control unit INFINITI M35 2007 Factory Service Manual

BRC-1
BRAKE CONTROL SYSTEM
F BRAKES
CONTENTS
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SECTION BRC
A
B
BRC
Revision: 2007 April2007 M35/M45
BRAKE CONTROL SYSTEM
VDC/TCS/ABS
PRECAUTIONS .......................................................... 3
Precautions for Supplemental Restraint System
(SRS) “AIR BAG” and “SEAT BELT PRE-TEN-
SIONER” .................................................................. 3
Precautions for Procedures without Cowl Top Cover ..... 3
Precautions for Brake System .................................. 3
Precautions for Brake Control .................................. 4
PREPARATION ........................................................... 5
Special Service Tools ............................................... 5
Commercial Service Tools ........................................ 5
ON-VEHICLE SERVICE ............................................. 6
Adjustment of Steering Angle Sensor Neutral Posi-
tion ........................................................................... 6
SYSTEM DESCRIPTION ............................................ 7
System Diagram ....................................................... 7
Functions .................................................................. 7
ABS ....................................................................... 7
EBD ....................................................................... 7
TCS ....................................................................... 8
VDC ....................................................................... 8
ECD ....................................................................... 8
Operation That Is Not "System Error" ...................... 8
ABS ....................................................................... 8
TCS ....................................................................... 8
VDC ....................................................................... 8
Hydraulic Circuit Diagram ........................................ 9
CAN Communication ................................................ 9
SYSTEM DESCRIPTION ...................................... 9
TROUBLE DIAGNOSIS ............................................ 10
Fail-Safe Function .................................................. 10
ABS, EBD SYSTEM ............................................ 10
VDC/TCS ............................................................ 10
How to Perform Trouble Diagnoses ....................... 10
BASIC CONCEPT ............................................... 10
DIAGNOSIS FLOW CHART ................................ 11
ASKING COMPLAINTS ...................................... 12
EXAMPLE OF DIAGNOSIS WORKSHEET ........ 12
Component Parts Location ..................................... 13
Schematic .............................................................. 14Wiring Diagram — VDC — ..................................... 15
Control Unit Input/Output Signal Standard ............. 21
REFERENCE VALUE FROM CONSULT-II ......... 21
CONSULT-II Functions (ABS) ................................ 23
CONSULT-II MAIN FUNCTION ........................... 23
CONSULT-II SETTING PROCEDURE ................ 23
Self-Diagnosis ........................................................ 24
OPERATION PROCEDURE ................................ 24
ERASE MEMORY ............................................... 24
DISPLAY ITEM LIST ........................................... 25
Data Monitor ........................................................... 28
OPERATION PROCEDURE ................................ 28
DISPLAY ITEM LIST ........................................... 28
Active Test .............................................................. 30
OPERATION PROCEDURE ................................ 30
TEST ITEMS ....................................................... 31
For Fast and Accurate Diagnosis ........................... 32
PRECAUTIONS FOR DIAGNOSIS ..................... 32
Basic Inspection ..................................................... 33
BASIC INSPECTION 1: BRAKE FLUID LEVEL,
LEAK INSPECTION AND BRAKE PAD .............. 33
BASIC INSPECTION 2: LOOSENESS OF
POWER SYSTEM TERMINALS AND BATTERY ... 33
BASIC INSPECTION 3: ABS WARNING LAMP,
BRAKE WARNING LAMP, VDC OFF INDICATOR
LAMP AND SLIP INDICATOR LAMP .................. 33
TROUBLE DIAGNOSIS FOR SYSTEM .................... 34
Wheel Sensor Circuit .............................................. 34
INSPECTION PROCEDURE .............................. 34
Engine System ....................................................... 36
INSPECTION PROCEDURE .............................. 36
ABS Actuator and Electric Unit (Control Unit) ........ 36
INSPECTION PROCEDURE .............................. 36
ABS Actuator and Electric Unit (Control Unit) Power
Supply and Ground Circuit ..................................... 37
INSPECTION PROCEDURE .............................. 37
ABS Motor and Motor Relay Circuit ........................ 38
INSPECTION PROCEDURE .............................. 38
Solenoid, VDC Change-Over Valve and Actuator
Relay Circuit ........................................................... 39

