2008 NISSAN TIIDA steering

STC-12
< SERVICE INFORMATION >[EPS]
TROUBLE DIAGNOSIS
CAUTION:
If “CAN COMM CIRCUIT [U1000]” is displayed with other DTCs, first perform the trouble diagnosis for CAN communication
line.
How to Erase Self-Diagnostic Results
1. Perform applicable inspection of malfunctioning item and then repair or replace.
2. Turn ignition switch “OFF” to erase memory.
3. Turn ignition switch “ON” and select “SELF-DIAG RESULTS” mode with CONSULT-III.
4. Touch “ERASE” on CONSULT-III screen to erase DTC memory.
CAUTION:
If memory cannot be erased, perform diagnosis.
DATA MONITOR
Display Item List
EPS CONTROL UNIT PART NUMBER
Display a part number of EPS control unit carried by a vehicle.
Item
(CONSULT-III screen terms)Diagnostic item is detected when.... Check item
BATTERY VOLT
[C1601]When the power supply malfunction supplied to EPS control unit is
detected.STC-14, "
DTC C1601
BATTERY VOLT"
TORQUE SENSOR
[C1604]When the torque sensor malfunction assembled in steering column
assembly is detected. STC-15, "DTC C1604
TORQUE SENSOR"
EPS MOTOR
[C1606]When the motor driver malfunction of EPS control unit or EPS motor
malfunction is detected.STC-16, "DTC C1606
EPS MOTOR"
EEPROM
[C1607]When the memory (EEPROM) system malfunction is detected in
EPS control unit.STC-17, "DTC C1607
EEPROM"
CONTROL UNIT
[C1608]When the internal malfunction is detected in EPS control unit.STC-17, "DTC C1608
CONTROL UNIT"
CAN VHCL SPEED
[C1609]When the malfunction is detected in vehicle speed signal received
with CAN communication.STC-18, "DTC C1609
CAN VHCL SPEED"
CAN ENG RPM
[C1610]When the malfunction is detected in engine status signal received
with CAN communication.STC-19, "DTC C1610
CAN ENG RPM"
CAN COMM CIRCUIT
[U1000]When EPS control unit is not transmitting or receiving CAN commu-
nication signal 2 seconds or more.STC-19, "DTC U1000
CAN COMM CIRCUIT"
NO DTC IS DETECTED.
FURTHER TESTING MAY BE RE-
QUIRED.No NG item has been detected. —
Monitor item (Unit) Remarks
MOTOR VOL (V) Power supply voltage for EPS control unit is displayed
TORQUE SENSOR (Nm) Steering wheel turning force detected by torque sensor is displayed
MOTOR SIG (A) Current commanded value to EPS motor is displayed
MOTOR CURRENT (A) Current value consumed by EPS motor is displayed
VEHICLE SPEED (km/h) or (mph) Vehicle speed is displayed from vehicle speed signal with CAN communication
WARNING LAMP (ON/OFF) EPS warning lamp control status is displayed
DERATING STAT (ON/OFF) Protect overload status is displayed
ENGINE STATUS (STOP/RUN) Engine speed is displayed from engine status signal with CAN communication

TROUBLE DIAGNOSIS
STC-13
< SERVICE INFORMATION >[EPS]
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Symptom ChartINFOID:0000000001703882
If EPS warning lamp turns ON, perform self-diagnosis. Refer to STC-11, "CONSULT-III Function (EPS)" .
Symptom Condition Check item Reference page
EPS warning lamp does not turn ON when ig-
nition switch to “ON”.
(EPS warning lamp check)Ignition switch: ONCAN communication line
STC-21
Combination meter
EPS warning lamp does not turn OFF for sev-
eral seconds after starting the engineEngine runningCAN communication line
STC-21
Power supply and ground for
EPS control unit
Torque sensor
EPS motor
Vehicle speed signal
Engine status signal
Combination meter
Steering wheel turning force is heavy or light,
while driving• While driving
• Steering wheel turningCAN communication line
STC-22
Vehicle speed signal
Engine status signal
EPS motor
Steering wheel turning force
(Mechanical malfunction)
Unbalance steering wheel turning force and
return between right and left, while driving• While driving
• Steering wheel turningWheel alignment
STC-23
Steering wheel turning force
(Mechanical malfunction)
Unbalance steering wheel turning force,
while driving (Torque variation)• While driving
• Steering wheel turningSteering column intermediate
shaft installation condition
STC-24
Steering wheel turning force
(Mechanical malfunction)

