2006 INFINITI M35 ground

STC-1
STEERING CONTROL SYSTEM
G STEERING
CONTENTS
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SECTION STC
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STC
Revision: 2006 January2006 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) .................................. 28
FUNCTION .......................................................
... 28
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
SYSTEM DESCRIPTION .................................... 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

STC-8
[EPS]
TROUBLE DIAGNOSIS
Revision: 2006 January2006 M35/M45
Control Unit Input/Output Signal StandardNGS000E0
STANDARD BY CIRCUIT TESTER AND OSCILLOSCOPE
CAUTION:
When checked using a circuit tester for voltage measurement, connector terminals should not be
forcefully extended.
Te r m i n a l
Measuring
pointMeasuring condition Standard
+ (wire color) –
1 (GR)
GroundIGN Ignition switch ON. Battery voltage (Approx. 12 V)
2 (B) Ground — —
3 (L)Vehicle speed
signal
(2-pulse)At 40 km/h (25MPH)
5 (Y)Engine
speed signalAt idle after warming up
At approx. 2,000 rpm
7 (G)Power steer-
ing solenoid
valveNormal
(Vehicle speed)0 km/h (0 MPH) Approx. 4.4 - 6.6 V
100 km/h (62 MPH) Approx. 2.4 - 3.6 V
In fail-safe mode
(Engine speed)0 - 1,500 rpm Approx. 4.4 - 6.6 V
1,500 - 3,000 rpm Approx. 3.5 V
More than 3,000 rpm Approx. 2.1 V
ELF1080D
PBIA3654J
PBIA3655J

TROUBLE DIAGNOSIS
STC-9
[EPS]
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STC
Revision: 2006 January2006 M35/M45
For Fast and Accurate Trouble DiagnosisNGS000E1
Check the following items with the vehicle stopped
Is air pressure and size of tires proper?
Is the specified part used for the steering wheel?
Is control unit a genuine part?
Are there any fluid leakage from steering gear assembly, power steering oil pump, and hydraulic pipes,
etc? Refer to PS-8, "
POWER STEERING FLUID" .
Is the fluid level proper? Refer to PS-8, "POWER STEERING FLUID" .
Is the wheel alignment adjusted properly? Refer to FSU-19, "SERVICE DATA AND SPECIFICATIONS
(SDS)" (2WD), FSU-36, "SERVICE DATA AND SPECIFICATIONS (SDS)" (AWD).
Are there any damage or modification to suspension or body resulting in increased weight or altered
ground clearance?
Check each link installation condition of suspension and axle.
Check each connector connection condition.
Check the following items while driving the vehicle
Check conditions when the malfunction occurred (5W 1H).
Is the engine condition normal?
Basic InspectionNGS000E2
POWER SUPPLY CIRCUIT TERMINAL LOOSENESS AND BATTERY
Check battery terminals for looseness on both positive and negative ones and ground connection. Also make
sure that battery voltage does not drop.
Inspection: Power Steering Control Unit Power Supply Circuit and GroundNGS000E3
1. CHECK POWER STEERING CONTROL UNIT CONNECTOR
Turn ignition switch OFF, disconnect power steering control unit harness connector, and check terminal for
deformation, disconnection, looseness, etc.
OK or NG
OK >> GO TO 2.
NG >> Connector terminal connection is loose, damaged, open, or shorted. Repair or replace the termi-
nal.
2. CHECK POWER STEERING CONTROL UNIT GROUND CIRCUIT
Disconnect power steering control unit harness connector M8, and
then check continuity between power steering control unit harness
connector M8 and ground.
OK or NG
OK >> GO TO 3.
NG >> Ground circuit open or shorted. Repair or replace any
inoperative parts. Terminal 2 – Ground : Continuity exist.
SGIA1231E

