Subaru Impreza 3 / Impreza WRX / Impreza WRX STI. Manual - part 122

FU(w/o STI)-15

Throttle Body

FUEL INJECTION (FUEL SYSTEMS)

2. Throttle Body

A: REMOVAL

1) Disconnect the ground cable from battery.

2) Lift up the vehicle.

3) Remove  the  under  cover.  <Ref.  to  EI-28,  RE-

MOVAL, Front Under Cover.>

4) Drain approximately 3.0 L (3.2 US qt, 2.6 Imp qt)

of  coolant.  <Ref.  to  CO(w/o  STI)-13,  DRAINING

OF ENGINE COOLANT, REPLACEMENT, Engine

Coolant.>

5) Remove the intercooler. <Ref. to IN(w/o STI)-12,

REMOVAL, Intercooler.>

6) Disconnect the connectors from the throttle posi-

tion sensor.

7) Remove  the  brake  booster  vacuum  hose  from

the clip (A), and remove the bolts securing the air

bypass pipe to the intake manifold.

8) Remove the bolts securing the PCV pipe assem-

bly to the intake manifold, and remove the intake

duct from the throttle body.

9) Disconnect the engine coolant hose from throttle

body.

10) Remove the throttle body from the intake man-

ifold.

IN-00203

FU-05668

FU-06527

(A)

FU-06528

FU-05669

FU-06529

FU(w/o STI)-16

Throttle Body

FUEL INJECTION (FUEL SYSTEMS)

B: INSTALLATION

Install in the reverse order of removal.
NOTE:

Use new O-rings.
Tightening torque:

8 N·m (0.8 kgf-m, 5.9 ft-lb)

Tightening torque:

T1: 3 N·m (0.3 kgf-m, 2.2 ft-lb)

T2: 6.4 N·m (0.7 kgf-m, 4.7 ft-lb)

Tightening torque:

6.4 N·m (0.7 kgf-m, 4.7 ft-lb)

C: INSPECTION

1. THROTTLE SENSOR INSPECTION 

(METHOD WITH CIRCUIT TESTER)

1) Remove  the  lower  inner  trim  of  passenger’s

side.  <Ref.  to  EI-57,  REMOVAL,  Lower  Inner

Trim.>

2) Turn over the floor mat of passenger’s seat.

3) Remove the protect cover.

4) Remove the nuts and bolts which hold the ECM

to the bracket.

5) Turn the ignition switch to ON. (engine OFF)

FU-06530

T2

T1

FU-06531

FU-06532

FU-03416

FU-03417

FU(w/o STI)-17

Throttle Body

FUEL INJECTION (FUEL SYSTEMS)

6) Measure  the  voltage  between  ECM  connector

terminals.

7) After  inspection,  install  the  related  parts  in  the

reverse order of removal.
Tightening torque:

7.5 N·m (0.8 kgf-m, 5.5 ft-lb)

2. THROTTLE SENSOR INSPECTION 

(METHOD WITH SUBARU SELECT MONI-

TOR)

1) Turn the ignition switch to ON. (engine OFF)

2) Read the throttle opening angle signal and volt-

age of throttle sensor using Subaru Select Monitor.

<Ref. to EN(H4DOTC)(diag)-41, READ CURRENT

DATA FOR ENGINE (NORMAL MODE), OPERA-

TION, Subaru Select Monitor.>

3. OTHER INSPECTIONS

1) Check that the throttle body has no deformation,

cracks or other damages.

2) Check  that  the  engine  coolant  hose  has  no

cracks, damage or loose part.

(A) To ECM connector

Throttle 

sensor

Accelerator 

pedal

Terminal No.

Standard

Main

Not depressed 
(Full closed)

18 (+) and 

29 (–)

Approx. 0.6 V

Depressed 
(Full opened)

Approx. 3.96 V

Sub

Not depressed 
(Full closed)

28 (+) and 

29 (–)

Approx. 1.48 V

Depressed 
(Full opened)

Approx. 4.17 V

Throttle sensor

Throttle opening 

angle signal

Standard

Main

0.0%

Approx. 0.6 V

100.0%

Approx. 3.96 V

Sub

0.0%

Approx. 1.48 V

100.0%

Approx. 4.17 V

FU-04049

5

6

7

8

2

1

9

4

3

10

24

22

23

25

11

12

13

14

15

26

27

28

16

17

18

19

20

21

33

34

29

32

30

31

V

(A)

FU(w/o STI)-18

Intake Manifold

FUEL INJECTION (FUEL SYSTEMS)

3. Intake Manifold

A: REMOVAL

1) Remove the V-belt covers.

2) Collect the refrigerant from A/C system. <Ref. to

AC-19, PROCEDURE, Refrigerant Recovery Pro-

cedure.>

3) Release the fuel pressure. <Ref. to FU(w/o STI)-

65, RELEASING OF FUEL PRESSURE, PROCE-

DURE, Fuel.>

4) Disconnect the ground cable from battery.

5) Open the fuel filler lid and remove the fuel filler

cap.

6) Lift up the vehicle.

7) Remove  the  under  cover.  <Ref.  to  EI-28,  RE-

MOVAL, Front Under Cover.>

8) Drain approximately 3.0 L (3.2 US qt, 2.6 Imp qt)

of  coolant.  <Ref.  to  CO(w/o  STI)-13,  DRAINING

OF ENGINE COOLANT, REPLACEMENT, Engine

Coolant.>

9) Remove the air intake duct and air cleaner case.

<Ref.  to  IN(w/o  STI)-10,  REMOVAL,  Air  Intake

Duct.>  <Ref.  to  IN(w/o  STI)-8,  REMOVAL,  Air

Cleaner Case.>

10) Remove the intercooler. <Ref. to IN(w/o STI)-

12, REMOVAL, Intercooler.>

11) Remove  the  generator.  <Ref.  to  SC(STI)-21,

REMOVAL, Generator.>

12) Remove the coolant filler tank. <Ref. to CO(w/o

STI)-28, REMOVAL, Coolant Filler Tank.>

13) Disconnect  the  A/C  pressure  hoses  from  A/C

compressor. <Ref. to AC-41, REMOVAL, Hose and

Pipe.>

14) Disconnect the brake booster vacuum hose.

15) Remove the brake booster vacuum hose from

the clip (A), and remove the bolts securing the air

bypass pipe to the intake manifold.

16) Remove  the  bolts  securing  the  PCV  pipe  as-

sembly to the intake manifold, and remove the in-

take duct from the throttle body.

17) Disconnect the engine coolant hose from throt-

tle body.

ME-03386

IN-00203

FU-06533

FU-06527

(A)

FU-06528

FU-05669