TROUBLE DIAGNOSIS FOR SYSTEM
STC-15
< SERVICE INFORMATION >[EPS]
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3. Check continuity between EPS control unit harness connector
(A) terminal and ground.
Also check harness for short to power.
4. Connect EPS control unit harness connector.
OK or NG
OK >> GO TO 3.
NG >> Repair open circuit or short to ground or short to power
in harness or connectors.
3.CHECK DTC
Start engine.
Does EPS warning lamp turn OFF?
YES >>INSPECTION END
NO >> Perform self-diagnosis, repair or replace damaged parts. Refer to STC-11, "
CONSULT-III Func-
tion (EPS)".
DTC C1604 TORQUE SENSORINFOID:0000000001703884
CONSULT-III REFERENCE VALUE IN DATA MONITOR MODE
Data are reference value.
*: In the front of the value, “L” is displayed at steering left and “R” is displayed at steering right.
TERMINALS AND REFERENCE VALUES FOR EPS CONTROL UNIT
Refer to STC-10, "EPS Terminal and Reference Value".
DIAGNOSTIC PROCEDURE
1.CHECK TORQUE SENSOR SIGNAL
With CONSULT-III
1. Start engine.
2. Select “DATA MONITOR” mode for “EPS” with CONSULT-III.
3. Check the value of “TORQUE SENSOR”. Refer to STC-9, "
EPS Control Unit Input/Output Signal Refer-
ence Value".
Without CONSULT-III1. Start engine.
2. Check voltage between EPS control unit harness connector M53 terminals 4, 5, 6, 7 and ground. Refer to
STC-10, "
EPS Terminal and Reference Value".
OK or NG
OK >> GO TO 3.
NG >> GO TO 2.
2.CHECK HARNESS AND CONNECTOR
1. Turn ignition switch “OFF”.
2. Disconnect EPS control unit harness connector and torque sensor harness connector.
Connector Terminal Continuity
M54 18 Yes
SGIA1628E
Monitor item (Unit) Content Condition Display value
TORQUE SENSOR (Nm) Steering wheel turning force Engine runningSteering wheel: Not steering
(There is no steering force)0.00 Nm
Steering wheel: Steering0 – 8.19 Nm*
(The value is changed
according to steering
left or right)

STC-16
< SERVICE INFORMATION >[EPS]
TROUBLE DIAGNOSIS FOR SYSTEM
3. Check continuity between EPS control unit harness connector
(A) M53 terminals 4, 5, 6, 7 and torque sensor harness connec-
tor (B) M63 terminals 1, 2, 3, 4.
Also check harness for short to ground and short to power.
4. Connect EPS control unit harness connector and torque sensor harness connector.
OK or NG
OK >> GO TO 3.
NG >> Repair or replace damaged parts.
3.CHECK EPS CONTROL UNIT
Check EPS control unit input/output signal. Refer to STC-9, "
EPS Control Unit Input/Output Signal Reference
Va l u e".
OK or NG
OK >> GO TO 4.
NG >> Check EPS control unit pin terminals for damage or loose connection with harness connector. If
any items are damaged, repair or replace damaged parts.
4.CHECK DTC
Perform the self-diagnosis, after driving the vehicle for a while.
OK or NG
OK >>INSPECTION END
NG >> Torque sensor is malfunctioning. Replace steering column assembly. Refer to PS-9, "
Removal
and Installation".
DTC C1606 EPS MOTORINFOID:0000000001703885
CONSULT-III REFERENCE VALUE IN DATA MONITOR MODE
Data are reference value.
* : Almost in accordance with the value of “MOTOR SIG”. It is not a malfunction though these values are not accorded when steering
quickly.
TERMINALS AND REFERENCE VALUES FOR EPS CONTROL UNIT
Refer to STC-10, "EPS Terminal and Reference Value".
DIAGNOSTIC PROCEDURE
1.CHECK EPS MOTOR SIGNAL
Terminal Continuity
4 – 3
Ye s 5 – 2
6 – 1
7 – 4
SGIA1629E
Monitor item (Unit) Content Condition Display value
MOTOR SIG (A)Command current to EPS
motorEngine runningSteering wheel: Not steering
(There is no steering force)0.00 A
Steering wheel: Steering0 – 65.00 A
(The value is changed
according to steering left
or right)
MOTOR CURRENT (A)Consumption current of
EPS motorEngine runningSteering wheel: Not steering
(There is no steering force)0.00 A
Steering wheel: Steering0 – 65.00 A*
(The value is changed
according to steering left
or right)