STC-10
[EPS]
TROUBLE DIAGNOSIS
Revision: 2006 January2006 M35/M45
3. CHECK POWER STEERING CONTROL UNIT POWER SUPPLY CIRCUIT
Turn ignition switch ON, and then check voltage between power
steering control unit harness connector M8 and ground.
OK or NG
OK >> Power supply and ground circuit are normal.
NG >> Power supply circuit open or shorted. Repair or replace
any inoperative parts.
Symptom: The Steering Force Does Not Change Smoothly According to the
Vehicle Speed
NGS000E4
Heavy steering force with the static steering/light steering force during high-speed driving
1. POWER STEERING SOLENOID VALVE SIGNAL INSPECTION 1
1. Start engine.
2. Change the vehicle speed from 0 to 100 km/h (0 to 62 MPH)
slowly, and then check voltage between power steering control
unit harness connector M8 and ground.
OK or NG
OK >> GO TO 2.
NG >> GO TO 7.
2. POWER STEERING SOLENOID VALVE SIGNAL INSPECTION 2
1. Activate fail-safe function by running the engine speed at 1,500 rpm or higher for 10 seconds with the
vehicle stopped.
2. Change the engine speed to the idling, to approximately 1,600
rpm, and to approximately 3,000 rpm slowly, and then check
voltage between power steering control unit harness connector
M8 and ground.
OK or NG
OK >> GO TO 3.
NG >> GO TO 8.
3. CHECK POWER STEERING SOLENOID VALVE CONNECTOR
Turn ignition switch OFF, disconnect power steering solenoid valve harness connector, and check terminal for
deformation, disconnection, looseness, etc.
OK or NG
OK >> GO TO 4.
NG >> Harness or connector open or shorted. Repair or replace any inoperative parts. Terminal 1 – ground : Battery voltage (Approx. 12 V)
SGIA1232E
Terminal 7 – ground : The voltage has changed from
approximately 4.4 - 6.6 V to
approximately 2.4 - 3.6 V
SGIA1233E
Terminal 7 – ground : The voltage has changed from
approximately 5.5 V to approxi-
mately 2.1 V step-by-step.
SGIA1233E

TROUBLE DIAGNOSIS
STC-11
[EPS]
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STC
Revision: 2006 January2006 M35/M45
4. CHECK POWER STEERING SOLENOID VALVE POWER SUPPLY CIRCUIT
Check continuity between power steering control unit harness con-
nector M8 and power steering solenoid valve harness connector F25
(VQ35DE), E211 (VK45DE).
OK or NG
OK >> GO TO 5.
NG >> Open or short in harness. Repair or replace any inoper-
ative parts.
5. CHECK POWER STEERING SOLENOID VALVE GROUND CIRCUIT
Check continuity between power steering solenoid valve harness
connector F25 (VQ35DE), E211 (VK45DE) and ground.
OK or NG
OK >> GO TO 6.
NG >> Open or short in harness. Repair or replace any inoper-
ative parts.
6. CHECK POWER STEERING SOLENOID VALVE
Apply voltage power steering solenoid valve connector, and then
make sure that the operating sound (clicking sound) is heard.
OK or NG
OK >> Perform steering turning torque inspection. Refer to PS-
10, "CHECKING STEERING WHEEL TURNING
FORCE" .
NG >> Power steering solenoid valve is inoperative. Replace.
Power steering control unit Power steering solenoid valve Continuity
Terminal 7 Terminal 1 Yes
SGIA1235E
Terminal 2 – Ground : Continuity exist.
SGIA1236E
Terminal 1 (+) - 2 (–) : Operating sound is heard.
SGIA1284E

STC-12
[EPS]
TROUBLE DIAGNOSIS
Revision: 2006 January2006 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.
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-846, "CONSULT-II Function (ENGINE)" .
Terminal 3 – GroundRepeat Approx. 0 V and approx. 5 V
SGIA1237EELF1080D
Terminal 5 – GroundAt Idle
Approx. 2,000 rpmSGIA1289EPBIA3654J
PBIA3655J

