NISSAN LATIO 2010 Service Repair Manual

C1607, C1608 EPS CONTROL UNIT
STC-15
< DTC/CIRCUIT DIAGNOSIS > [EPS]
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C1607, C1608 EPS CONTROL UNIT
DescriptionINFOID:0000000005600174
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:0000000005600175
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:0000000005600176
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-9, "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: January 20102010 Versa

STC-16
< DTC/CIRCUIT DIAGNOSIS >[EPS]
C1609 VEHICLE SPEED SIGNAL
C1609 VEHICLE SPEED SIGNAL
DescriptionINFOID:0000000005600177
EPS control unit receives the vehicle speed signal from ABS actuator and electric unit (control unit) via CAN
communication line.
DTC LogicINFOID:0000000005600178
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
“C1609” detected?
YES >> Proceed to diagnosis procedure. Refer to STC-16, "Diagnosis Procedure".
NO >> Inspection End.
Diagnosis ProcedureINFOID:0000000005600179
1.PERFORM ABS ACTUATOR AND ELECTRIC UNIT (CONTROL UNIT) SELF-DIAGNOSIS
With CONSULT-III
1. Turn the ignition switch OFF to ON.
2. Perform ABS actuator and electrical uni t (control unit) self-diagnosis. Refer to BRC-20, "
CONSULT-III
Function (ABS)".
Is any DTC detected?
YES >> Check the DTC. Refer to BRC-20, "CONSULT-III Function (ABS)".
NO >> GO TO 2.
2.PERFORM SELF-DIAGNOSIS
With CONSULT-III
Perform EPS control unit self-diagnosis.
Is DTC
“C1609” detected?
YES >> Replace EPS control unit. Refer to PS-9, "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
C1609 CAN VHCL SPEED • Malfunction is detected in vehicle speed signal that
is output from ABS actuator and electric unit (con-
trol unit) via CAN communication.
• ABS actuator and electric unit (control unit) input signal error is detected. • Harness or connector
• CAN communication line
• EPS control unit
• ABS malfunction
- Vehicle speed signal error
Revision: January 20102010 Versa

C1610 ENGINE STATUS SIGNALSTC-17
< DTC/CIRCUIT DIAGNOSIS > [EPS]
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C1610 ENGINE STATUS SIGNAL
DescriptionINFOID:0000000005600180
EPS control unit receives the engine status signal from ECM via CAN communication line.
DTC LogicINFOID:0000000005600181
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
“C1610” detected?
YES >> Proceed to diagnosis procedure. Refer to STC-17, "Diagnosis Procedure".
NO >> Inspection End.
Diagnosis ProcedureINFOID:0000000005600182
1.PERFORM ECM SELF-DIAGNOSIS
With CONSULT-III
1. Turn the ignition switch OFF to ON.
2. Perform ECM self-diagnosis. Refer to EC-98, "
CONSULT-III Function" (HR16DE), EC-612, "CONSULT-III
Function (ENGINE)" (MR18DE).
Is any DTC detected?
YES >> Check the DTC. Refer to EC-468, "DTCIndex" (HR16DE), EC-503, "U0101-U1001" (MR18DE).
NO >> GO TO 2.
2.PERFORM SELF-DIAGNOSIS
With CONSULT-III
Perform EPS control unit self-diagnosis.
Is DTC
“C1610” detected?
YES >> Replace EPS control unit. Refer to PS-9, "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
C1610 CAN ENG RPM • Malfunction is detected in engine status signal
that is output from ECM via CAN communica-
tion.
• ECM input signal error is detected. • Harness or connector
• CAN communication line
• EPS control unit
•ECM
- Engine status signal error
Revision: January 20102010 Versa

STC-18
< DTC/CIRCUIT DIAGNOSIS >[EPS]
U1000 CAN COMM CIRCUIT
U1000 CAN COMM CIRCUIT
DescriptionINFOID:0000000005600183
CAN (Controller Area Network) is a serial communication line for real time application. It is an on-vehicle mul-
tiplex communication line with high data communication s
peed and excellent error detection ability. Many elec-
tronic control units are equipped onto a vehicle, and each control unit shares information and links with other
control units during operation (not independent). In CA N communication, control units are connected with 2
communication lines (CAN-H line, CAN-L line) allowing a high rate of information transmission with less wiring.
Each control unit communicate data but selectively reads required data only.
DTC LogicINFOID:0000000005600184
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
“U1000” detected?
YES >> Proceed to diagnosis procedure. Refer to STC-18, "Diagnosis Procedure".
NO >> Inspection End
Diagnosis ProcedureINFOID:0000000005600185
1.PERFORM SELF-DIAGNOSIS
With CONSULT-III
Perform EPS control unit self-diagnosis.
Is DTC
“U1000” detected?
YES >> CAN specification chart. Refer to LAN-17, "Trouble Diagnosis Flow Chart".
NO >> