2007 INFINITI M35 Steering Angle Sensor Circuit

BRC-1
BRAKE CONTROL SYSTEM
F BRAKES
CONTENTS
C
D
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G
H
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J
K
L
M
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

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.

TROUBLE DIAGNOSIS
BRC-21
[VDC/TCS/ABS]
C
D
E
G
H
I
J
K
L
MA
B
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-26
[VDC/TCS/ABS]
TROUBLE DIAGNOSIS
Revision: 2007 April2007 M35/M45
C1120 FR LH IN ABS SOLWhen the control unit detects a malfunction in the front left inlet sole-
noid circuit.
BRC-39, "
Sole-
noid, VDC
Change-Over
Valve and Actua-
tor Relay Circuit"
C1121 FR LH OUT ABS SOLWhen the control unit detects a malfunction in the front left outlet sole-
noid circuit.
C1122 FR RH IN ABS SOLWhen the control unit detects a malfunction in the front right inlet sole-
noid circuit.
C1123 FR RH OUT ABS SOLWhen the control unit detects a malfunction in the front right outlet sole-
noid circuit.
C1124 RR LH IN ABS SOLWhen the control unit detects a malfunction in the rear left inlet solenoid
circuit.
C1125 RR LH OUT ABS SOLWhen the control unit detects a malfunction in the rear left outlet sole-
noid circuit.
C1126 RR RH IN ABS SOLWhen the control unit detects a malfunction in the rear right inlet sole-
noid circuit.
C1127 RR RH OUT ABS SOLWhen the control unit detects a malfunction in the rear right outlet sole-
noid circuit.
C1130 ENGINE SIGNAL 1
Major engine components are malfunctioning.BRC-36, "
Engine
System"
C1131 ENGINE SIGNAL 2
C1132 ENGINE SIGNAL 3
C1133 ENGINE SIGNAL 4
C1136 ENGINE SIGNAL 6
C1137 RAS CIRCUIT When RAS control unit is malfunctioning.BRC-47, "
RAS
Control Unit Cir-
cuit (With RAS)"
C1142 PRESS SEN CIRCUIT Pressure sensor signal line is open or shorted, or pressure sensor is
malfunctioning.BRC-40, "
Pres-
sure Sensor Cir-
cuit"
C1143 ST ANG SEN CIRCUIT Neutral position of steering angle sensor is dislocated, or the steering
angle sensor is malfunctioning.BRC-41, "
St e e r -
ing Angle Sensor
Circuit"
C1144 ST ANG SEN SIGNAL Neutral position correction of steering angle sensor is not finished.BRC-6, "
Adjust-
ment of Steering
Angle Sensor
Neutral Position"
C1145 YAW RATE SENSOR Yaw rate sensor is malfunctioning, or the yaw rate sensor signal line is
open or shorted.BRC-44, "Ya w
Rate/Side G
Sensor Circuit"C1146 SIDE G-SEN CIRCUITSide G sensor is malfunctioning, or circuit of side G sensor is open or
shorted.
C1147 USV LINE [FL-RR]VDC switch-over solenoid valve (USV1) on the primary side is open cir-
cuit or shorted, or the control line is open or shorted to the power supply
or the ground.
BRC-39, "
Sole-
noid, VDC
Change-Over
Valve and Actua-
tor Relay Circuit"
C1148 USV LINE [FR-RL]VDC switch-over solenoid valve (USV2) on the secondary side is open
circuit or shorted, or the control line is open or shorted to the power
supply or the ground.
C1149 HSV LINE [FL-RR]VDC switch-over solenoid valve (HSV1) on the primary side is open cir-
cuit or shorted, or the control line is open or shorted to the power supply
or the ground.
C1150 HSV LINE [FR-RL]VDC switch-over solenoid valve (HSV2) on the secondary side is open
circuit or shorted, or the control line is open or shorted to the power
supply or the ground.
C1153 EMERGENCY BRAKEWhen ABS actuator and electric unit (control unit) is malfunctioning.
(Pressure increase is too much or too little)BRC-36, "
ABS
Actuator and
Electric Unit
(Control Unit)"
Code Display item Malfunction detecting condition Check item

TROUBLE DIAGNOSIS
BRC-27
[VDC/TCS/ABS]
C
D
E
G
H
I
J
K
L
MA
B
BRC
Revision: 2007 April2007 M35/M45
Note 1: After completing repairs of shorted sensor circuit, when ignition switch is turned ON, ABS warning lamp turns on. Make sure that
ABS warning lamp turns off while driving vehicle at 30 km/h (19 MPH) or more for approximately 1 minute according to self-diagnosis
procedure. In addition, if wheel sensor 2 is displayed for wheels, check wheel sensor circuit and also check control unit power voltage.
Note 2: When malfunctions are detected in several systems, including CAN communication circuit [U1000], troubleshoot CAN communi-
cation circuit. Refer to BRC-48, "
CAN Communication Circuit" . C1155 BR FLUID LEVEL LOWBrake fluid level is low or communication line between the ABS actuator
and electric unit (control unit) and brake fluid level switch is open or
shorted. BRC-46, "
Brake
Fluid Level
Switch Circuit"
C1156 ST ANG SEN COM CIR CAN communication circuit or steering angle sensor is malfunctioning.BRC-48, "
CAN
Communication
Circuit"
C1170 VARIANT CODING In a case where VARIANT CODING is different.BRC-36, "
ABS
Actuator and
Electric Unit
(Control Unit)"
C1185 ACC CONT ICC sensor integrated unit internal malfunction.BRC-48, "
ICC
Sensor Inte-
grated Unit Cir-
cuit (With ICC)"
U1000 CAN COMM CIRCUITWhen ABS actuator and electric unit (control unit) is not transmitting or
receiving CAN communication signal for 2 seconds or more.BRC-48, "
CAN
Communication
Circuit"
(Note 2)
U1100 ACC COMM CIRCUITWhen there is a malfunction in the CAN communication circuit or ICC
sensor integrated unit.BRC-48, "
CAN
Communication
Circuit"
Code Display item Malfunction detecting condition Check item

