2007 INFINITI M35 steering system

PRECAUTIONS
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PRECAUTIONSPFP:00001
Precautions for Supplemental Restraint System (SRS) “AIR BAG” and “SEAT
BELT PRE-TENSIONER”
NHS0008O
The Supplemental Restraint System such as “AIR BAG” and “SEAT BELT PRE-TENSIONER”, used along
with a front seat belt, helps to reduce the risk or severity of injury to the driver and front passenger for certain
types of collision. This system includes seat belt switch inputs and dual stage front air bag modules. The SRS
system uses the seat belt switches to determine the front air bag deployment, and may only deploy one front
air bag, depending on the severity of a collision and whether the front occupants are belted or unbelted.
Information necessary to service the system safely is included in the SRS and SB section of this Service Man-
ual.
WARNING:

To avoid rendering the SRS inoperative, which could increase the risk of personal injury or death
in the event of a collision which would result in air bag inflation, all maintenance must be per-
formed by an authorized NISSAN/INFINITI dealer.

Improper maintenance, including incorrect removal and installation of the SRS, can lead to per-
sonal injury caused by unintentional activation of the system. For removal of Spiral Cable and Air
Bag Module, see the SRS section.

Do not use electrical test equipment on any circuit related to the SRS unless instructed to in this
Service Manual. SRS wiring harnesses can be identified by yellow and/or orange harnesses or
harness connectors.
Precautions for SRS “AIR BAG” and “SEAT BELT PRE-TENSIONER” ServiceNHS0008P

Do not use electrical test equipment to check SRS circuits unless instructed to in this Service Manual.

Before servicing the SRS, turn ignition switch OFF, disconnect both battery cables and wait at least 3 min-
utes.
For approximately 3 minutes after the cables are removed, it is still possible for the air bag and seat belt
pre-tensioner to deploy. Therefore, do not work on any SRS connectors or wires until at least 3 minutes
have passed.

Diagnosis sensor unit must always be installed with their arrow marks “⇐” pointing towards the front of the
vehicle for proper operation. Also check diagnosis sensor unit for cracks, deformities or rust before instal-
lation and replace as required.

The spiral cable must be aligned with the neutral position since its rotations are limited. Do not turn steer-
ing wheel and column after removal of steering gear.

Handle air bag module carefully. Always place driver and front passenger air bag modules with the pad
side facing upward and seat mounted front side air bag module standing with the stud bolt side facing
down.

Conduct self-diagnosis to check entire SRS for proper function after replacing any components.

After air bag inflates, the front instrument panel assembly should be replaced if damaged.

Always replace instrument panel pad following front passenger air bag deployment.
Occupant Classification System PrecautionNHS0008Q
Replace occupant classification system control unit and passenger front seat cushion as an assembly.
Refer to SE-166, "
Passenger's Seat Components" .

DRIVER AIR BAG MODULE
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Revision: 2007 April2007 M35/M45
INSTALLATION
Install in the reverse order of removal.
CAUTION:

Fix the air bag module harness (shown as A in the figure) to
the harness fixing hook (shown as B in the figure).

Be careful not to damage the harness while installing.

Tighten the special bolts after exactly adjusting the centers of fixing holes on the air bag module
side and the steering wheel side. If the holes are misaligned, the bolt threads are damaged and the
module is not installed securely.

After the work is completed, make sure no system malfunction is detected by air bag warning
lamp.

In case that malfunction is detected by the air bag warning lamp, reset by the self-diagnosis func-
tion and delete the memory by CONSOULT–II.

In case that malunction is still detected after the above operation, peform self-diagnosis to repair
malfunctions. Refer to SRS-20, "
SRS Operation Check" .
PHIA0885J

SPIRAL CABLE
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Revision: 2007 April2007 M35/M45
CAUTION:

The spiral cable may snap by steering operation if the cable
is installed in an improper position.

The neutral position is set as follows.
Turn quietly the spiral cable clockwise to the end position.
Then turn it counterclockwise (about 2 and harf turns) and
stop turning at the point on which the stopper insertion
holes are in the same position.
The service part is installed in the neutral position by the
stopper and can be set without adjusting after the stopper
is removed.

Do not turn the spiral cable rashly and also beyond the limit
number of turns. (These will cause cable snap.)

Adjust the spiral cable locating pin (showed as A inthe fig-
ure) to the steering wheel locating pin hole (showed as C in
the figuer).

