The document describes the operation of an electric power steering (EPS) system. EPS uses an electric motor controlled by a microcomputer to assist steering instead of a hydraulic pump. This makes steering lighter and more efficient. The key components are a torque sensor, EPS motor, and EPS control module. The torque sensor detects steering torque and direction. The motor provides assist torque based on signals from the control module. The control module regulates motor current based on torque sensor and vehicle speed inputs to operate the motor safely and assist steering.

1. ELECTRICAL POWER STEERING
( EPS )

2. ELECTRIC POWER STEERING
 EPS BEKERJA BERDASARKAN KECEPATAN KENDARAAN DAN
TENAGA PUTAR PENGEMUDI PADA STEERING WHEEL YANG
SELANJUTNYA DIKONVERSIKAN SECARA KELISTRIKAN DAN
DIKONTROL OLEH MIKRO KOMPUTER ( CONTROL MODULE )
 EPS TIDAK LAGI MENGGUNAKAN POWER STEERING OIL
PUMP TETAPI MENGGUNAKAN SEBUAH MOTOR DC YANG
DIKONTROL SECARA ELECTRIC.

3. KELEBIHAN EPS
 Kehilangan tenaga mesin sangat kecil
 Konsumsi bahan bakar lebih irit
 Lebih ringan dan kompak
 Sistem power steering bekerja berdasarkan kecepatan
kendaraan
 Mudah dalam pemeriksaan bila terjadi kerusakan
 Lebih aman

4. 3-1.Lokasi
Komponen
1.EPS warning light
2.Steering column
3.Torque sensor
4.EPS motor
5.EPS motor connector
6.Torque sensor connector
7.Steering gear case assembly
8.EPS control module fuse (30A)
9.ECM
10.EPS control module

5. -Steering system yang baru dikembangkan

6. KOMPONEN UTAMA EPS
 Steering wheel
 Steering column
assy.(motor dan clutch)
 Rack and Pinion
 Power Steering Control
Module (PSCM)
 Vehicle Speed Sensor
(VSS)
 Noise suppressor

7. FUNGSI KOMPONEN
PSCM : 1. Mengontrol arus listrik yang
memutarkan motor berdasar-
kan signal yang masuk.
2. Mengontrol tegangan clutch.
3. Fail safe function.
VSS : Mendeteksi kecepatan kendaraan.
NOISE SUPRESSOR :
Mendeteksi putaran mesin
CLUTCH : Menghubungkan/memutuskan pu-
taran motor dengan gear reduksi.

8. 3-2.Fungsi Komponen
Function
Torque
sensor
It outputs the voltage to EPS control module according to
the steering torque and direction detected by 2 sensors :
main and sub.
EPS
motor
It assists steering operation by generating torque
corresponding to the current supplied by EPS control
module.
-It determines motor current value and direction according
to the torque sensor output voltage and vehicle speed sent
from ECM.
-It detects engine state (running / at a stop) according to
the engine speed signal sent from ECM.
It turns on when the system is abnormal.
Component
Steering gear case
assembly
EPS control module
EPS warning light

9. TORQUE SENSOR
 Mendeteksi kuat puntiran steering wheel
 Mendeteksi arah putaran steering wheel

10. PRINSIP KERJA TORQUE SENSOR
(new swift)
 Apabila steering wheel diputar searah jarum jam
(sjj) maka slider akan bergerak naik
 Apabila steering wheel diputar berlawanan arah jarum
jam (bjj), maka slider akan bergerak
turun

11. 3-3-1.Penjelasan
1.Input shaft
2.Output shaft
3.Torsion bar
4.Torque sensor
4a.Core
4b.Housing
4c.Spring
5.Worm wheel
6.Worm gear
7.Steering rack
8.EPS motor
9.Torque limitter
Front
suspension
frame

12. 3-3-2.Torque
Sensor
L: Lift turning
R: Right turning
N: Neutral position
1.Coil 1
2.Coil 2
3.Core
4.Amplifier
5.Main
6.Sub
7.Upper
8.Lower
T:Torque
V:Output voltage

13. 3-3-4.Manual Stopper
1. Input shaft
2. Output shaft
3. Torsion bar
4. Manual stopper part
5. Maximum torsion angle of torsion bar

14. 3-3-3.EPS motor
1.EPS motor
2.Worm wheel
3.Worm gear
4.Torque limitter
4a. Cover
4b. Spring
4c. Plate
4d. Friction plate
4e. Boss (spline-fitted to worm gear)
4f. Case (fixed to motor armature)
5. Torque on motor axis
5a. Excessive torque (impact torque)
5b. Torque generated by motor
5c. Torque limitter slip zone
6. Temperature
5b

15. 3-4.Detail Kontrol
1. Main fuse box
2. Ignition switch
3. Circuit fuse box
4. “EPS” fuse
5. “IG SIG” fuse
6. “METER” fuse
7. Combination meter
8. “EPS” warning lamp
9. VSS
10. Date link connector
(DLC)
11. ECM
12. P/S control module
13. P/S motor
14. Shield
15. Torque sensor
16. Torque sensor
amplifier
17. To ECM, Air bag
SDM and ABS hydraulic
unit/control module
assembly

16. 3-4.Detail Kontrol (cont.)

17. BAGAN ALIRAN CONTROL
TORQUE SENSOR BATTERY VEHICLE SPEED SENSOR
P/S CM
NOISE SUPPRESSOR MOTOR CLUTCH OUTPUT DTC

18. FAIL SAFE FUNCTION
 Bila terjadi ketidak
normalan pada DTC
dari P/SCM maka
akan menghentikan
bekerjanya: Motor &
Clutch (OFF), dan
kemudi masih dapat
bekerja secara
manual

19. OPERASI P/SCM & LAMP.IND. EPS
A. BILA TIDAK ADA KERUSAKAN
Saat Ign.Switch di ON kan tanpa dilakukan
grounding pd.Diagnostic Switch Terminal, mk
lampu indikator EPS menyala selama 2 detik
kemudian padam.
B. BILA ADA KERUSAKAN
Lampu ind.EPS menyala terus, kerusakan yang
terjadi tersimpan dlm back up memory P/SCM.
Bila Diagn.Sw.Terminal di ground kan mk lampu
indikator EPS berkedip sesuai DTC

20. PROSEDUR MELIHAT DTC
1. Carilah monitor coupler
2. Hubungkan dg kabel antara
term. A dan B pd m.coupler
3. Putar steering wheel ke kiri &
ke kanan dan tarik rem parkir
4. Start mesin
5. Bila tdk ada kerusakan DTC
12 (normal)
6. Bila ada kerusakan pd 2 bag. atau
lebih, DTC akan menunjukkan
mulai dari kode angka terkecil
dst ke angka yg lebih besar.

21. POSISI MONITOR COUPLER / DST

22. MONITOR COUPLER
(DST=Data Swicth Terminal)

23. LAMPU INDIKATOR EPS

24. TABEL DTC