BRC-32
[VDC/TCS/ABS]
TROUBLE DIAGNOSIS
Revision: 2007 April2007 M35/M45
For Fast and Accurate DiagnosisNFS000QJ
PRECAUTIONS FOR DIAGNOSIS

Before performing diagnosis, always read General Information (GI) to confirm general precautions. Refer
to GI-4, "
General Precautions" .

If steering angle sensor, steering system parts, suspension system parts, ABS actuator and electric unit
(control unit) or tires have been replaced, or if wheel alignment has been adjusted, be sure to adjust neu-
tral position of steering angle sensor before driving. Refer to BRC-6, "
Adjustment of Steering Angle Sen-
sor Neutral Position" .

After diagnosis is finished, be sure to erase memory. Refer to BRC-24, "ERASE MEMORY" .

When checking continuity and voltage between unit, be sure to check for disconnection, looseness, bend,
or collapse of connector terminals. If any malfunction is found, repair or replace connector terminals.

For intermittent symptoms, possible cause is malfunction in harness, harness connector, or terminals.
Move harness, harness connector, and terminals to check for poor connections.

If a circuit tester is used for the check, be careful not to forcibly extend any connector terminal.

The following symptoms may be caused by normal operations.
Symptom Symptom description Result
Motor operation soundThis is sound of motor inside VDC actuator. Slight sound may occur
during VDC, TCS, and ABS operation.
Normal
Just after engine starts, the motor operating sound may be heard.
This is a normal condition of the system operation check.
System operation check soundWhen engine starts, slight “click” sound may be heard from engine
room. This is normal and is part of system operation check.Normal
VDC/TCS operation
(SLIP indicator lamp ON)TCS may activate momentarily if wheel speed changes when driving
over location where friction varies, when downshifting, or when fully
depressing accelerator pedal.Normal
Cancel the VDC/TCS
function for the inspec-
tion on a chassis dyna-
mometer. When checking speed meter etc. With a 2-wheel-drive chassis dyna-
mometer, vehicle speed is not increased by pressing down on the
accelerator.
ABS operation
(Longer stopping distance)On roads with low friction, such as snowy roads or gravel roads, vehi-
cles with ABS may require a longer stopping distance. Therefore,
when driving on such roads, avoid overconfidence and keep speed
sufficiently low.Normal
Insufficient feeling of accelerationDepending on road conditions, driver may feel that feeling of acceler-
ation is insufficient. This is because traction control, which controls
engine and brakes to achieve optimal traction, has the highest priority
(for safety). As a result, there may be times when acceleration is
slightly less than usual for the same accelerator pedal operation.Normal

TROUBLE DIAGNOSIS FOR SYSTEM
BRC-41
[VDC/TCS/ABS]
C
D
E
G
H
I
J
K
L
MA
B
BRC
Revision: 2007 April2007 M35/M45
4. CHECK STOP LAMP SWITCH CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect stop lamp switch connector E124 and ABS actuator and electric unit (control unit) connector
E30.
3. Check continuity between stop lamp switch harness connector and ABS actuator and electric unit (control
unit) harness connector.
OK or NG
OK >> GO TO 5.
NG >> Open or short in harness between stop lamp switch and ABS actuator and electric unit (control
unit). Repair or replace applied harness.
5. CHECK PRESSURE SENSOR
1. Connect ABS actuator and electric unit (control unit) connector.
2. Perform “DATA MONITOR” of the “PRESS SENSOR” to check if the status is normal.
OK or NG
OK >> INSPECTION END
NG >> If the pressure sensor is damaged or malfunctioning, replace the ABS actuator and electric unit
(control unit).
Steering Angle Sensor CircuitNFS000QS
INSPECTION PROCEDURE
1. CHECK SELF-DIAGNOSIS RESULTS
Check self-diagnosis results.
Is above displayed on the self-diagnosis display?
YES >> GO TO 2.
NO >> INSPECTION END
2. CHECK CONNECTOR
1. Turn ignition switch OFF and disconnect ABS actuator and electric unit (control unit) connector E30,
check terminal for deformation, disconnection, looseness, and so on. If any malfunction is found, repair or
replace terminal.
2. Reconnect connector and perform self-diagnosis.
OK or NG
OK >> INSPECTION END
NG >> GO TO 3.
ABS actuator and electric unit (control unit) Stop lamp switch Continuity
30 4 Yes
Condition Data monitor display
When brake pedal is depressed.−40 to 300 bar
When brake pedal is released. Approx. 0 bar
Self-diagnosis results
ST ANG SEN CIRCUIT