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-16
[RAS]
SYSTEM DESCRIPTION
Revision: 2006 January2006 M35/M45
SYSTEM DESCRIPTIONPFP:00000
ComponentsNGS000E8
RAS (Rear Active Steer) FunctionNGS000E9
A. RAS control unit B. Model following control C. Target vehicle dynamics model
D. Rear wheel steering angle com-
mand value operationE. Rear wheel steering angle servo F. Vehicle speed signal (CAN)
G. Steering angle signal (CAN) H. Vehicle speed sensor I. Steering angle sensor
J. RAS actuator assembly
SGIA1241E
Part name Function
RAS control unit
Calculate the vehicle speed signal from CAN communication and the signals from steering
angle sensor and rear wheel steering angle sensor by a computer, and then control the rear
wheel steering angle.
Fail-safe function is activated when the electrical system is malfunctioning. The output signal
to the actuator is turned OFF during this mode. At that time, the RAS warning lamp illumi-
nates and indicates the system is malfunctioning.
It performs the communication control function with other control units via CAN communica-
tion.
This enables system diagnosis with CONSULT-II.
RAS actuatorThe efficiency of the rear wheel steer improves by locating the electric motor actuator into the
lower link of rear suspension.
Steering angle sensor
Measure the steering angle and send it to RAS control unit via CAN communication.
It is shared with the steering angle sensor for VDC.
Rear wheel steering angle sensor
It sends the rear wheel steering angle status to RAS control unit. The accuracy of rear wheel
steer improves by comparing the vehicle speed signal from CAN communication with the
rear wheel steering angle target value calculated from the wheel angle sensor signal, and it
controls them.
There are 2 types of rear wheel steering angle sensors (main/sub). If one of them is malfunc-
tioning, the other operates the fail-safe mode and stops the control.
RAS warning lamp
It turns on when the fail-safe function is operated and indicates that a RAS control malfunc-
tion has occurred.
It turns on when ignition switch turns on and turns off after the engine is started.
It indicates the suspect system by blinking when performing the self-diagnosis (without CON-
SULT-II).
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
TROUBLE DIAGNOSIS
STC-27
[RAS]
C
D
E
F
H
I
J
K
L
MA
B
STC
Revision: 2006 January2006 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.
Monitor itemDATA MONITOR
Malfunction inspection
checklist
Condition Reference values
VHCL SPEED SE (km/h)Ignition switch ON or engine
running Almost in accordance with the speed-
ometer display. It is not a malfunction,
through it might not be corresponding
just after ignition switch is turned ON.STC-38, "
Inspection 4:
Vehicle Speed Signal"
STEERING ANG ()Turning steering wheel clock-
wise or counterclockwise.Displays the angle when the steering
wheel turns from the neutral positionSTC-38, "
Inspection 5:
Steering Angle Signal
Malfunction"
ENGINE SPEED (rpm) Engine runningAlmost in accordance with tachometer
displaySTC-43, "
Inspection 8:
Engine Speed Signal
Malfunction"
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 ASTC-46, "Diagnosis
Chart by Symptom 2"
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 VSTC-40, "Inspection 6:
Rear Main Signal and
Rear Sub Signal Mal-
function"RR ST ANG- SUB (V)
RR ST ANG-VOL (V)
Ignition switch ON or engine
runningApprox. 5 VSTC-40, "
Inspection 6:
Rear Main Signal and
Rear Sub Signal Mal-
function"
C/U VOLTAGE (V) Battery voltage (Approx. 12 V)STC-35, "
Inspection 1:
RAS Control Unit Mal-
function"
MOTOR VOLTAGE (V) Battery voltage (Approx. 12V)STC-35, "
Inspection 2:
Motor Power Supply
System"
MOTOR CURRENT (A)Perform the ACTIVE TEST
and stroke the actuator.It is normal when there is the current
output at strokeSTC-35, "
Inspection 2:
Motor Power Supply
System"
MTR CRNT OPE (A)Turning steering wheel clock-
wise or counterclockwise
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 STC-37, "
Inspection 3:
RAS Motor Output
Malfunction"
STOP LAMP SWDepressing or releasing brake
pedalBrake pedal depressed: ONSTC-44, "
Inspection
10: Stop Lamp Switch
Harness"Brake pedal not depressed: OFF
RAS RELAY
Ignition switch ON or engine
runningIgnition switch ON: ONSTC-35, "
Inspection 2:
Motor Power Supply
System"
FAIL SAFE Not activatedSelf-diagnosis and
suspect system
inspection on DATA
MONITOR
WARNING LAMP (ON/OFF)RAS warning lamp ON: ON
RAS warning lamp OFF: OFFWarning lamp circuit
inspection
STC-28
[RAS]
TROUBLE DIAGNOSIS
Revision: 2006 January2006 M35/M45
CONSULT-II Function (RAS)NGS000EG
FUNCTION
CONSULT-II can display each self-diagnostic item using the diagnostic test modes shown following.
