2007 INFINITI M35 power steering system

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
STC-5
[EPS]
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Revision: 2007 April2007 M35/M45
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

STC-12
[EPS]
TROUBLE DIAGNOSIS
Revision: 2007 April2007 M35/M45
7. CHECK VEHICLE SPEED SIGNAL CIRCUIT
Change the vehicle speed, and then check voltage waveform
between power steering control unit harness connector M8 and
ground.
OK or NG
OK >> Power steering control unit is inoperative. Replace it.
NG >> Check the following systems and replace if necessary.

Harness between unified meter & A/C amp and power steering control unit.

Unified meter & A/C amp and vehicle speed signal circuit Refer to DI-28, "UNIFIED METER
AND A/C AMP" .
8. CHECK ENGINE SPEED SIGNAL CIRCUIT
Warm up the engine, and then check voltage waveform between
power steering control unit harness connector M8 and ground when
the engine speed is the idling and at approximately 2,000 rpm.
OK or NG
OK >> Power steering control unit is inoperating. Replace it.
NG >> Check the following systems and replace if malfunction is detected.

Harness between ECM and power steering control unit

ECM engine speed signal circuit. Refer to EC-826, "CONSULT-II Function (ENGINE)" .
Terminal 3 – GroundRepeat Approx. 0 V and approx. 5 V
SGIA1237EELF1080D
Terminal 5 – GroundAt Idle
Approx. 2,000 rpmSGIA1289EPBIA3654J
PBIA3655J

TROUBLE DIAGNOSIS
STC-27
[RAS]
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Revision: 2007 April2007 M35/M45
STANDARD BY CONSULT-II
CAUTION:
The output signal indicates the RAS control unit calculation data. The normal values will be displayed
even in the event that the output circuit (harness) is open.
CONSULT-II Function (RAS/HICAS)NGS000EG
FUNCTION
CONSULT-II can display each self-diagnostic item using the diagnostic test modes shown following.
Monitor item Condition Reference values
VHCL SPEED SE [km/h] or [mph] Ignition switch ON or engine running Almost in accordance with the speedome-
ter display. It is not a malfunction, through
it might not be corresponding just after
ignition switch is turned ON.
STEERING ANG [°]Turning steering wheel clockwise or coun-
terclockwise.Displays the angle when the steering
wheel turns from the neutral position
ENGINE SPEED [rpm] Engine runningAlmost in accordance with tachometer dis-
play
POWER STR SOL [A]Accelerate the vehicle from 0 to 100 km/h
(0 to 62 MPH)0 km/h (0 MPH): Approx. 1.10 A
100 km/h (62 MPH): Approx. 0.54 A
RR ST ANG-MAI [V]
Perform the ACTIVE TEST and stroke the
actuator (with tires off the ground)Neutral: Approx. 2.4 V
Turn steering wheel to right for full stroke:
Approx. 4.4 V
Turn steering wheel to left for full stroke:
Approx. 0.4 V RR ST ANG-SUB [V]
RR ST ANG-VOL [V]
Ignition switch ON or engine runningApprox. 5 V
C/U VOLTAGE [V]Battery voltage (Approx. 12 V)
MOTOR VOLTAGE [V] Battery voltage (Approx. 12V)
MOTOR CURRENT [A]Perform the ACTIVE TEST and stroke the
actuator.It is normal when there is the current out-
put at stroke
MTR CRNT OPE [A]Turning steering wheel clockwise or coun-
terclockwise while ignition switch is ON or
running the engineNeutral (Steering force is zero and straight-
ahead position): Approx. 0 A
The value is changed according to steering
left or right
RR ANGLE OPE [°]RAS actuator assembly turned full right Approx. 1°
RAS actuator assembly neutral Approx. 0°
RAS actuator assembly turned full left Approx. - 1°
STOP LAMP SW [ON/OFF] Depressing or releasing brake pedalBrake pedal depressed: ON
Brake pedal not depressed: OFF
HICAS RELAY [ON/OFF]
Ignition switch ON or engine runningIgnition switch ON: ON
FAIL SAFE [ON/OFF] Not activated
WARNING LAMP (ON/OFF)RAS warning lamp ON: ON
RAS warning lamp OFF: OFF
Diagnostic test mode Function Reference page
SELF-DIAG RESULTSReceives self-diagnosis results from RAS control unit and
indicates DTCs.STC-28, "
SELF-DIAG
RESULT MODE"
DATA MONITORReceives input/output signals from RAS control unit and
indicates and stores them to facilitate locating cause of mal-
functions.STC-30, "DATA MONI-
TOR MODE"
CAN DIAG SUPPORT MNTRMonitors transmitting/receiving status of CAN communica-
tion.LAN-44, "CAN Diagnos-
tic Support Monitor"
ACTIVE TESTSends command to RAS actuator to change output signals
and check operation of output system.STC-30, "ACTIVE TEST
MODE"
ECU PART NUMBER Displays RAS control unit part number.STC-30, "RAS CONTROL
UNIT PART NUMBER"