TROUBLE DIAGNOSIS FOR SYSTEM
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< SERVICE INFORMATION >[EPS]
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With CONSULT-III
1. Start engine.
2. Select “DATA MONITOR” mode for “EPS” with CONSULT-III.
3. Check the values of “MOTOR SIG” and “MOTOR CURRENT”. Refer to STC-9, "
EPS Control Unit Input/
Output Signal Reference Value".
OK or NG
OK >> GO TO 3.
NG >> GO TO 2.
2.CHECK EPS MOTOR
1. Turn ignition switch “OFF”.
2. Disconnect EPS control unit harness connector.
3. Check resistance between EPS control unit harness connector
(A) terminals.
4. Connect EPS control unit harness connector.
OK or NG
OK >> GO TO 3.
NG >> EPS motor is malfunctioning. Replace steering column
assembly. Refer to PS-9, "
Removal and Installation".
3.CHECK EPS CONTROL UNIT
Check EPS control unit input/output signal. Refer to STC-9, "
EPS Control Unit Input/Output Signal Reference
Va l u e".
OK or NG
OK >> GO TO 4.
NG >> Check EPS control unit pin terminals for damage or loose connection with harness connector. If
any items are damaged, repair or replace damaged parts.
4.CHECK DTC
Perform the self-diagnosis, after driving the vehicle for a while.
OK or NG
OK >>INSPECTION END
NG >> GO TO 3.
DTC C1607 EEPROMINFOID:0000000001703886
DIAGNOSTIC PROCEDURE
1.PERFORM SELF-DIAGNOSIS
With CONSULT-III
1. Turn ignition switch “ON”. (Do not start engine.)
2. Select “SELF-DIAG RESULTS” mode for “EPS” with CONSULT-III.
3. Touch “ERASE”.
4. Turn ignition switch “OFF”, and wait at least 10 seconds.
5. Start engine.
6. Perform the self-diagnosis again.
Is the
“EEPROM [C1607]” displayed?
YES >> Replace EPS control unit. Refer to PS-9, "Removal and Installation".
NO >>INSPECTION END
DTC C1608 CONTROL UNITINFOID:0000000001703887
DIAGNOSTIC PROCEDURE
Connector Terminal Resistance
M60 19 – 20 Approx. 0.1 Ω or less
SGIA1630E

STC-20
< SERVICE INFORMATION >[EPS]
TROUBLE DIAGNOSIS FOR SYSTEM
3. Check resistance between EPS control unit harness connector
(A) terminals.
4. If NG, replace the steering column assembly. Refer to PS-9,
"Removal and Installation".
Connector Terminal Resistance
M60 19 – 20 Approx. 0.1 Ω or less
SGIA1630E