BRC-2Revision: 2007 April2007 M35/M45 INSPECTION PROCEDURE ............................... 39
Pressure Sensor Circuit .......................................... 40
INSPECTION PROCEDURE ............................... 40
Steering Angle Sensor Circuit ................................. 41
INSPECTION PROCEDURE ............................... 41
Stop Lamp Switch Circuit ........................................ 43
INSPECTION PROCEDURE ............................... 43
Yaw Rate/Side G Sensor Circuit ............................. 44
INSPECTION PROCEDURE ............................... 44
Brake Fluid Level Switch Circuit ............................. 46
INSPECTION PROCEDURE ............................... 46
RAS Control Unit Circuit (With RAS) ...................... 47
INSPECTION PROCEDURE ............................... 47
ICC Sensor Integrated Unit Circuit (With ICC) ........ 48
INSPECTION PROCEDURE ............................... 48
CAN Communication Circuit ................................... 48
INSPECTION PROCEDURE ............................... 48
VDC OFF Switch Circuit ......................................... 49
INSPECTION PROCEDURE ............................... 49
Parking Brake Switch Circuit .................................. 50
INSPECTION PROCEDURE ............................... 50
Warning Lamp and Indicator Lamp Circuit ............. 50
INSPECTION PROCEDURE ............................... 50
TROUBLE DIAGNOSIS FOR SYMPTOMS .............. 51
Excessive ABS Function Operation Frequency ...... 51
Unexpected Pedal Reaction ................................... 51The Braking Distance Is Long ................................. 52
ABS Function Does Not Operate ............................ 52
Pedal Vibration or ABS Operation Sound Occurs ... 52
Vehicle Jerks During VDC/TCS/ABS Control .......... 53
WHEEL SENSOR ...................................................... 54
Removal and Installation ......................................... 54
COMPONENT ...................................................... 54
REMOVAL ............................................................ 54
INSTALLATION .................................................... 54
SENSOR ROTOR ...................................................... 56
Removal and Installation ......................................... 56
REMOVAL ............................................................ 56
INSTALLATION .................................................... 56
ACTUATOR AND ELECTRIC UNIT (ASSEMBLY) ... 57
Removal and Installation ......................................... 57
COMPONENT ...................................................... 57
REMOVAL ............................................................ 57
INSTALLATION .................................................... 58
G-SENSOR ................................................................ 59
Removal and Installation ......................................... 59
REMOVAL ............................................................ 59
INSTALLATION .................................................... 59
STEERING ANGLE SENSOR ................................... 60
Removal and Installation ......................................... 60
REMOVAL ............................................................ 60
INSTALLATION .................................................... 60

PRECAUTIONS
BRC-3
[VDC/TCS/ABS]
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BRC
Revision: 2007 April2007 M35/M45
[VDC/TCS/ABS]PRECAUTIONSPFP:00001
Precautions for Supplemental Restraint System (SRS) “AIR BAG” and “SEAT
BELT PRE-TENSIONER”
NFS000PY
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 Procedures without Cowl Top CoverNFS000PZ
When performing the procedure after removing cowl top cover, cover
the lower end of windshield with urethane, etc.
Precautions for Brake SystemNFS000Q0

Recommended fluid is brake fluid “DOT 3”. Refer to MA-12, "RECOMMENDED FLUIDS AND LUBRI-
CANTS" .

Do not reuse drained brake fluid.

Be careful not to splash brake fluid on painted surface of body. If brake fluid is splashed on painted sur-
faces of body immediately wipe off then with cloth and then wash it away with water.

Do not use mineral oils such as gasoline or kerosene. They will ruin rubber parts of the hydraulic system.

Use a flare nut wrench when removing flare nuts, and use a flare
nut crowfoot and torque wrench when tighten brake tube flare
nuts.

When installing brake tubes, be sure to check torque.

Brake system is an important safety part. If a brake fluid leak is
detected, always disassemble the affected part. If a malfunction
is detected, replace part with a new one.

Before working, turn ignition switch OFF and disconnect con-
nectors of ABS actuator and electric unit (control unit) or battery
negative terminal.
WARNING:
Clean brake pads and shoes with a waste cloth, then wipe with a dust collector.
PIIB3706J
SBR686C

BRC-4
[VDC/TCS/ABS]
PRECAUTIONS
Revision: 2007 April2007 M35/M45
Precautions for Brake ControlNFS000Q1

Just after starting vehicle after ignition switch ON, brake pedal may vibrate or motor operating noise may
be heard from engine compartment. This is normal condition.

When an error is indicated by ABS or another warning lamp, collect all necessary information from cus-
tomer (what symptoms are present under what conditions) and check for simple causes before starting
diagnostic servicing. Besides electrical system inspection, check brake booster operation, brake fluid
level, and oil leaks.

If tire size and type are used in an improper combination, or brake pads are not Genuine NISSAN parts,
stopping distance or steering stability may deteriorate.

ABS might be out of order or malfunctions by putting a radio (wiring inclusive), an antenna and a lead-in
wire near the control unit.