STC-28
[RAS]
TROUBLE DIAGNOSIS
Revision: 2007 April2007 M35/M45
CONSULT-II SETTING PROCEDURE
Refer to GI-38, "CONSULT-II Start Procedure" .
SELF-DIAG RESULT MODE
Operation Procedure
1. Perform “CONSULT-II Start Procedure”. Refer to GI-38, "CONSULT-II Start Procedure" .
2. Touch “PRINT” to print out the self-diagnostic results if necessary. Check RAS warning lamp if “NO FAIL-
URE” is displayed.
3. Perform the appropriate inspection from the display item list, and repair or replace the malfunctioning
component. Refer to STC-28, "
Display Item List" .
Display Item List
CAUTION:
When malfunctions are detected in several systems, including the “CAN COMM [U1000]” and “CON-
TROL UNIT (CAN) [U1010]”, inspect the CAN communication system.
DTC Diagnostic item Diagnostic item is detected when... Check items
C1923 STEERING ANGLE SEN [NO CHANGE]While driving at 60 km/h (37 MPH)
or more, steering angle does not
change for a while.STC-39
C1924 STEERING ANGLE SEN [NO NEUT STATE]When driving some distance, no
neutral signal (ON signal) is input.STC-39
C1915 RR ST ANGLE SENSOR [MAIN SIGNAL]The main sensor input signal is
malfunctioning for some time
against the sensor power supply
value.STC-40
C1916 RR ST ANGLE SENSOR [SUB SIGNAL]When the main sensor input signal
is 2.4 - 2.6 V, the sub sensor input
signal is malfunctioning for some
time compared to the sensor power
supply value.STC-40
C1917 RR ST ANGLE SENSOR [OFFSET SIG1] An excessive difference has
occurred in the input values of main
sensor and sub sensor.STC-40
C1918 RR ST ANGLE SENSOR [OFFSET SIG2]
C1914 RR ST ANGLE SENSOR [ABNORMAL VOL]Higher or lower value compared to
the standard voltage.STC-40
C1921 MOTOR OUTPUTNo engine speed is input for a cer-
tain time.STC-44
C1911 MOTOR VOLTAGE [LOW VOLTAGE]The motor power supply voltage is
lower than ignition power supply
voltage with RAS motor relay ON.STC-35
C1912 MOTOR VOLTAGE [BAD OBSTRCT]The motor power supply voltage is
inputting for some time with motor
power supply OFF by RAS control
unit.STC-35
C1913 MOTOR OUTPUT [ABNORMAL SIG]When the motor current value is 10
A or more, actual output is exces-
sively low and the condition contin-
ues for some time.STC-37
C1902 MOTOR OUTPUT [REV CURRENT]The current flows in the opposite
direction when the motor current is
output. STC-37
C1903 MOTOR OUTPUT [NO CURRENT]The current flows when the motor
current is not output. STC-37
C1904 MOTOR OUTPUT [OVERCURRENT]The excessive high current flows
when the motor current is output.STC-37

TROUBLE DIAGNOSIS
STC-31
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Revision: 2007 April2007 M35/M45
Diagnosis Procedure with Self-Diagnosis Function (Without CONSULT-II)NGS000EL
DESCRIPTION
If a malfunction is detected in the system, the RAS warning lamp turns on and indicates the malfunction. At
that time, fail-safe activates, and then stops the function.
SELF-DIAGNOSIS PROCEDURE
1. Start engine.
2. Turn steering wheel left and right at 20° or more and 5 times or more within 10 seconds. And then depress
the service brake 5 times or more.
3. RAS warning lamp blinks (displays normal/malfunction).
SELF-DIAGNOSIS DISPLAY
RAS warning lamp blinks and displays the self-diagnostic results.

Only DTCs are displayed as the pattern shown in the figure, and
then repeat the display.

