2011 NISSAN TIIDA steering

C1607, C1608 EPS CONTROL UNIT
STC-15
< DTC/CIRCUIT DIAGNOSIS > [EPS]
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C1607, C1608 EPS CONTROL UNIT
DescriptionINFOID:0000000005931239
EPS control unit performs an arithmetical operation on data, such as steering wheel turning force (sensor sig-
nal) from the torque sensor, vehicle speed signal, etc. T hen it generates an optimum assist torque signal to the
EPS motor according to the driving condition.
DTC LogicINFOID:0000000005931240
DTC DETECTION LOGIC
DTC CONFIRMATION PROCEDURE
1.DTC REPRODUCTION PROCEDURE
With CONSULT-III
1. Turn the ignition switch OFF to ON.
2. Perform EPS control unit self-diagnosis.
Is DTC
“C1607” or “C1608” detected?
YES >> Proceed to diagnosis procedure. Refer to STC-15, "Diagnosis Procedure".
NO >> Inspection End.
Diagnosis ProcedureINFOID:0000000005931241
1.PERFORM SELF-DIAGNOSIS
With CONSULT-III
1. Turn the ignition switch OFF to ON.
2. Erase EPS control unit self-diagnostic results.
3. Perform EPS control unit self-diagnosis.
Is DTC
“C1607” or “C1608” detected?
YES >> Replace EPS control unit. Refer to PS-10, "Removal and Installation".
NO >> Check EPS control unit pin terminals for damage or loose connection with harness connector. If
any item are damaged, repair or replace error-detected parts.
DTC Display item Malfunction detected condition Possible cause
C1607 EEPROM When the memory (EEPROM)
system malfunction is
detected in EPS control unit.
EPS control unit
C1608 CONTROL UNIT When the internal malfunction is detected in EPS
control unit.
Revision: May 2010
2011 Versa

EPS WARNING LAMPSTC-19
< DTC/CIRCUIT DIAGNOSIS > [EPS]
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EPS WARNING LAMP
DescriptionINFOID:0000000005931251
• Turn ON when there is a malfunction in EPS system. If indicates that fail-safe mode is engaged and enters a
manual steering state (Control turning force steering wheel becomes heavy).
• Also turns ON when ignition switch is turned ON, for purpose of lamp check. Turns OFF after the engine
starts, if system is normal.
EPS WARNING LAMP INDICATION
CAUTION:
EPS warning lamp also turns ON due to data reception error, CAN communication error etc.
Component Function CheckINFOID:0000000005931252
1.CHECK THE ILLUMINATION OF THE EPS WARNING LAMP
Check that the EPS warning lamp turns ON when igni tion switch turns ON. Then, EPS warning lamp turns
OFF after the engine is started.
Is the inspection result normal?
YES >> Inspection End
NO >> Perform trouble diagnosis. Refer to STC-19, "
Diagnosis Procedure".
Diagnosis ProcedureINFOID:0000000005931253
1.PERFORM SELF-DIAGNOSIS
With CONSULT-III
1. Turn the ignition switch OFF to ON.
2. Perform EPS control unit self-diagnosis.
Is any DTC detected?
YES >> Check the DTC. Refer to STC-24, "DTC Index".
NO >> GO TO 2.
2.CHECK EPS WARNING LAMP SIGNAL
With CONSULT-III
1. Turn the ignition switch ON. CAUTION:
Never start the engine.
2. On “DATA MONITOR”, select “WARNING LAMP”.
3. Check that the EPS warning lamp is turned ON.
4. Start the engine. CAUTION:
Stop the vehicle.
5. Check that the EPS warning lamp is turned OFF.
Is the inspection result normal?
YES >> Perform the trouble diagnosis for combinat ion meter power supply circuit. Refer to DI-15, "Power
Supply and Ground Circuit Inspection".
NO >> Replace the EPS control unit. Refer to PS-10, "
Removal and Installation".
Condition EPS warning lamp
Ignition switch ON. (Lamp check) ON
Engine running. OFF
EPS system malfunction [Oth er diagnostic item] OFF
Revision: May 2010 2011 Versa