STC-14
[RAS]
REAR ACTIVE STEER
Revision: 2006 January2006 M35/M45
Disassembly and AssemblyNGS000E6
COMPONENTS
DISASSEMBLY
1. Remove mounting bolts of RAS motor assembly, and then remove RAS motor assembly, ground terminal,
O-ring from RAS actuator.
2. Remove mounting bolt of rear wheel steering angle sensor, and then remove rear wheel steering angle
sensor, O-ring from RAS actuator.
INSPECTION AFTER DISASSEMBLY
Check RAS actuator bracket (rear wheel steering angle sensor mounting area) for crush, deformation, cracks,
or other damage. Replace the RAS actuator malfunction is detected.
ASSEMBLY
Assembly is the reverse order of disassembly. For tightening torque, refer to STC-14, "COMPONENTS" .
After assembling RAS actuator assembly (after removing and installing rear wheel angle sensor and RAS
motor), perform the neutral position adjustment.
Neutral Position AdjustmentNGS000E7
Adjust neutral position after performing the following procedure.
Removing and installing or replacing the RAS actuator assembly
Disassembling the RAS actuator assembly (when removing rear wheel steering angle sensor and RAS
motor)
CAUTION:
Perform the neutral position adjustment after installing the RAS actuator assembly to the vehicle.
Before that, remove the rear lower link from the RAS actuator.
1. Disconnect harness connector and remove rear wheel steering angle sensor from the RAS actuator
assembly.
2. Disconnect RAS motor harness connector.
3. Turn ignition switch ON.
1. Ground terminal 2. RAS motor assembly 3. O-ring
4. RAS actuator 5. Rear wheel steering angle sensor
Refer to GI-11, "
Components" , for the symbols in the figure.
SGIA1052J

STC-26
[RAS]
TROUBLE DIAGNOSIS
Revision: 2006 January2006 M35/M45
Control Unit Input/Output Signal StandardNGS000EF
CIRCUIT TESTER REFERENCE VALUE
CAUTION:
When checked using a circuit tester for voltage measurement, connector terminals should not be
forcefully extended.
Terminal
Measuring point Measuring condition Standard
+
(wire color)–
1 (L) — CAN-H —
4 (G)
GroundRR MAIN SIG Neutral Approx. 2.4 V
5 (W) RR VCCIgnition switch ON Approx. 5 V
Ignition switch OFF Approx. 0 V
7 (R) RR SUB SIG Neutral Approx. 2.4 V
8 (P) — CAN-L —
15 (B/W)
GroundRR SEN GND — Continuity exit
22 (P/L) STOP/L SWBrake pedal depressed Battery voltage (Approx. 12 V)
Brake pedal not depressed Approx. 0 V
25 (L/W) RLYIgnition switch ON Battery voltage (Approx. 12 V)
Ignition switch OFF Approx. 0 V
26 (G/W) WARNON Approx. 1.4 V or less
OFF Ignition voltage: 2.8 V or more
27 (G/B) IGNIgnition switch ON Battery voltage (Approx. 12 V)
Ignition switch OFF Approx. 0 V
34 (B) GND — Continuity exit
36 (LG) P/S SOLNormal (Vehicle speed)0 km/h (0 MPH) Approx. 4.4 - 6.6 V
100 km/h (62 MPH) Approx. 2.4 - 3.6 V
In fail-safe mode
(Engine speed)0 - 1,500 rpm Approx. 4.4 - 6.6 V
1,500 - 3,000 rpm Approx. 3.5 V
3,000 rpm or more Approx. 2.1 V
37 (L/Y) MOTOR VCCIgnition switch ON Battery voltage (Approx. 12 V)
Ignition switch OFF Approx. 0 V
38 (W) MTR-1 (RH) —
39 (B) MTR-2 (LH) —
40 (B/W) MOTOR GND — Continuity exit