Secure the air bag harness with the harness fixing hook.

After the work is completed, make sure no system malfunc-
tion is detected by air bag warning lamp.

In case that malfunction is detected by the air bag warning
lamp, reset by the self-diagnosis function and delete the
memory by CONSULT−II.

In case that malfunction is still detected after the above
operation, perform self-diagnosis to repair malfunctions.
Refer to SRS-20, "
SRS Operation Check" .
PHIA0887J

STC-1
STEERING CONTROL SYSTEM
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CONTENTS
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SECTION STC
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STC
Revision: 2007 April2007 M35/M45
STEERING CONTROL SYSTEM
EPS
SYSTEM DESCRIPTION ............................................ 3
Components ............................................................. 3
Components (Models with Rear Active Steer) ......... 3
Electronically Controlled Power Steering System
Function ................................................................... 3
Fail-Safe Function .................................................... 4
FAIL-SAFE INPUT/CANCEL CONDITIONS ......... 4
TROUBLE DIAGNOSIS .............................................. 5
How to Perform Trouble Diagnosis .......................... 5
BASIC CONCEPT ................................................. 5
Component Parts Location ....................................... 5
Wiring Diagram — EPS — ....................................... 6
Control Unit Input/Output Signal Standard ............... 8
STANDARD BY CIRCUIT TESTER AND OSCIL-
LOSCOPE ............................................................. 8
For Fast and Accurate Trouble Diagnosis ................ 9
Basic Inspection ....................................................... 9
POWER SUPPLY CIRCUIT TERMINAL LOOSE-
NESS AND BATTERY .......................................... 9
Inspection: Power Steering Control Unit Power Sup-
ply Circuit and Ground ............................................. 9
Symptom: The Steering Force Does Not Change
Smoothly According to the Vehicle Speed ............. 10
RAS
REAR ACTIVE STEER ............................................. 13
Removal and Installation ........................................ 13
COMPONENTS .................................................. 13
REMOVAL ........................................................... 13
INSTALLATION ................................................... 13
Disassembly and Assembly ................................... 14
COMPONENTS .................................................. 14
DISASSEMBLY ................................................... 14
INSPECTION AFTER DISASSEMBLY ............... 14
ASSEMBLY ......................................................... 14
Neutral Position Adjustment ................................... 14
SYSTEM DESCRIPTION .......................................... 16
Components ........................................................... 16RAS (Rear Active Steer) Function .......................... 16
Fail-Safe Function .................................................. 17
TROUBLE DIAGNOSIS ............................................ 18
How to Perform Trouble Diagnosis ......................... 18
BASIC CONCEPT ............................................... 18
Component Parts Location ..................................... 19
Schematic ............................................................... 20
Wiring Diagram — RAS — ..................................... 21
Control Unit Input/Output Signal Standard ............. 26
CIRCUIT TESTER REFERENCE VALUE ........... 26
STANDARD BY CONSULT-II .............................. 27
CONSULT-II Function (RAS/HICAS) ...................... 27
FUNCTION .......................................................... 27
CONSULT-II SETTING PROCEDURE ................ 28
SELF-DIAG RESULT MODE ............................... 28
DATA MONITOR MODE ...................................... 30
ACTIVE TEST MODE ......................................... 30
RAS CONTROL UNIT PART NUMBER .............. 30
Diagnosis Procedure with Self-Diagnosis Function
(Without CONSULT-II) ............................................ 31
DESCRIPTION .................................................... 31
SELF-DIAGNOSIS PROCEDURE ...................... 31
SELF-DIAGNOSIS DISPLAY .............................. 31
SELF-DIAGNOSIS DISPLAY ITEMS .................. 31
HOW TO ERASE SELF-DIAGNOSIS ................. 31
CAN Communication .............................................. 31
For Fast and Accurate Trouble Diagnosis .............. 32
Basic Inspection ..................................................... 32
BASIC INSPECTION 1: POWER SUPPLY CIR-
CUIT TERMINAL LOOSENESS AND BATTERY ... 32
BASIC INSPECTION 2: RAS WARNING LAMP
INSPECTION ...................................................... 32
BASIC INSPECTION 3: RAS CONTROL UNIT
POWER SUPPLY CIRCUIT AND GROUND CIR-
CUIT INSPECTION ............................................. 32
Trouble Diagnosis Chart ......................................... 33
SELF-DIAGNOSIS .............................................. 33
DIAGNOSIS CHART BY SYMPTOM .................. 34
Inspection 1: RAS Control Unit Malfunction ........... 35
Inspection 2: Motor Power Supply System ............. 35

