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