CONSULT-II SETTING PROCEDURE
Refer to GI-39, "CONSULT-II Start Procedure" .
SELF-DIAG RESULT MODE
Operation Procedure
1. Perform “CONSULT-II Start Procedure”. Refer to GI-39, "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
“CONTROL_UNIT (CAN) [U1010]”, inspect the CAN communication system.
Mode Function Reference
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
malfunctions.STC-30, "DATA MONITOR MODE"
CAN DIAG SUPPORT MNTRMonitors transmitting/receiving status of CAN communi-
cation.STC-31, "CAN Communication"
ACTIVE TESTSends command to RAS actuator to change output sig-
nals 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"
DTC code Diagnostic item Diagnostic item is detected when... Check items
C1923 STEERING_ANGLE_SEN [NO_CHANGE] (ꞏ a)While driving at 60 km/h (37 MPH)
or more, steering angle does not
change for a while.STC-38
C1924 STEERING_ANGLE_SEN [NO_NEUT_STATE] (ꞏ b)When driving some distance, no
neutral signal (ON signal) is input.STC-38
C1915 RR_ST_ANGLE_SENSOR [MAIN_SIGNAL] (ꞏ a)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] (ꞏ b)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, C1918 RR_ST_ANGLE_SENSOR [OFFSET_SIG1,2] (ꞏ c)An excessive difference has
occurred in the input values of main
sensor and sub sensor.STC-40
C1914 RR_ST_ANGLE_SENSOR [ABNORMAL_VOL] (ꞏ d)Higher or lower value compared to
the standard voltage.STC-40
C1921 MOTOR_OUTPUTNo engine speed is input for a cer-
tain time.STC-43
C1911 MOTOR_VOLTAGE [LOW_VOLTAGE] (ꞏ a)The motor power supply voltage is
lower than ignition power supply
voltage with RAS motor relay ON.STC-35
STC-32
[RAS]
TROUBLE DIAGNOSIS
Revision: 2006 January2006 M35/M45
For Fast and Accurate Trouble DiagnosisNGS000EN
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 is 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.
Is the battery voltage proper?
Check each connector connection condition.
Check the following items while driving the vehicle
Conditions when the error occurred (5W 1H).
Is the engine is normal?
Basic InspectionNGS000EO
BASIC INSPECTION 1: 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.
BASIC INSPECTION 2: RAS WARNING LAMP INSPECTION
1. Make sure RAS warning lamp turns on when ignition switch is turned ON.
If it does not turn on, refer to STC-33, "Trouble Diagnosis Chart" .
2. Make sure that RAS warning lamp turns off when the engine is started after ignition switch is turned ON. If
it does not turn off, perform self-diagnosis. Refer to STC-28, "
SELF-DIAG RESULT MODE" .
3. Always erase DTC memory after completing self-diagnosis. Refer to STC-29, "
How to Erase Self-Diag-
nostic Results" .
BASIC INSPECTION 3: RAS CONTROL UNIT POWER SUPPLY CIRCUIT AND GROUND CIR-
CUIT INSPECTION
1. CHECK RAS CONTROL UNIT CONNECTOR
Turn ignition switch OFF, disconnect RAS control unit harness connector, and check terminal for deformation,
disconnection, looseness, etc.
OK or NG
OK >> GO TO 2.
NG >> Poor connection of connector terminal. Repair or replace the terminal.
2. CHECK RAS CONTROL UNIT GROUND CIRCUIT
1. Disconnect RAS control unit harness connector B127, and then
check continuity between RAS control unit harness connector
B127 and ground.
OK or NG
OK >> GO TO 3.