If aftermarket parts (car stereo, CD player, etc.) have been installed, check for incidents such as harness
pinches, open circuits, and improper wiring.

VDC system may not operate normally or a VDC OFF indicator lamp or SLIP indicator lamp may light.
–When replacing the following parts with parts other than genuine parts or making modifications: Suspen-
sion-related parts (shock absorber, spring, bushing, etc.), tires, wheels (other than specified sizes), brake-
related parts (pad, rotor, caliper, etc.), engine-related parts (muffler, ECM, etc.) and body reinforcement-
related parts (roll bar, tower bar, etc.).
–When driving with worn or deteriorated suspension, tires and brake-related parts.

BRC-6
[VDC/TCS/ABS]
ON-VEHICLE SERVICE
Revision: 2007 April2007 M35/M45
ON-VEHICLE SERVICEPFP:00000
Adjustment of Steering Angle Sensor Neutral PositionNFS000Q4
In case of doing work that applies to the list below, make sure to adjust neutral position of steering angle sen-
sor before running vehicle.
×: Required
–: Not required
CAUTION:
To adjust neutral position of steering angle sensor, make sure to use CONSULT-II.
(Adjustment cannot be done without CONSULT-II.)
1. Stop vehicle with front wheels in straight-ahead position.
2. Perform “CONSULT-II Starting Procedure”. Refer to GI-38, "
CONSULT-II Start Procedure" .
3. Turn ignition switch ON and touch the CONSULT-II screen in the order of “ABS”, “WORK SUPPORT” and
“ST ANG SEN ADJUSTMENT”.
4. Touch “START”.
CAUTION:
Do not touch steering wheel while adjusting steering angle
sensor.
5. After approximately 10 seconds, touch “END”. (After approxi-
mately 60 seconds, it ends automatically.)
6. Turn ignition switch OFF, then turn it ON again.
CAUTION:
Be sure to perform above operation.
7. Run vehicle with front wheels in straight-ahead position, then
stop.
8. Select “DATA MONITOR”, “ECU INPUT SIGNALS”, and “STR ANGLE SIG” on CONSULT-II screen. Then
make sure “STR ANGLE SIG” is within 0±2.5°. If value is more than specification, repeat steps 1 to 7.
9. Erase memory of ABS actuator and electric unit (control unit) and ECM. ABS actuator and electric unit
(control unit): Refer to BRC-24, "
ERASE MEMORY" . ECM: Refer to EC-90, "TROUBLE DIAGNOSIS"
(VQ35DE), EC-792, "TROUBLE DIAGNOSIS" (VK45DE).
10. Turn ignition switch OFF.
Situation Adjustment of Steering Angle Sensor Neutral Position
Removing/Installing ABS actuator and electric unit (control unit)−
Replacing ABS actuator and electric unit (control unit)×
Removing/Installing steering angle sensor×
Removing/Installing steering components×
Removing/Installing suspension components×
Change tires to new ones–
Tire rotation–
Adjusting wheel alignment×
SFIA0793E

SYSTEM DESCRIPTION
BRC-7
[VDC/TCS/ABS]
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BRC
Revision: 2007 April2007 M35/M45
SYSTEM DESCRIPTIONPFP:00000
System DiagramNFS000Q5
FunctionsNFS000Q6
ABS

Anti-Lock Brake System is a function that detects wheel revolution while braking, electronically controls
braking force, and prevents wheel locking during sudden braking. It improves handling stability and
maneuverability for avoiding obstacles.

Electrical system diagnosis by CONSULT-II is available.
EBD

Electronic Brake force Distribution is a following function. ABS actuator and electric unit (control unit)
detects subtle slippages between the front and rear wheels during braking. Then it electronically controls
the rear braking force (brake fluid pressure) to reducing and reduces rear wheel slippage. Accordingly it
improves vehicle stability.

Electrical system diagnosis by CONSULT-II is available.
1. Electric line 2. Brake hydraulic line 3. ECM
4. TCM 5. Steering angle sensor 6. Warning lamp, indicator lamp
(combination meter)
7. AWD control unit
(AWD models)8. ICC sensor integrated unit
(with ICC)9. RAS control unit
(with RAS)
10. Injector operation signal 11. CAN communication 12. Front RH wheel sensor
13. Front LH wheel sensor 14. Master cylinder 15. ABS actuator and electric unit (con-
trol unit)
16. VDC OFF switch 17. Yaw rate/side G sensor 18. Rear RH wheel sensor
19. Rear LH wheel sensor
SFIA2722J

BRC-8
[VDC/TCS/ABS]
SYSTEM DESCRIPTION
Revision: 2007 April2007 M35/M45
TCS

Traction Control System is a function that electronically controls engine torque, brake fluid pressure and
A/T gear position to ensure the optimum slippage ratio at drive wheels by computing wheel speed signals
from 4 wheel sensors. When ABS actuator and electric unit (control unit) detects a spin at drive wheels
(rear wheels), it compares wheel speed signals from all 4 wheels. At this time, LH and RH rear brake fluid
pressure are controlled, while fuel being cut to engine and throttle valve being closed to reduce engine
torque by the control unit. Further more, throttle position is continuously controlled to ensure the optimum
engine torque at all times.

