ED MDPS - Fiat Solutions

8/9/2019 ED MDPS - Fiat Solutions

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MDPS (TRW)

Chonan Technical Service Training Center



CAN Connection

TPMS

PCM

Trip Computer Monitor

Audio

ESPM

MDPSCM

Cluster

CAN

Bus

Line

SAS Data

DLC



System structure

Introduction

Steering Column

!"oint

MDPS S#ST$MM%&IS

Po'er ead

M%&IS

WR MT*+ &R,T

Steering +ear-o.

C%C,PIT M%D$

CASSIS M%D$

M%&IS

①

②

③

④



Po'er head

Com/onents

To column To !"oint

Worm Wheel

%0Ring

&earing

PC&

Dis1

ight +uide

Dust Cover

&earing

Circle i/

2uill Sha3t Ass*y

Sensor de/loy vie'

ASS*# section vie'

Motor

$C

Worm +ear

Worm Wheel

&earingS/ring

ASS*# e.terior



Po'er head

Com/onents

Main ousing

Anti0Rattle S/ring

Worm Wheel

Sensor Ass*y

$C

Motor Worm Sha3t Assy

&earing

%val Ring 4 Cover



System &loc1 Diagram

Ignition Switch Signal

Engine rpm

Vehicle speed

Engine Load

SAS

Warning information

Output motor

Steering LoadC

AN

Steering wheel torue ! position sensor " #uilt in column



Control logic

System Control

Active

Return

#a'

Dam/ing

Assistance

&oost Curve

Motor

Command5

Tor6ue

Angle

7SS

7SS

Tor6ue

Angle

7SS

▶ Main in/ut signals 3or the control logic

① Steering Wheel Tor6ue

② Steering Wheel Position (Angle)

③ 7ehicle S/eed



Tor6ue sensor /rinci/le

System Control

Angle !toruesensor

$ear #o%Motor

&ac' ! (inion $ear

Sensor A Sensor #

LED #LED A

Output shaft to

motor andrac'

Input shaft from

steering wheel

Input shaft discOutput shaft disc

Lens)Diffuser #Lens)Diffuser A

LA A

LA #

Motor

positionsensor

Linear Arra*

+,- pi%el

.arrow spo'e dis'

wide spo'e dis'

Inde. /oint



ASP (A-solute Steering Position) cali-ration

System Control

When 8

/ MD(S Assm0l* was replaced with new one or used one from the other 1ehicles2

/ MD(S ECM 3T#D4 was replaced with new one or used one from the other 1ehicles2

/ A3ter 'heel alignment ad9ustment:




System Control

o'8

Ignition 'e* O. 3engine off4 and set the front tire and steering wheel on the center 3neutral4

position2

/ 5or lower steering effort6 I$ O.3engine run4 I$ off and on whthin , 7 seconds2∼

+4 Connect the scanner and Enter into the 8AS( cali0ration9 menu on the scanner2




System Control

o'8

74 &otate the steering wheel more than :+-;<3Left and right4 from the center position/ To detect the location of inde% point2

=4 &otate the steering 3left and right4 wheel until the screen in the scanner 0ecomes as 0elow2

That is6 if the inde% point is detected6 the ne%t procedure will 0e followed automaticall*2

Scanner will s'ip this procedure if the

inde% point alread* detected >




System Control

o'8

?4 Set the front tire and steering wheel on the neutral position 3:,<4 and press enter 'e* in the

scanner2 2

@4 (ress the esc 'e* and mo1e to the current data in order to confirm the cali0ration status2

8Detect9 or 8.ot detect9"

E1er* I$ off ! on6 this 1alue will show8detect9 or 8not detect9 depending on the

steering wheel position2 #ut it will get

8detect9 naturall* as the steering wheel is

rotated more than +-;< while dri1ing2 38not

detect9 does not mean the cali0ration fault24

CAL!I.DE" Cali0ration is OB andInde% was found2




System Control

o'8

4 5inall* chec' the s*stem rotating the steering wheel and also DTC must 0e chec'ed2 If *ou

ha1e following DTC after AS( cali0ration6 it means that the steering wheel neutral position was

excessively out of specification 3step 8+94 and *ou ha1e to tr* again from the first step2

After DTC detection6 the angle 1alue will 0e fi%ed 0* ero2

Angle Sensor 5ault




System Control

What ha//en i3 it is not done8

+4 In case of replacement with new part

/ Motor assist is a1aila0le 0ut warning lamp will 0lin' and acti1e return 3on/center control4 will

stop2

,4 In case of replacement with used part

/ Motor assist is a1aila0le and warning lamp will not turn on2 Acti1e return 3on/center control4 will

stop2

What ha//en i3 it 'as done 'ith 'rong 'ay8 (im/ro/er steering 'heel center /osition)

/ ou ma* ha1e DTC 3C+,?F4 without warning lamp on2 Gowe1er6 the motor assist is a1aila0le

0ut the acti1e return 3on/center control4 will stop2



In/ut 4 %ut/ut

System Control

+ , -

@ ? = 7



Po'er su//ly 4 Relay

System Control

Motor rela* 30uilt in motor4

ECM rela* 30uilt in ECM4

/ E1er* ignition off from engine running6 the rela* will sound 3off4 after , 7 seconds2∼

/ Gowe1er6 if *ou turn the ignition on 0efore , 7 seconds6 the motor assist is a1aila0le under the∼

ignition on condition e1en though the engine is not running2





nderstanding o3 service data

Diagnosis

Compensation

1alue

/ Stopped

/ Cran'ing

/ &unning



;ailsa3e 3or vehicle s/eed signal 3ault

Diagnosis

/ The 1ehicle speed signal comes from ($/# in A)T through (CM3or TCM4 and CA.2 3.on/O#D onl*4

/ Warning lamp O556 .o DTC and Motor O. 3Default 1ehicle speed is =;'m)h4

.ormal condition ($/# open circuit



;ailsa3e 3or I+N< signal 3ault

Diagnosis

/ I$+ signal is used to detect the engine status 3not for the MD(S ECM s*stem power4

;ailsa3e 3or engine s/eed signal 3ault

5or e%ample6 disconnect the CB( sensor while dri1ing and confirm the s*mptom2

/ Warning lamp O. 3I$ On condition46

/ .o DTC

/ Motor assist O. for 7; seconds and turn off for the safet*2

Di i



;ailsa3e 3or CAN 3ault

Diagnosis

%ne or t'o CAN lines (igh or o') are o/en!short to ground circuit %R &oth CAN lines (igh 4 o') are shorted circuit each other

+4 Warning lamp turns on immediatel*2 3while dri1ing or I$ on 0efore engine starting4

,4 Motor assists the steering under the ignition on condition2 3engine running or not4

74 Motor assists the steering for a0out + minute under the ignition off condition2

3#ecause cannot identif* the engine is running or not4

=4 &ele1ant DTC for CA. is stored2 3C+@++ CA. Timeout EMS4

/ Must clear DTC with scanner2 3.ot erased automaticall* e1en though the fault is disappeared4

?4 .ot possi0le to communicate with the scanner2



Di i



7arient coding

Diagnosis

De3ault

Documents

ED MDPS - Fiat Solutions