TROUBLE DIAGNOSIS
STC-9
[EPS]
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Revision: 2007 April2007 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, "
Checking Fluid Leakage" .
Is the fluid level proper? Refer to PS-8, "Checking Fluid Level" .
Is the wheel alignment adjusted properly? Refer to FSU-6, "Wheel Alignment Inspection" (2WD), FSU-24,
"Wheel Alignment Inspection" (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: 2007 April2007 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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Revision: 2007 April2007 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 wheel turning force 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
TROUBLE DIAGNOSIS
STC-19
[RAS]
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Revision: 2007 April2007 M35/M45
Component Parts LocationNGS000EC
A. RAS warning lamp B. Steering angle sensor C. RAS control unit
D. RAS motor relay E. RAS motor F. Rear wheel steering angle sensor
G. Noise suppressor
SGIA1053J
STC-32
[RAS]
TROUBLE DIAGNOSIS
Revision: 2007 April2007 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, "
Checking Fluid Leakage" .
Is the fluid level proper? Refer to PS-8, "Checking Fluid Level" .
Is the wheel alignment is adjusted properly? Refer to FSU-6, "Wheel Alignment Inspection" (2WD), FSU-
24, "Wheel Alignment Inspection" (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 B476, and then
check continuity between RAS control unit harness connector
B476 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 should exit.
SGIA1244E
TROUBLE DIAGNOSIS
STC-33
[RAS]
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Revision: 2007 April2007 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 B476 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 RAS control unitCONTROL UNIT [ABNORMAL1] [C1900]
STC-35
CONTROL UNIT [ABNORMAL2] [C1901]
CONTROL UNIT [ABNORMAL3] [C1905]
CONTROL UNIT [ABNORMAL5] [C1906]
CONTROL UNIT [ABNORMAL4] [C1907]
CONTROL UNIT [ABNORMAL7] [C1908]
CONTROL UNIT [ABNORMAL6] [C1909]
CONTROL UNIT [ABNORMAL8] [C1922]
CONTROL UNIT [ABNORMAL5] [C1927]
CONTROL UNIT [ABNORMAL9] [C1928]
12 Motor power supplyMOTOR VOLTAGE [LOW VOLTAGE] [C1911]
STC-35
MOTOR VOLTAGE [BAD OBSTRCT] [C1912]
13 Motor outputMOTOR OUTPUT [ABNORMAL SIG] [C1913]
STC-37
MOTOR OUTPUT [REV CURRENT] [C1902]
MOTOR OUTPUT [NO CURRENT] [C1903]
MOTOR OUTPUT [OVERCURRENT] [C1904]
MOTOR OUTPUT [MOTOR LOCK] [C1910]
21 Vehicle speed signal VEHICLE SPEED SEN [NO SIGNAL] [C1919]STC-38
22 Steering angle signalSTEERING ANGLE SEN [NO CHANGE] [C1923]
STC-39STEERING ANGLE SEN [NO NEUT STATE] [C1924]
STEERING ANGLE SEN [NO SIGNAL] [C1920]
STEERING ANGLE SEN [C1926]
TROUBLE DIAGNOSIS
STC-37
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Revision: 2007 April2007 M35/M45
5. CHECK RAS CONTROL UNIT OUTPUT SIGNAL
1. Connect RAS control unit harness connector B476 and RAS
motor relay harness connector B480.
2. Check voltage between RAS motor relay harness connector
B480 and ground.
OK or NG
OK >> Check RAS motor relay separately from other parts.
Refer to STC-50, "
RAS MOTOR RELAY" .
NG >> RAS control unit malfunction (replacement)
Inspection 3: RAS Motor Output MalfunctionNGS000ES
1. CHECK RAS CONTROL UNIT CONNECTOR
1. Turn ignition switch OFF, disconnect RAS control unit harness connector and RAS motor harness connec-
tor, and check terminal for deformation, disconnection, looseness, etc.
2. Reconnect harness connector securely, and perform self-diagnosis.
With CONSULT-II
Without CONSULT-II
Is above displayed on self-diagnosis display?
YES >> GO TO 2.
NO >> Connector terminal connection is loose, damaged, open, or shorted. Repair or replace the termi-
nal.
2. CHECK RAS MOTOR RESISTANCE
1. Turn ignition switch OFF, and disconnect RAS motor harness connector B463.
2. Check the resistance RAS motor connector.
OK or NG
OK >> GO TO 3.
NG >> RAS motor malfunction. Replace RAS motor.1–Ground
Ignition switch ON : Battery voltage (Approx. 12 V)
Ignition switch OFF : Approx. 0V
SGIA1267E
Self-diagnosis results
MOTOR OUTPUT [ABNORMAL SIG] [C1913]
MOTOR OUTPUT [REV CURRENT] [C1902]
MOTOR OUTPUT [NO CURRENT] [C1903]
MOTOR OUTPUT [OVERCURRENT] [C1904]
MOTOR OUTPUT [MOTOR LOCK] [C1910]
DTC (warning lamp blinks)
13
Terminal 1 – 2 : Approx. 0.6 Ω
SGIA1268E
STC-48
[RAS]
TROUBLE DIAGNOSIS
Revision: 2007 April2007 M35/M45
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.
4. CHECK POWER STEERING SOLENOID VALVE POWER SUPPLY CIRCUIT
Check continuity between RAS control unit harness connector B476
(A) and power steering solenoid valve harness connector F25
(VQ35DE), E211 (VK45DE) (B).
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 F25
(VQ35DE), E211 (VK45DE) and then make sure that the operating
sound (clicking sound) is heard.
OK or NG
OK >> Perform steering wheel turning force inspection. Refer
to PS-10, "
CHECKING STEERING WHEEL TURNING
FORCE" .
NG >> Power steering solenoid valve is inoperating. Replace it.
7. CHECK SELF-DIAGNOSIS RESULTS
Perform RAS self-diagnosis.
With CONSULT-II: STC-28, "SELF-DIAG RESULT MODE"
Without CONSULT-II: STC-31, "Diagnosis Procedure with Self-Diagnosis Function (Without CONSULT-
II)"
Are malfunctioning items displayed in self-diagnosis results?
YES >> Repair or replace any malfunctioning items.
NO >> RAS control unit malfunction. Replace it.
RAS C/U Power steering solenoid valve Continuity
Terminal 36 Terminal 1 Yes
SGIA1652E
Terminal 2 – Ground : Continuity should exist.
SGIA1283E
Terminal 1 (+) - 2 (-) : Operating sound is heard.
SGIA1284E