During TCS operation, it informs driver of system operation by flashing SLIP indicator lamp.

Electrical system diagnosis by CONSULT-II is available.
VDC

Vehicle Dynamics Control system detects driver's steering operation amount and brake pedal travel from
steering angle sensor and pressure sensor. Using information from yaw rate/side G sensor and wheel
sensor, VDC judges driving condition (conditions of under steer and over steer) to improve vehicle driving
stability by controlling brake application to 4 wheels and engine output.

During VDC operation, it informs driver of system operation by flashing SLIP indicator lamp.

Electrical system diagnosis by CONSULT-II is available.
ECD
Receives deceleration degree commandment value signal from ICC sensor integrated unit, and controls brake
fluid pressure with the motor [built-in ABS actuator and electric unit (control unit)].
Operation That Is Not "System Error" NFS000Q7
ABS

When starting engine or just after starting vehicle, brake pedal may vibrate or the motor operating sound
may be heard from engine room. This is a normal states of the operation check.

During ABS operation, brake pedal lightly vibrates and a mechanical sound may be heard. This is normal.

Stopping distance may be longer than that of vehicles without ABS when vehicle drives on rough, gravel,
or snow-covered (fresh, deep snow) roads.
TCS

Depending on road circumstances, driver may have a sluggish feel. This is normal, because optimum
traction has highest priority under TCS operation.

When vehicle is passing through a road where surface friction varies, downshifting or depressing acceler-
ator pedal fully may activate TCS temporarily.
VDC

During VDC operation, body and brake pedal lightly vibrate and mechanical sounds may be heard. This is
normal.

If vehicle is rotated on turn table, or rolled and rocked on ship, ABS warning lamp, VDC OFF indicator
lamp, and SLIP indicator lamp may turn on. In this case, start engine on normal road again. If ABS warn-
ing lamp, VDC OFF indicator lamp, and SLIP indicator lamp turn off after restart, it is normal.

When starting TCS or VDC under rapid acceleration or hard turn, operating sound by brake pedal is gen-
erated. However, this is not malfunction. This is because TCS and VDC are functioning normally.

VDC may not operate normally or ABS warning lamp, VDC OFF indicator lamp and SLIP indicator lamp
may turn on when driving special roads with extremely steep slant (banks on circuit road and so on.) How-
ever, it is not malfunction when returning to a normal state after restarting the engine. In that case, be sure
to erase the memory of self-diagnosis. Refer to BRC-24, "
ERASE MEMORY" .

Yaw rate /side G sensor malfunction may occur under hard turn like spin turn, rapid acceleration turn, drift
run, etc., when VDC function is OFF (VDC OFF switch is turned on). It is not malfunction if it is possible to
return to a normal position after restarting engine. Then erase the memory of self-diagnosis. Refer to
BRC-24, "
ERASE MEMORY" .

VDC OFF indicator lamp and SLIP indicator lamp may simultaneously turn on when low tire pressure
warning lamp turns on. This is not a VDC system error but results from characteristic change of tires.

SYSTEM DESCRIPTION
BRC-9
[VDC/TCS/ABS]
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BRC
Revision: 2007 April2007 M35/M45
Hydraulic Circuit DiagramNFS000Q9
CAN CommunicationNFS000QA
SYSTEM DESCRIPTION
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" .
SFIA3049E