STC-2Revision: 2007 April2007 M35/M45 Inspection 3: RAS Motor Output Malfunction ......... 37
Inspection 4: Vehicle Speed Signal ........................ 38
Inspection 5: Steering Angle Signal Malfunction .... 39
Inspection 6: Rear Main Signal and Rear Sub Signal
Malfunction ............................................................. 40
Inspection 7: VDC Malfunction ............................... 43
Inspection 8: Engine Speed Signal Malfunction ..... 44
Inspection 9: CAN Communication System Mal-
function ................................................................... 44Inspection 10: Stop Lamp Switch Harness ............. 45
Inspection 11: RAS Warning Lamp Harness ........... 46
Diagnosis Chart by Symptom 1 .............................. 47
Diagnosis Chart by Symptom 2 .............................. 47
Check RAS Static/Dynamic Characteristics ............ 49
Component Inspection ............................................ 50
RAS MOTOR RELAY ........................................... 50
RAS MOTOR ....................................................... 50
REAR WHEEL STEERING ANGLE SENSOR .... 50

SYSTEM DESCRIPTION
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[EPS]SYSTEM DESCRIPTIONPFP:00000
ComponentsNGS000DT
Components (Models with Rear Active Steer)NGS000DU
Electronically Controlled Power Steering System FunctionNGS000DV

Vehicle speed sensing electronically controlled power steering
(that properly controls the steering force by the vehicle speed)
has been adopted. When it is normal, it controls the power
steering solenoid valve according to the vehicle speed as shown
in the figure and makes the steering force proper.

For the models with RAS (Rear Active Steer), RAS control unit
performs the same control as power steering control unit. For
schematic, refer to STC-20, "
Schematic" and trouble diagnosis,
refer to STC-47, "
Diagnosis Chart by Symptom 2" .
SGIA1056E
SGIA1094E
SST696CA

STC-4
[EPS]
SYSTEM DESCRIPTION
Revision: 2007 April2007 M35/M45
Fail-Safe FunctionNGS000DW
When the fail-safe function operate, it controls power steering sole-
noid valve by the engine speed as shown in the figure and maintains
the steering force.
FAIL-SAFE INPUT/CANCEL CONDITIONS
CAUTION:
Fail-safe function is activated when the engine runs at 1,500 rpm or higher for 10 seconds with the vehicle stopped. This is
normal and the fail-safe function is automatically deactivated when a vehicle speed signal of 2 km/h (1.2 MPH) or higher is
input or the ignition switch is turned OFF.
SGIA0411E
Input conditions Cancel conditions
When vehicle runs at an engine speed of 1,500 rpm or higher and no vehicle speed signal
is received for 10 seconds.

A vehicle speed of 2 km/h (1.2 MPH) or
more is input.

Turn the ignition switch ON after turn-
ing it OFF. The continuous vehicle speed signal 30 km/h (19 MPH) or more suddenly drops to less
than 2 km/h (1.2 MPH) within 1.4 seconds.

TROUBLE DIAGNOSIS
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TROUBLE DIAGNOSISPFP:00004
How to Perform Trouble DiagnosisNGS000DX
BASIC CONCEPT

The most important point to perform trouble diagnosis is to understand systems (control and mechanism)
in vehicle thoroughly.

It is also important to clarify customer complaints before inspec-
tion.
First of all, reproduce symptom, and understand it fully.
Ask customer about his/her complaints carefully. In some cases,
they will be necessary to check symptom by driving vehicle with
customer.
CAUTION:
Customers are not professionals. Do not assume “maybe
customer means...” or “maybe customer mentioned this
symptom”.

It is essential to check symptoms right from beginning in order to
repair a malfunction completely.
For an intermittent malfunction, it is important to reproduce
symptom based on interview with customer and past examples.
Do not perform inspection on ad hoc basis. Most intermittent
malfunctions are caused by poor contacts. In this case, it will be
effective to shake suspected harness or connector by hand.
When repairs are performed without any symptom check, no
one can judge if malfunction has actually been eliminated.

Always read “GI General Information” to confirm general precau-
tions. Refer to GI-4, "
General Precautions" .
Component Parts LocationNGS000DY
SEF234G
SEF233G
1. Power steering control unit
(Back of center console assembly)2. Power steering solenoid valve
SGIA1105J