NG >> Ground circuit open or shorted. Repair or replace any
inoperative parts. Terminal 34 – Ground : Continuity
SGIA1244E
TROUBLE DIAGNOSIS
STC-33
[RAS]
C
D
E
F
H
I
J
K
L
MA
B
STC
Revision: 2006 January2006 M35/M45
3. CHECK RAS CONTROL UNIT POWER SUPPLY CIRCUIT
Turn ignition switch ON, and then check voltage between RAS con-
trol unit harness connector B127 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.
Trouble Diagnosis ChartNGS000EP
SELF-DIAGNOSIS
Terminal 27 – Ground : Battery voltage (Approx. 12 V)
SGIA1245E
Item
Reference Self-diagnosis function CONSULT-II
DTC
(warning
lamp blinks)Diagnosis item Diagnosis item
11 Control unit CONTROL_UNIT [ABNORMAL 1 - 9]STC-35
12 Motor power supplyMOTOR_VOLTAGE [LOW_VOLTAGE] (ꞏ a)
STC-35MOTOR_VOLTAGE [BAD_OBSTRCT] (ꞏ b)
13 Motor outputMOTOR_OUTPUT [ABNORMAL_SIG] (ꞏ a)
STC-37
MOTOR_OUTPUT [REV_CURRENT] (ꞏ c)
MOTOR_OUTPUT [NO_CURRENT] (ꞏ d)
MOTOR_OUTPUT [OVERCURRENT] (ꞏ e)
MOTOR_OUTPUT [MOTOR_LOCK] (ꞏ b)
21 Vehicle speed signal VEHICLE_SPEED_SEN [NO_SIGNAL]STC-38
22 Steering angle signalSTEERING_ANGLE_SEN [NO_CHANGE] (ꞏ a)
STC-38STEERING_ANGLE_SEN [NO_NEUT_STATE] (ꞏ b)
STEERING_ANGLE_SEN [NO_SIGNAL]
STEERING_ANGLE_SEN
24 Rear wheel steering angle (main)RR_ST_ANGLE_SENSOR [MAIN_SIGNAL] (ꞏ a)
STC-40
RR_ST_ANGLE_SENSOR [ABNORMAL_VOL] (ꞏ d)
RR_ST_ANGLE_SENSOR [OFFSET_SIG 1, 2] (ꞏ c)
25 Rear wheel steering angle (sub)RR_ST_ANGLE_SENSOR [SUB_SIGNAL] (ꞏ b)
RR_ST_ANGLE_SENSOR [ABNORMAL_VOL] (ꞏ d)
RR_ST_ANGLE_SENSOR [OFFSET_SIG 1, 2] (ꞏ c)
26 VDC VDCSTC-42
27 Engine speed signal MOTOR_OUTPUTSTC-43
— CAN COMM CIRCUIT
STC-43
— CONTROL UNIT
STC-34
[RAS]
TROUBLE DIAGNOSIS
Revision: 2006 January2006 M35/M45
DIAGNOSIS CHART BY SYMPTOM
Symptom Reference
It is not entering the self-diagnosis mode.STC-32, "
BASIC INSPECTION 3: RAS CONTROL UNIT POWER
SUPPLY CIRCUIT AND GROUND CIRCUIT INSPECTION"
STC-44, "Inspection 10: Stop Lamp Switch Harness"
STC-44, "Inspection 11: RAS Warning Lamp Harness"
RAS warning lamp does not turn on with ignition switch ON.STC-32, "
BASIC INSPECTION 3: RAS CONTROL UNIT POWER
SUPPLY CIRCUIT AND GROUND CIRCUIT INSPECTION"
STC-44, "Inspection 11: RAS Warning Lamp Harness"
RAS warning lamp turns on with ignition switch ON. It does
not turn off even if the engine is started.STC-32, "
Basic Inspection"
STC-28, "SELF-DIAG RESULT MODE"
STC-31, "Diagnosis Procedure with Self-Diagnosis Function (With-
out CONSULT-II)"
RAS warning lamp may turn on after the engine is started.STC-28, "SELF-DIAG RESULT MODE"
The steering force does not change smoothly according to
the vehicle speed.STC-46, "Diagnosis Chart by Symptom 2"
Noise
STC-28, "SELF-DIAG RESULT MODE"
STC-31, "Diagnosis Procedure with Self-Diagnosis Function (With-
out CONSULT-II)"
STC-14, "INSPECTION AFTER DISASSEMBLY"
Malfunction other than aboveSTC-46, "Diagnosis Chart by Symptom 1"