steering NISSAN TEANA 2008 Service Manual

STC-8
< COMPONENT DIAGNOSIS >
POWER STEERING SOLENOID VALVE
YES >> INSPECTION END
NO >> Repair or replace damaged parts.
Component InspectionINFOID:0000000003893530
1.CHECK POWER STEERING SOLENOID VALVE
1. Turn the ignition switch OFF.
2. Disconnect power steering solenoid valve harness connector.
3. Check resistance between power steering solenoid valve connector terminals.
4. Check power steering solenoid valve by listening for its operation sound while applying battery voltage to
power steering solenoid valve connector E52 terminals 1 (positive) and 2 (negative).
Is the inspection result normal?
YES >> INSPECTION END
NO >> Replace gear-sub assembly. Refer to ST-18, "
Exploded View".
Power steering solenoid valve
Resistance (Approx.)
Connector Terminal
E52 1 2 4 – 6 Ω

ENGINE SPEED SIGNAL CIRCUIT
STC-9
< COMPONENT DIAGNOSIS >
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ENGINE SPEED SIGNAL CIRCUIT
DescriptionINFOID:0000000003893531
ECM sends engine speed signal to power steering control unit.
Diagnosis ProcedureINFOID:0000000003893532
1.PERFORM ECM SELF-DIAGNOSIS
With CONSULT-III
1. Turn the ignition switch ON.
Perform ECM self-diagnosis. Refer to EC-113, "
CONSULT-III Function".
Is any DTC detected?
YES >> Check the DTC.
NO >> GO TO 2.
2.CHECK HARNESS BETWEEN ECM AND POWER STEERING CONTROL UNIT
1. Turn the ignition switch OFF.
2. Disconnect ECM harness connectors.
3. Disconnect power steering control unit harness connector.
4. Check continuity between ECM harness connector and power steering control unit harness connector.
5. Check continuity between power steering control unit harness connector and ground.
Is the inspection result normal?
YES >> GO TO 3.
NO >> Repair or replace damaged parts.
3.CHECK ENGINE SPEED SIGNAL (1)
1. Connect ECM harness connectors.
2. Check signal between ECM harness connector and ground with oscilloscope.
ECM Power steering control unit
Continuity
Connector Terminal Connector Terminal
E16 94 M61 10 Existed
Power steering control unit
— Continuity
Connector Terminal
M61 10 Ground Not existed

STC-10
< COMPONENT DIAGNOSIS >
ENGINE SPEED SIGNAL CIRCUIT
Is the inspection result normal?
YES >> GO TO 4.
NO >> Replace ECM. Refer to EC-14, "
ADDITIONAL SERVICE WHEN REPLACING CONTROL UNIT :
Description".
4.CHECK ENGINE SPEED SIGNAL (2)
1. Connect power steering control unit harness connector.
2. Check signal between power steering control unit harness connector and ground with oscilloscope.
Is the inspection result normal?
YES >> GO TO 5.
NO >> Replace power steering control unit. Refer to STC-19, "
Exploded View".
5.CHECK TERMINALS AND HARNESS CONNECTORS
 Check power steering control unit pin terminals for damage or loose connection with harness connector.
 Check ECM pin terminals for damage or loose connection with harness connector.
Is the inspection result normal?
YES >> INSPECTION END
NO >> Repair or replace damaged parts.
ECM
— Condition Voltage (Approx.)
Connector Terminal
E16 94 GroundEngine is running
 Warm-up condition
 Idle speed
Engine is running
 Warm-up condition
 Engine speed: Approx. 2,000 rpm
JSGIA0143ZZ
PBIA3655J
Power steering control unit
— Condition Voltage (Approx.)
Connector Terminal
M61 10 GroundEngine is running
 Warm-up condition
 Idle speed
Engine is running
 Warm-up condition
 Engine speed: Approx. 2,000 rpm
JSGIA0143ZZ
PBIA3655J

VEHICLE SPEED SIGNAL CIRCUIT
STC-11
< COMPONENT DIAGNOSIS >
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VEHICLE SPEED SIGNAL CIRCUIT
DescriptionINFOID:0000000003893533
Combination meter sends vehicle speed signal to power steering control unit.
Diagnosis ProcedureINFOID:0000000003893534
1.PERFORM COMBINATION METER SELF-DIAGNOSIS
With CONSULT-III
1. Turn the ignition switch ON.
2. Perform combination meter self-diagnosis. Refer to MWI-33, "
CONSULT-III Function (METER/M&A)".
Is any DTC detected?
YES >> Check the DTC.
NO >> GO TO 2.
2.CHECK HARNESS BETWEEN COMBINATION METER AND POWER STEERING CONTROL UNIT
1. Turn the ignition switch OFF.
2. Disconnect combination meter harness connector.
3. Disconnect power steering control unit harness connector.
4. Check continuity between combination meter harness connector and power steering control unit harness
connector.
5. Check continuity between power steering control unit harness connector and ground.
Is the inspection result normal?
YES >> GO TO 3.
NO >> Repair or replace damaged parts.
3.CHECK VEHICLE SPEED SIGNAL (1)
1. Connect combination meter harness connector.
2. Check combination meter input/output standard values. Refer to MWI-53, "
Reference Value".
Is the inspection result normal?
YES >> GO TO 4.
NO >> Replace combination meter Refer to MWI-126, "
Exploded View".
4.CHECK VEHICLE SPEED SIGNAL (2)
1. Connect power steering control unit harness connector.
2. Check signal between power steering control unit harness connector and ground with oscilloscope.
Combination meter Power steering control unit
Continuity
Connector Terminal Connector Terminal
M3430M618Existed
Power steering control unit
—Continuity
Connector Terminal
M61 8 Ground Not existed