TROUBLE DIAGNOSIS
BRC-21
[VDC/TCS/ABS]
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MA
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BRC
Revision: 2007 April2007 M35/M45
Control Unit Input/Output Signal StandardNFS000RH
REFERENCE VALUE FROM CONSULT-II
CAUTION:
The display shows ABS actuator and electric unit (control unit) calculation data, so a normal value
might be displayed even in the event the output circuit (harness) is open or short-circuited.
Monitor item Display contentData monitor
ConditionReference value in nor-
mal operation
FR LH SENSOR
FR RH SENSOR
RR LH SENSOR
RR RH SENSORWheel speedVehicle stopped 0 [km/h (MPH)]
Vehicle running (Note 1)Nearly matches the
speedometer display
(± 10 % or less)
STOP LAMP SW Brake pedal operationWhen brake pedal is depressed ON
When brake pedal is not depressed OFF
BATTERY VOLTBattery voltage supplied to the ABS
actuator and electric unit (control unit)Ignition switch ON 10 – 16 V
GEAR Gear position determined by TCM1st gear
2nd gear
3rd gear
4th gear
5th gear1
2
3
4
5
SLCT LVR POSI A/T select lever positionP position
R position
N position
D positionP
R
N
D
OFF SW VDC OFF switchVDC OFF switch :ON
(When VDC OFF indicator lamp is ON)ON
VDC OFF switch :OFF
(When VDC OFF indicator lamp is OFF)OFF
YAW RATE SENYaw rate detected by yaw rate/side G
sensorWhen vehicle stop Approx. 0 d/s
When vehicle turning (–75 to 75 d/s)
4WD MODE MON
(Note 2)AWD activated Engine running AUTO
ACCEL POS SIG Throttle actuator opening/closing is dis-
played (linked with accelerator pedal)Accelerator pedal not depressed
(Engine stopped)0 %
Depress accelerator pedal
(Engine stopped)0 - 100 %
SIDE G-SENSOR Transverse G detected by side G sensorVehicle stopped
Approx. 0 m/s
2
Vehicle turning rightNegative value
(m/s2 )
Vehicle turning leftPositive value
(m/s
2 )
STR ANGLE SIGSteering angle detected by steering
angle sensorStraight-ahead Approx. 0°
Steering wheel turned –720 to 720°
PRESS SENSORBrake fluid pressure detected by pres-
sure sensorWith ignition switch turned ON and brake
pedal releasedApprox. 0 bar
With ignition switch turned ON and brake
pedal depressed–40 to 300 bar
ENGINE RPM Engine speedWith engine stopped 0 rpm
Engine runningAlmost in accordance
with tachometer display

BRC-22
[VDC/TCS/ABS]
TROUBLE DIAGNOSIS
Revision: 2007 April2007 M35/M45
FLUID LEV SW Brake fluid level switchBrake fluid level switch ON ON
Brake fluid level switch OFF OFF
PARK BRAKE SW Parking brake switchParking brake switch is active ON
Parking brake switch is inactive OFF
FR RH IN SOL
FR RH OUT SOL
FR LH IN SOL
FR LH OUT SOL
RR RH IN SOL
RR RH OUT SOL
RR LH IN SOL
RR LH OUT SOLOperation status of all solenoid valve Actuator (solenoid valve) is active
(“ACTIVE TEST” with CONSULT-II) or
actuator relay is inactive (in fail-safe
mode)ON
When the actuator (solenoid valve) is not
active and actuator relay is active (igni-
tion switch ON)OFF
MOTOR RELAY Motor and motor relay operationWhen the motor relay and motor are
operatingON
When the motor relay and motor are not
operatingOFF
ACTUATOR RLY
(Note 3)Actuator relay operationWhen the actuator relay is operating ON
When the actuator relay is not operating OFF
ABS WARN LAMPABS warning lamp
(Note 4)When ABS warning lamp is ON ON
When ABS warning lamp is OFF OFF
OFF LAMPVDC OFF indicator lamp
(Note 4)When VDC OFF indicator lamp is ON ON
When VDC OFF indicator lamp is OFF OFF
SLIP LAMPSLIP indicator lamp
(Note 4)When SLIP indicator lamp is ON ON
When SLIP indicator lamp is OFF OFF
4WD FAIL REQ
(Note 2)AWD control unit fail-safe signal When AWD control unit is fail-safe mode ON
When AWD control unit is normal OFF
SNOW MODE SW Snow mode switchWhen snow mode switch is ON ON
When snow mode switch is OFF OFF
BST OPER SIG Not applied but displayed — OFF
M-MODE SIG Manual mode operationWhen the manual mode is active ON
When the manual mode is inactive OFF
EBD SIGNAL EBD operationEBD is active ON
EBD is inactive OFF
ABS SIGNAL ABS operationABS is active ON
ABS is inactive OFF
TCS SIGNAL TCS operationTCS is active ON
TCS is inactive OFF
VDC SIGNAL VDC operationVDC is active ON
VDC is inactive OFF
EBD FAIL SIG EBD fail-safe signalIn EBD fail-safe ON
EBD is normal OFF
ABS FAIL SIG ABS fail-safe signalIn ABS fail-safe ON
ABS is normal OFF
TCS FAIL SIG TCS fail-safe signalIn TCS fail-safe ON
TCS is normal OFF Monitor item Display contentData monitor
ConditionReference value in nor-
mal operation