Infiniti F50. Manual - part 746

SCS-1

SUSPENSION CONTROL SYSTEM

E  SUSPENSION

CONTENTS

C

D

F

G

H

I

J

K

L

M

SECTION 

A

B

SCS

SUSPENSION CONTROL SYSTEM

TROUBLE DIAGNOSIS FOR ACTIVE DAMPER 
SUSPENSION ............................................................. 2

Precautions .............................................................. 2

PRELIMINARY CHECK  ........................................ 2

Fail-Safe ................................................................... 2

FAIL-SAFE FUNCTIONS  ...................................... 2
FAIL-SAFE ITEMS  ................................................ 2

Active Damper Suspension Configuration  ............... 3

SYSTEM COMPONENTS ..................................... 3
SCHEMATIC ......................................................... 4
CONTROL UNIT INPUT/OUTPUT SIGNAL 
STANDARD ......................................................... 14

CONSULT-II Inspection Procedure  ........................ 15

SELF-DIAGNOSIS PROCEDURE  ...................... 15
DATA MONITOR PROCEDURE  ......................... 16
DATA MONITOR MODE  ..................................... 16

ACTIVE TEST PROCEDURE  ............................. 17

Self-Diagnosis ........................................................ 19

FUNCTION .......................................................... 19
SELF-DIAGNOSTICS PROCEDURE .................. 19
HOW TO READ SELF-DIAGNOSTIC RESULTS ... 19
MALFUNCTION CODE/SYMPTOM CHART ....... 20
HOW TO ERASE SELF-DIAGNOSTIC 
RESULTS ............................................................ 20

TROUBLE DIAGNOSIS FOR SELF-DIAGNOSTIC 
ITEMS ........................................................................ 21

Inspection 1: Vehicle Speed Sensor ....................... 21
Inspection 2: Steering Angle Sensor  ...................... 21
Inspection 3: Stop Lamp Switch  ............................. 22
Inspection 4: Vertical G sensor ............................... 23

TROUBLE DIAGNOSIS FOR SYMPTOMS  .............. 25

Inspection 5: Hard or Soft Feel ............................... 25

SCS-2

TROUBLE DIAGNOSIS FOR ACTIVE DAMPER SUSPENSION

TROUBLE DIAGNOSIS FOR ACTIVE DAMPER SUSPENSION

PFP:25962

Precautions

EES000EX

PRELIMINARY CHECK

●

Check power steering fluid level.

●

Check power steering fluid line for improper attachment, leaks, cracks, damage, loose connections, chaf-
ing and deterioration.

●

Check tire pressure.

●

Check wheel alignment.

●

Check shock absorber for oil leakage or other damage.

Fail-Safe 

EES000EY

FAIL-SAFE FUNCTIONS

 The active damper suspension electronically controls the shock absorber dampening force. If, for some rea-
son, the dampening force falls under any of the conditions listed in the “Fail-safe items” table below, the fail-
safe system will activate to maintain a constant level of shock absorber dampening force. If symptoms (such
as unstable steering, unpleasant riding comfort, etc.) are pointed out, check and correct the malfunctioning
part or area using the diagnostic procedure outlined under “Diagnostic Procedure 6 (Hard or soft feel)”. Refer
to 

SCS-25, "TROUBLE DIAGNOSIS FOR SYMPTOMS"

FAIL-SAFE ITEMS

NOTE:
Even after the fail-safe function is canceled, the fail-safe processed history is retained in the control unit mem-
ory.

Item

Fail-safe input conditions

Fail-safe end conditions

Fail-safe processing

Vehicle speed sensor

●

Vehicle speed signal cannot be entered for 
more than 10 seconds when the vehicle is run-
ning with the engine revolution greater than 
1,500 rpm.

●

Vehicle speed signal changes from a value of 
greater than 30 km/h (19 MPH) to a value of 
less than 2 km/h (1 MPH) within 1.4 seconds.

A signal corresponding 
to a vehicle speed of 
greater than 2 km/h (1 
MPH) is entered.

●

Shock absorber dampen-
ing force is maintained at 
a preset value.

●

Power steering control 
current is maintained at 
approximately 0.18A.

Steering angle sensor

A steering signal of greater than 1

°

 does not 

change for more than 180 seconds when vehicle 
speed is greater than 60 km/h (37 MPH).

A steering signal of 
greater than 1

°

 is 

entered.

Shock absorber dampening 
force is maintained at a pre-
set value.

Steering angle (neu-
tral) signal

●

Steering neutral signal is not entered (“ON”) at 
all while vehicle is being driven a distance of 10 
km (6 miles) or more.

●

Steering neutral signal is not entered (“ON”) at 
all when steering wheel is turned at least 360

°

in 

either direction.

●

Steering neutral signal is staying “ON” only 
while steering wheel is being turned at least 50

°

 

in either direction.

More than one ON-OFF 
signal is entered.

Shock absorber dampening 
force is maintained at a pre-
set value.

Vertical G sensor

●

Vertical G sensor signal corresponding to a 
voltage of greater than 4.5 volts does not 
change for 2 seconds.

●

Vertical G sensor signal corresponding to a 
voltage of less than 0.5 volts does not change 
for 2 seconds.

Vertical G sensor signal 
corresponding to a volt-
age of greater than 1volt 
or less than 4 volts.

When any of the vertical G 
sensors are determined to 
be faulty, shock absorber 
dampening force is main-
tained at a preset value.

Stop lamp switch

Fail-safe system does not process data. 
DTC is displayed when self-diagnosis is performed.

TROUBLE DIAGNOSIS FOR ACTIVE DAMPER SUSPENSION

SCS-3

C

D

F

G

H

I

J

K

L

M

A

B

SCS

Active Damper Suspension Configuration 

EES000EZ

SYSTEM COMPONENTS

SEIA0272E

SCS-4

TROUBLE DIAGNOSIS FOR ACTIVE DAMPER SUSPENSION

SCHEMATIC

TEWM0020E