STC-20
< ECU DIAGNOSIS INFORMATION >[EPS]
EPS CONTROL UNIT
ECU DIAGNOSIS INFORMATION
EPS CONTROL UNIT
Reference ValueINFOID:0000000005931254
VALUES ON THE DIAGNOSIS TOOL
CAUTION:
The output signal indicates the EPS control unit calculation data. Th
e normal values will be displayed
even in the event that the output circuit (harness) is open.
*1: Almost in accordance with the value of MOTOR SIG. It is not a malfunction though these values are not accorded when steerin g
quickly.
*2: It is not a malfunction, though it might not be corresponding just after ignition switch in turned ON.
TERMINAL LAYOUT
PHYSICAL VALUES
Monitor item Display content Data monitor
Condition Display value
MOTOR VOL Power supply voltage for
EPS control unit Ignition switch: ON
Battery voltage
TORQUE SENSOR Steering wheel turning
force Engine runningSteering wheel: Not steering
(There is no steering force)
Approx. 0 Nm
Steering wheel: Right turn Positive value (Nm)
Steering wheel: Left turn Negative value (Nm)
MOTOR CURRENT Consumption current of
EPS motor Engine runningSteering wheel: Not steering
(There is no steering force)
Approx. 0 A
Steering wheel: Right or left
turn Displays consumption cur-
rent of EPS motor (A)
*1
MOTOR SIG
Command current to
EPS motor Engine runningSteering wheel: Not steering
(There is no steering force)
Approx. 0 A
Steering wheel: Right turn Negative value (A)
Steering wheel: Left turn Positive value (A)
DERATING STAT Displays overload sta-
tus.
Engine running
Off
VEHICLE SPEED Vehicle speed Vehicle stopped
0 km/h (0 mph)
While driving Approximately equal to the
indication on speedometer
(inside of
±10%)
*2
WARNING LAMP EPS warning lamp con-
dition EPS warning lamp: ON
On
EPS warning lamp: OFF Off
ENGINE STATUS Engine status Engine not running
Stop
Engine running Run
SGIA1624E
Revision: May 2010 2011 Versa

EPS CONTROL UNITSTC-21
< ECU DIAGNOSIS INFORMATION > [EPS]
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Te r m i n a l N o . (Wire Color) Description
ConditionVa l u e
(Approx.)
+ − Signal name Input/Output
4
(V) Ground Torque sensor sub Input Ignition switch: ON
Steering wheel: Not
steering (There is no
steering force) 2.5 V
Engine running Steering wheel: steer-
ing 1.6 V – 3.4 V
(The value is changed according to steering
left or right)
5
(BR −) Ground
Torque sensor power
supply Output
Ignition switch: ON 5 V
6
(− ) Ground Torque sensor main Input Ignition switch: ON
Steering wheel: Not
steering (There is no
steering force) 2.5 V
Engine running Steering wheel: steer-
ing 1.6 V – 3.4 V
(The value is changed according to steering
left or right)
7
(R) Ground Torque sensor ground —
Always0 V
9
(L) Ground CAN-H
Input/Output ——
10
(O) Ground Ignition power supply Input Ignition switch: ON
Battery voltage
Ignition switch: OFF 0 V
16
(P) Ground CAN-L
Input/Output ——
17
(R) Ground Battery power supply Input
AlwaysBattery voltage
18
(B) Ground Ground
—Always 0 V
19 — Motor —— —
20 — Motor —— —
Revision: May 2010
2011 Versa

STC-22
< ECU DIAGNOSIS INFORMATION >[EPS]
EPS CONTROL UNIT
Wiring Diagram - ELECTRONICALLY CONTROLLED POWER STEERING SYSTEM -
INFOID:0000000005931255
ABGWA0024GB
Revision: May 2010 2011 Versa

EPS CONTROL UNITSTC-23
< ECU DIAGNOSIS INFORMATION > [EPS]
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Fail-SafeINFOID:0000000005931256
• If any malfunction occurs in the system, and control unit detects the malfunction, EPS warning lamp on com- bination meter turns ON to indicate system malfunction.
• When EPS warning lamp is ON, enters into a manual steering state. (Control turning force steering wheel
becomes heavy.)
AAGWA0003GB
Revision: May 2010 2011 Versa