If all items are normal, RAS warning lamp blinks at 4 Hz cycle.
SELF-DIAGNOSIS DISPLAY ITEMS
HOW TO ERASE SELF-DIAGNOSIS
If there is the history data for when the fail-safe has activated in the past, erase the memory with CONSULT-II.
Refer to STC-29, "
How to Erase Self-Diagnostic Results" .
CAN CommunicationNGS000EM
CAN (Controller Area Network) is a serial communication line for real time application. It is an on-vehicle mul-
tiplex communication line with high data communication speed and excellent error detection ability. Many elec-
tronic control units are equipped onto a vehicle, and each control unit shares information and links with other
control units during operation (not independent). In CAN communication, control units are connected with 2
communication lines (CAN-H line, CAN-L line) allowing a high rate of information transmission with less wiring.
Each control unit transmits/receives data but selectively reads required data only. Refer to LAN-50, "
CAN Sys-
tem Specification Chart" .
SGIA1243E
DTC (warning lamp blinks) Diagnosis item Inspection item
11 RAS control unitSTC-35, "
Inspection 1: RAS Control Unit Malfunction"
12 Motor power supplySTC-35, "Inspection 2: Motor Power Supply System"
13 Motor outputSTC-37, "Inspection 3: RAS Motor Output Malfunction"
21 Vehicle speed signalSTC-38, "Inspection 4: Vehicle Speed Signal"
22 Steering angle signalSTC-39, "Inspection 5: Steering Angle Signal Malfunction"
24 Rear wheel steering angle (main)STC-40, "Inspection 6: Rear Main Signal and Rear Sub Signal
Malfunction"
25 Rear wheel steering angle (sub)STC-40, "Inspection 6: Rear Main Signal and Rear Sub Signal
Malfunction"
26 VDCSTC-43, "Inspection 7: VDC Malfunction"
33 Engine speed signalSTC-44, "Inspection 8: Engine Speed Signal Malfunction"

TF-1
TRANSFER
D DRIVELINE/AXLE
CONTENTS
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TF
Revision: 2007 April2007 M35/M45
TRANSFER
PRECAUTIONS .......................................................... 3
Precautions for Supplemental Restraint System
(SRS) “AIR BAG” and “SEAT BELT PRE-TEN-
SIONER” .................................................................. 3
Precautions .............................................................. 3
Service Notice or Precautions .................................. 4
PREPARATION ........................................................... 5
Special Service Tools ............................................... 5
Commercial Service Tools ........................................ 7
NOISE, VIBRATION AND HARSHNESS (NVH)
TROUBLESHOOTING ................................................ 8
NVH Troubleshooting Chart ..................................... 8
TRANSFER FLUID ..................................................... 9
Replacement ............................................................ 9
DRAINING ............................................................. 9
FILLING ................................................................. 9
Inspection ................................................................. 9
FLUID LEAKAGE AND FLUID LEVEL .................. 9
AWD SYSTEM .......................................................... 10
Power Transfer Diagram ........................................ 10
System Description ................................................ 10
DESCRIPTION .................................................... 10
ELECTRIC CONTROLLED COUPLING .............. 11
AWD CONTROL UNIT ......................................... 11
AWD WARNING LAMP ....................................... 12
System Diagram ..................................................... 12
COMPONENTS FUNCTION DESCRIPTION ..... 13
CAN Communication .............................................. 13
SYSTEM DESCRIPTION .................................... 13
TROUBLE DIAGNOSIS ............................................ 14
Fail-Safe Function .................................................. 14
How to Perform Trouble Diagnosis ........................ 14
BASIC CONCEPT ............................................... 14
Location of Electrical Parts ..................................... 15
Circuit Diagram ...................................................... 16
Wiring Diagram — AWD — .................................... 17
Trouble Diagnosis Chart for Symptoms ................. 20
AWD Control Unit Input/Output Signal Reference
Values .................................................................... 20AWD CONTROL UNIT INSPECTION TABLE ..... 20
CONSULT-II Function (ALL MODE AWD/4WD) ..... 21
FUNCTION .......................................................... 21
CONSULT-II SETTING PROCEDURE ................ 22
SELF-DIAG RESULT MODE ............................... 22
DATA MONITOR MODE ...................................... 24
ACTIVE TEST MODE ......................................... 25
AWD CONTROL UNIT PART NUMBER ............. 25
TROUBLE DIAGNOSIS FOR SYSTEM .................... 26
Power Supply Circuit for AWD Control Unit ............ 26
CONSULT-II REFERENCE VALUE IN DATA
MONITOR MODE ................................................ 26
DIAGNOSTIC PROCEDURE .............................. 26
AWD Control Unit ................................................... 27
DIAGNOSTIC PROCEDURE .............................. 27
ABS System ........................................................... 27
DIAGNOSTIC PROCEDURE .............................. 27
AWD Solenoid ........................................................ 28
CONSULT-II REFERENCE VALUE IN DATA
MONITOR MODE ................................................ 28
DIAGNOSTIC PROCEDURE .............................. 28
COMPONENT INSPECTION .............................. 30
AWD Actuator Relay ............................................... 31
CONSULT-II REFERENCE VALUE IN DATA
MONITOR MODE ................................................ 31
DIAGNOSTIC PROCEDURE .............................. 31
Engine Control Signal ............................................. 32
DIAGNOSTIC PROCEDURE .............................. 32
CAN Communication Line ...................................... 32
DIAGNOSTIC PROCEDURE .............................. 32
TROUBLE DIAGNOSIS FOR SYMPTOMS .............. 33
AWD Warning Lamp Does Not Turn ON When The
Ignition Switch Is Turned to ON .............................. 33
DIAGNOSTIC PROCEDURE .............................. 33
AWD Warning Lamp Does Not Turn OFF Several
Seconds after Engine Started ................................. 33
DIAGNOSTIC PROCEDURE .............................. 33
Heavy Tight-Corner Braking Symptom Occurs
When The Vehicle Is Driven and The Steering Wheel
Is Turned Fully to Either Side after The Engine Is