STC-12
< COMPONENT DIAGNOSIS >
VEHICLE SPEED SIGNAL CIRCUIT
Is the inspection result normal?
YES >> GO TO 5.
NO >> Replace power steering control unit. Refer to STC-19, "
Exploded View".
5.CHECK TERMINALS AND HARNESS CONNECTORS
 Check power steering control unit pin terminals for damage or loose connection with harness connector.
 Check combination meter pin terminals for damage or loose connection with harness connector.
Is the inspection result normal?
YES >> INSPECTION END
NO >> Repair or replace damaged parts.
Power steering control unit
— Condition Voltage (Approx.)
Connector Terminal
M61 8 GroundVehicle speed: 40 km/h (25 MPH)
CAUTION:
Check air pressure of tire under
standard condition.
JSNIA0015GB

POWER STEERING CONTROL UNIT
STC-13
< ECU DIAGNOSIS >
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ECU DIAGNOSIS
POWER STEERING CONTROL UNIT
Reference ValueINFOID:0000000003893535
TERMINAL LAYOUT
PHYSICAL VALUES
JSGIA0023ZZ
Te r m i n a l N o .
(Wire color)Description
Condition Value (Approx.)
+ - Signal nameInput/
Output
1
(R/Y)GroundPower steering solenoid
valve voltageOutputVehicle speed: 0 km/h (0 MPH)
(Engine is running)4.4 – 6.6 V
Vehicle speed: 100 km/h (62 MPH) 2.4 – 3.6 V
3
(G/W)GroundIgnition switch power
supplyInputIgnition switch: ON Battery voltage
Ignition switch: OFF 0 V
5
(LG)GroundPower steering solenoid
valve ground—Always 0 V
6
(B)Ground Ground — Always 0 V
8
(L/B)Ground Vehicle speed signal InputVehicle speed: 40 km/h (25 MPH)
CAUTION:
Check air pressure of tire under
standard condition.
10
(V/W)Ground Engine speed signal InputEngine is running
 Warm-up condition
 Idle speed
Engine is running
 Warm-up condition
 Engine speed: Approx. 2,000 rpm
JSNIA0015GB
JSGIA0143ZZ
PBIA3655J

STC-14
< ECU DIAGNOSIS >
POWER STEERING CONTROL UNIT
CAUTION:
When using circuit tester or oscilloscope to measure voltage for inspection, be sure not to forcibly extend any connector ter-
minals.
Wiring Diagram - ELECTRONICALLY CONTROLLED POWER STEERING SYSTEM -
INFOID:0000000003893536
JCGWM0089GB

POWER STEERING CONTROL UNIT
STC-15
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Fail-SafeINFOID:0000000003893835
EPS system
JCGWM0090GB

STC-16
< ECU DIAGNOSIS >
POWER STEERING CONTROL UNIT
 EPS system enters the fail-safe mode (that allows the steering
force to be controlled without impairing the drivability) if any of the
input/output values to/from EPS system (power steering control
unit) deviate from the standard range.
NOTE:
The system enters the fail-safe mode if the engine speed remains
at 1,500 rpm or more for over 10 seconds while the vehicle is
stopped. This is normal.
 The fail-safe function is canceled when a vehicle speed signal of 2
km/h (1.2 MPH) or more is inputted or the ignition switch is turned
OFF→ON. EPS system restores the normal operation at that time.
JSGIA0426GB
ModeWarn-
ing lampDTC Detection point (malfunction part) Error area and root cause
Fail-safe
function— — Vehicle speed signal input Engine speed is 1,500 rpm or more and there is no vehicle
speed signal input for over 10 seconds during vehicle travel.
 Vehicle speed signal has abruptly dropped from 30 km/h (19
MPH) or more to 2 km/h (1.2 MPH) or less within 1.4 sec-
onds.

UNBALANCE STEERING WHEEL TURNING FORCE (TORQUE VARIATION)
STC-17
< SYMPTOM DIAGNOSIS >
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SYMPTOM DIAGNOSIS
UNBALANCE STEERING WHEEL TURNING FORCE (TORQUE VARIA-
TION)
DescriptionINFOID:0000000003893538
 Hard steering when fully turning the steering wheel.
 Light steering when driving at a high speed.
Diagnosis ProcedureINFOID:0000000003893539
1.CHECK SYSTEM FOR POWER SUPPLY AND GROUND
Perform trouble diagnosis for power supply and ground. Refer to STC-6, "
Diagnosis Procedure".
Is the inspection result normal?
YES >> GO TO 2.
NO >> Repair or replace damaged parts.
2.CHECK SYSTEM FOR VEHICLE SPEED SIGNAL
Perform trouble diagnosis for vehicle speed signal. Refer to STC-11, "
Diagnosis Procedure".
Is the inspection result normal?
YES >> GO TO 3.
NO >> Repair or replace damaged parts.
3.CHECK SYSTEM FOR ENGINE SPEED SIGNAL
Perform trouble diagnosis for engine speed signal. Refer to STC-9, "
Diagnosis Procedure".
Is the inspection result normal?
YES >> GO TO 4.
NO >> Repair or replace damaged parts.
4.CHECK SYSTEM FOR POWER STEERING SOLENOID VALVE
Perform trouble diagnosis for power steering solenoid valve. Refer to STC-7, "
Diagnosis Procedure".
Is the inspection result normal?
YES >> Perform the symptom diagnosis for the steering system. Refer to ST-2, "NVH Troubleshooting
Chart".
NO >> Repair or replace damaged parts.