STC-2Revision: 2006 January2006 M35/M45 Inspection 2: Motor Power Supply System ............. 35
Inspection 3: RAS Motor Output Malfunction ......... 37
Inspection 4: Vehicle Speed Signal ........................ 38
Inspection 5: Steering Angle Signal Malfunction .... 38
Inspection 6: Rear Main Signal and Rear Sub Signal
Malfunction ............................................................. 40
Inspection 7: VDC Malfunction ............................... 42
Inspection 8: Engine Speed Signal Malfunction ..... 43
Inspection 9: CAN Communication System Mal-
function ................................................................... 43Inspection 10: Stop Lamp Switch Harness ............. 44
Inspection 11: RAS Warning Lamp Harness ........... 44
Diagnosis Chart by Symptom 1 .............................. 46
Diagnosis Chart by Symptom 2 .............................. 46
Check RAS Static/Dynamic Characteristics ............ 48
Component Parts Inspection ................................... 49
RAS MOTOR RELAY ........................................... 49
RAS MOTOR ....................................................... 49
REAR WHEEL STEERING ANGLE SENSOR .... 49
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
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-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]
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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