STEERING WHEEL TURNING FORCE IS HEAVY OR LIGHTSTC-27
< SYMPTOM DIAGNOSIS > [EPS]
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STEERING WHEEL TURNING FO RCE IS HEAVY OR LIGHT
DescriptionINFOID:0000000005931263
Steering wheel turning force is heavy or light.
Diagnosis ProcedureINFOID:0000000005931264
1.CHECK THE ILLUMINATION OF THE EPS WARNING LAMP
Check that the EPS warning lamp turns ON when igni tion switch turns ON. Then, EPS warning lamp turns
OFF after the engine is started.
Is the inspection result normal?
YES >> GO TO 4.
NO >> GO TO 2.
2.PERFORM SELF-DIAGNOSIS
With CONSULT-III
1. Turn the ignition switch OFF to ON.
2. Perform EPS control unit self-diagnosis.
Is any DTC detected?
YES >> Check the DTC. Refer to STC-24, "DTC Index".
NO >> GO TO 3.
3.CHECK EPS CONTROL UNIT SIGNAL
With CONSULT-III
1. Start the engine. CAUTION:
Stop the vehicle.
2. Turn steering wheel from full left stop to full right stop.
3. Select “TORQUE SENSOR” of “DATA MONITOR” for EPS control unit.
Is the inspection result normal?
YES >> GO TO 5.
NO >> GO TO 4.
4.CHECK EPS MOTOR
Perform the trouble diagnosis of EPS motor. Refer to STC-13, "
Diagnosis Procedure".
Is the inspection result normal?
YES >> GO TO 5.
NO >> Repair or replace the specific malfunctioning part.
5.CHECK STEERING WH EEL TURNING FORCE
Check the steering wheel turning force. Refer to PS-6, "
On-Vehicle Inspection and Service".
Is the inspection result normal?
YES >> Inspection End
NO >> Check the steering wheel turning force for mechanical malfunction. Refer to PS-6, "
On-Vehicle
Inspection and Service".
Monitor item ConditionDisplay value
TORQUE SENSOR Steering wheel: Not steer-
ing (There is no steering
force)
Approx. 0 Nm
Steering wheel: Right turn Positive value (Nm)
Steering wheel: Left turn Negative value (Nm)
Revision: May 2010 2011 Versa

STC-28
< SYMPTOM DIAGNOSIS >[EPS]
UNBALANCE STEERING WHEEL TURNING FORCE AND RETURN BETWEEN
RIGHT AND LEFT
UNBALANCE STEERING WHEEL TU RNING FORCE AND RETURN BE-
TWEEN RIGHT AND LEFT
DescriptionINFOID:0000000005931265
Unbalance steering wheel turning force and return between right and left.
Diagnosis ProcedureINFOID:0000000005931266
1.CHECK THE ILLUMINATION OF THE EPS WARNING LAMP
Check that the EPS warning lamp turns ON when igni tion switch turns ON. Then, EPS warning lamp turns
OFF after the engine is started.
Is the inspection result normal?
YES >> GO TO 2.
NO >> Refer to STC-26, "
Diagnosis Procedure".
2.CHECK WHEEL ALIGNMENT
1. Check the wheel alignment. Refer to FSU-7, "
On-Vehicle Inspection and Service".
2. Perform EPS control unit self-diagnosis.
Is the inspection result normal?
YES >> GO TO 3.
NO >> Adjustment of wheel alignment.
3.CHECK EPS CONTROL UNIT SIGNAL
With CONSULT-III
1. Start the engine. CAUTION:
Stop the vehicle.
2. Turn steering wheel from full left stop to full right stop.
3. Select “TORQUE SENSOR” of “DATA MONITOR” for EPS control unit.
Is the inspection result normal?
YES >> GO TO 5.
NO >> GO TO 4.
4.CHECK EPS MOTOR
Perform the trouble diagnosis of EPS motor. Refer to STC-13, "
Diagnosis Procedure".
Is the inspection result normal?
YES >> GO TO 5.
NO >> Repair or replace the specific malfunctioning part.
5.CHECK STEERING WHEEL TURNING FORCE
Check the steering wheel turning force. Refer to PS-6, "
On-Vehicle Inspection and Service".
Is the inspection result normal?
YES >> Inspection End.
NO >> Check the steering wheel turning force for mechanical malfunction. Refer to PS-6, "
On-Vehicle
Inspection and Service".
Monitor item ConditionDisplay value
TORQUE SENSOR Steering wheel: Not steer-
ing (There is no steering
force)
Approx. 0 Nm
Steering wheel: Right turn Positive value (Nm)
Steering wheel: Left turn Negative value (Nm)
Revision: May 2010 2011 Versa