant temperature sensor (*2)
5) Ignition parts (*1)
6) Air intake system (*5)
7) Fuel injection parts (*4)
8) Crankshaft position sensor (*3)
9) Camshaft position sensor (*3)
10) Oxygen sensor
11) Fuel pump and fuel pump relay

3. Engine does not return to idle.

1) Electronic throttle control
2) Engine coolant temperature sensor
3) Manifold absolute pressure sensor
4) Mass air flow sensor

4. Poor acceleration

1) Manifold absolute pressure sensor
2) Mass air flow and intake air temperature sensor
3) Electronic throttle control
4) Fuel injection parts (*4)
5) Fuel pump and fuel pump relay
6) Engine coolant temperature sensor (*2)
7) Crankshaft position sensor (*3)
8) Camshaft position sensor (*3)
9) A/C switch and A/C cut relay
10) Engine torque control signal circuit
11) Ignition parts (*1)

5. Engine stalls, engine sags or hesitates at acceleration.

1) Manifold absolute pressure sensor
2) Mass air flow and intake air temperature sensor
3) Engine coolant temperature sensor (*2)
4) Crankshaft position sensor (*3)
5) Camshaft position sensor (*3)
6) Purge control solenoid valve
7) Fuel injection parts (*4)
8) Fuel pump and fuel pump relay

6. Surging

1) Manifold absolute pressure sensor
2) Mass air flow and intake air temperature sensor
3) Engine coolant temperature sensor (*2)
4) Crankshaft position sensor (*3)
5) Camshaft position sensor (*3)
6) Fuel injection parts (*4)
7) Throttle position sensor
8) Fuel pump and fuel pump relay

EN(H4DOTC)(diag)-371

General Diagnostic Table

ENGINE (DIAGNOSTICS)

*1: Check ignition coil and spark plug.
*2: Indicate the symptom occurring only in cold temperatures.
*3: Ensure the secure installation.
*4: Check fuel injector, fuel pressure regulator and fuel filter.
*5: Inspect air leak in air intake system.

7. Spark knock

1) Manifold absolute pressure sensor
2) Mass air flow and intake air temperature sensor
3) Engine coolant temperature sensor
4) Knock sensor
5) Fuel injection parts (*4)
6) Fuel pump and fuel pump relay

8. After-burn in exhaust system

1) Manifold absolute pressure sensor
2) Mass air flow and intake air temperature sensor
3) Engine coolant temperature sensor (*2)
4) Fuel injection parts (*4)
5) Fuel pump and fuel pump relay

Symptoms

Problem parts

EN(H4DOTC)(diag)-372

General Diagnostic Table

ENGINE (DIAGNOSTICS)