Subaru Impreza 3 / Impreza WRX / Impreza WRX STI. Service manual — part 278

EN(H4DOTC)(diag)-336

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

ENGINE (DIAGNOSTICS)

Step

Check

Yes

CHECK CURRENT DATA.
1) Start the engine.
2) Read the value of «TGV Position Sensor L»
using the Subaru Select Monitor.
NOTE:

For detailed operation procedures, refer to
“READ CURRENT DATA FOR ENGINE”. <Ref.
to EN(H4DOTC)(diag)-40, Subaru Select Moni-
tor.>

Is the value of «TGV Position
Sensor L» 5 V or more?

Go to step

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,
temporary open or
short circuit of har-
ness may be the
cause.

CHECK HARNESS BETWEEN ECM AND
TUMBLE GENERATOR VALVE ASSEMBLY
LH CONNECTOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connector from tumble gen-
erator valve assembly LH.
3) Start the engine.
4) Read the value of «TGV Position Sensor L»
using the Subaru Select Monitor.
NOTE:

For detailed operation procedures, refer to
“READ CURRENT DATA FOR ENGINE”. <Ref.
to EN(H4DOTC)(diag)-40, Subaru Select Moni-
tor.>

Is the value of «TGV Position
Sensor L» 5 V or more?

Repair the short
circuit to power in
harness between
ECM connector
and tumble gener-
ator valve assem-
bly LH connector.

Go to step

CHECK HARNESS BETWEEN ECM AND
TUMBLE GENERATOR VALVE ASSEMBLY
LH CONNECTOR.
1) Turn the ignition switch to OFF.
2) Measure the resistance of harness between
tumble generator valve assembly LH connector
and engine ground.

Connector & terminal

(E51) No. 2 — Engine ground:

Is the resistance less than 5 Ω? Go to step

Repair the harness
and connector.
NOTE:

In this case, repair
the following item:
• Open circuit in
harness between
ECM

connector

and tumble gener-
ator valve assem-
bly LH connector
• Poor contact of
ECM connector
• Poor contact of
coupling connector

CHECK FOR POOR CONTACT.
Check for poor contact of tumble generator
valve assembly LH connector.

Is there poor contact of the tum-
ble generator valve assembly
LH connector?

Repair the poor
contact of tumble
generator valve
assembly LH con-
nector.

Replace the tum-
ble generator valve
assembly LH.
<Ref. to FU(STI)-
48, Tumble Gener-
ator Valve Assem-
bly.> <Ref. to
FU(w/o STI)-48,
Tumble Generator
Valve Assembly.>

EN(H4DOTC)(diag)-337

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

ENGINE (DIAGNOSTICS)

EC:DTC P2088 INTAKE CAMSHAFT POSITION ACTUATOR CONTROL CIRCUIT

LOW (BANK 1)

DTC DETECTING CONDITION:

• Immediately at fault recognition

• GENERAL DESCRIPTION <Ref. to GD(H4DOTC)-234, DTC P2088 INTAKE CAMSHAFT POSITION AC-

TUATOR CONTROL CIRCUIT LOW (BANK 1), Diagnostic Trouble Code (DTC) Detecting Criteria.>

TROUBLE SYMPTOM:

Improper idling
CAUTION:

After servicing or replacing faulty parts, perform Clear Memory Mode <Ref. to EN(H4DOTC)(diag)-63,

OPERATION, Clear Memory Mode.>, and Inspection Mode <Ref. to EN(H4DOTC)(diag)-49, PROCE-

DURE, Inspection Mode.>.

WIRING DIAGRAM:

• Engine electrical system, without SI-DRIVE <Ref. to WI-32, WITHOUT SI-DRIVE, WIRING DIAGRAM,

Engine Electrical System.>

• Engine electrical system, with SI-DRIVE <Ref. to WI-48, WITH SI-DRIVE, WIRING DIAGRAM, Engine

Electrical System.>

ECM

E38

E37

1 2

B134

B21

E38

E37

19 20 21 22 23

24 25

28 29

30 31

B134

15 16 17 18 19 20 21 22

23 24 25 26 27 28 29 30 31 32 33

13 14

9 10

7 8

5 6

3 4

1 2

34 35 36 37 38 39 40 41
42 43

44 45

46 47

48 49 50 51 52 53 54

B21

EN-09254

INTAKE OIL FLOW

CONTROL SOLENOID

VALVE LH

INTAKE OIL FLOW

CONTROL SOLENOID

VALVE RH

EN(H4DOTC)(diag)-338

Diagnostic Procedure with Diagnostic Trouble Code (DTC)

ENGINE (DIAGNOSTICS)

Step

Check

Yes

CHECK HARNESS BETWEEN ECM AND OIL
FLOW CONTROL SOLENOID VALVE RH
CONNECTOR.
1) Turn the ignition switch to OFF.
2) Disconnect the connectors from ECM and
oil flow control solenoid valve RH.
3) Measure the resistance of harness between
ECM connector and oil flow control solenoid
valve RH connector.

Connector & terminal

(B134) No. 34 — (E38) No. 1:
(B134) No. 27 — (E38) No. 2:

Is the resistance less than 1 Ω? Go to step

Repair the harness
and connector.
NOTE:

In this case, repair
the following item:
• Open circuit in
harness between
ECM

connector

and oil flow control
solenoid valve RH
connector
• Poor contact of
coupling connector

CHECK HARNESS BETWEEN ECM AND OIL
FLOW CONTROL SOLENOID VALVE RH
CONNECTOR.
Measure the resistance between ECM connec-
tor and chassis ground.

Connector & terminal

(B134) No. 34 — Chassis ground:
(B134) No. 27 — Chassis ground:

Is the resistance 1 MΩ or
more?

Go to step