STC-22
< SERVICE INFORMATION >[EPS]
TROUBLE DIAGNOSIS FOR SYMPTOMS
5. Turn ignition switch “OFF”.
6. Check voltage between EPS control unit harness connector (A)
terminals and ground.
7. Connect EPS control unit harness connector.
OK or NG
OK >> GO TO 3.
NG >> Check the following. If any items are damaged, repair or replace damaged parts.
• 60 A fusible link (No. m, located in the fuse and fusible link block). Refer to PG-3
.
• 10 A fuse [No. 2, located in the fuse block (J/B)]. Refer to PG-3
.
• Harness for short or open between battery and EPS control unit harness connector M54 termi-
nal 17.
• Harness for short or open between ignition switch and EPS control unit harness connector M53
terminal 10.
3.CHECK EPS CONTROL UNIT GROUND CIRCUIT
1. Turn ignition switch “OFF”.
2. Disconnect EPS control unit harness connector.
3. Check continuity between EPS control unit harness connector
(A) terminal and ground.
Also check harness for short to power.
4. Connect EPS control unit harness connector.
OK or NG
OK >> GO TO 4.
NG >> Repair open circuit or short to ground or short to power
in harness or connectors.
4.CHECK EPS CONTROL UNIT
Check EPS control unit input/output signal. Refer to STC-9, "
EPS Control Unit Input/Output Signal Reference
Va l u e" .
OK or NG
OK >> GO TO 5.
NG >> Check EPS control unit pin terminals for damage or loose connection with harness connector. If
any items are damaged, repair or replace damaged parts.
5.SYMPTOM CHECK
Check again.
OK or NG
OK >>INSPECTION END
NG >> Replace combination meter. Refer to DI-20, "
Removal and Installation" .
Steering Wheel Turning Force Is Heavy or LightINFOID:0000000001703894
SYMPTOM:
Steering wheel turning force is heavy or light, while driving.
DIAGNOSTIC PROCEDURE
1.CHECK SYSTEM FOR CAN COMMUNICATION LINE
Perform self-diagnosis. Refer to STC-11, "
CONSULT-III Function (EPS)" .
Connector Terminal Voltage
M53 10 – Ground Approx. 0 V
M54 17 – Ground Battery voltage
SGIA1627E
Connector Terminal Continuity
M54 18 YES
SGIA1628E

TROUBLE DIAGNOSIS FOR SYMPTOMS
STC-23
< SERVICE INFORMATION >[EPS]
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Is the “CAN COMM CIRCUIT [U1000]” displayed?
YES >> Perform trouble diagnosis for CAN communication line. Refer to STC-19, "DTC U1000 CAN
COMM CIRCUIT" .
NO-1 >> With ABS: GO TO 2.
NO-2 >> Without ABS: GO TO 3.
2.CHECK VEHICLE SPEED SIGNAL FROM ABS ACTUATOR AND ELECTRIC UNIT (CONTROL UNIT)
Perform self-diagnosis with ABS actuator and electric unit (control unit). Refer to BRC-18, "
CONSULT-III
Function (ABS)" .
Is any malfunction detected by self-diagnosis?
YES >> Check the malfunctioning system.
NO >> GO TO 4.
3.CHECK VEHICLE SPEED SIGNAL FROM TRANSMISSON CONTROL MODULE (TCM)
Perform self-diagnosis with TCM. Refer to AT-73, "
CONSULT-III Function (A/T)" .
Is any malfunction detected by self-diagnosis?
YES >> Check the malfunctioning system.
NO >> GO TO 4.
4.CHECK COMBINATION METER SIGNAL
Perform self-diagnosis with combination meter. Refer to DI-13, "
CONSULT-III Function (METER/M&A)" .
Is any malfunction detected by self-diagnosis?
YES >> Check the malfunctioning system.
NO >> GO TO 5.
5.CHECK ENGINE STATUS SIGNAL
Perform self-diagnosis for ECM. Refer to EC-109, "
CONSULT-II Function (ENGINE)" .
Is any malfunction detected by self-diagnosis?
YES >> Check the malfunctioning system.
NO >> GO TO 6.
6.CHECK EPS MOTOR SYSTEM
Perform trouble diagnosis for EPS motor. Refer to STC-16, "
DTC C1606 EPS MOTOR" .
OK or NG
OK >> GO TO 7.
NG >> Repair or replace damaged parts.
7.CHECK EPS CONTROL UNIT
Check EPS control unit input/output signal. Refer to STC-9, "
EPS Control Unit Input/Output Signal Reference
Va l u e" .
OK or NG
OK >> GO TO 8.
NG >> Check EPS control unit pin terminals for damage or loose connection with harness connector. If
any items are damaged, repair or replace damaged parts.
8.SYMPTOM CHECK
Check again.
OK or NG
OK >>INSPECTION END
NG >> Check the steering wheel turning force because there may be mechanical malfunction. Refer to
PS-6, "
On-Vehicle Inspection and Service" .
Unbalance Steering Wheel Turning Force and Return Between Right and Left
INFOID:0000000001703895
SYMPTOM:
Unbalance steering wheel turning force and return between right and left, while driving.