TF-20
TROUBLE DIAGNOSIS
Revision: 2007 April2007 M35/M45
Trouble Diagnosis Chart for SymptomsNDS000DK
If AWD warning lamp turns ON, perform self-diagnosis. Refer to TF-22, "SELF-DIAG RESULT MODE" .
NOTE:
Light tight-corner braking symptom may occur depending on driving conditions. This is not malfunction.
AWD Control Unit Input/Output Signal Reference ValuesNDS000DL
AWD CONTROL UNIT INSPECTION TABLE
Specifications with CONSULT-II
Symptom Condition Check item Reference page
AWD warning lamp does not turn ON when
the ignition switch is turned to ON.
(AWD warning lamp check)Ignition switch: ONCAN communication line
TF-33
Unified meter and A/C amp.
Unified meter control unit
AWD warning lamp does not turn OFF sev-
eral seconds after engine started.Engine runningCAN communication line
TF-33
Power supply and ground for AWD con-
trol unit
Unified meter and A/C amp.
Unified meter control unit
AWD solenoid
AWD actuator relay (integrated in AWD
control unit)
Wheel sensor
Heavy tight-corner braking symptom occurs
when the vehicle is driven and the steering
wheel is turned fully to either side after the
engine is started. (See NOTE.)

While driving

Steering wheel is
turned fully to either
sidesCAN communication line
TF-35Accelerator pedal position signal
AWD solenoid
Mechanical malfunction of electric con-
trolled coupling (clutch sticking etc.)
Vehicle does not enter AWD mode even
though AWD warning lamp turned to OFF.While drivingCAN communication line
TF-36
AWD solenoid
Mechanical malfunction of electric con-
trolled coupling (Mechanical engage-
ment of clutch is not possible.)
While driving, AWD warning lamp flashes
rapidly. (When flashing in approx. 1 minute
and then turning OFF.)
Rapid flashing: 2 times/secondWhile drivingProtection function is activated due to
heavy load to electric controlled cou-
pling. (AWD system is not malfunction-
ing. Also, optional distribution of torque
sometimes becomes rigid before lamp
flashes rapidly, but it is not malfunction.)TF-37
While driving, AWD warning lamp flashes
slowly. (When continuing to flash until turn-
ing ignition switch OFF)
Slow flashing: 1 time/2 seconds
While driving

Vehicle speed: 20 km/h
(12 MPH) or moreTire size is different between front and
rear of vehicle.TF-37
Monitor item [Unit] Content Condition Display value
FR RH SENSOR [km/h] or [mph]Wheel speed (Front wheel
right)Vehicle stopped 0.00 km/h (0.00 mph)
Vehicle running
CAUTION:
Check air pressure of tire under
standard condition.Approximately equal to
the indication on speed-
ometer (Inside of ±10%)
FR LH SENSOR [km/h] or [mph]Wheel speed (Front wheel
left)Vehicle stopped 0.00 km/h (0.00 mph)
Vehicle running
CAUTION:
Check air pressure of tire under
standard condition.Approximately equal to
the indication on speed-
ometer (Inside of ±10%)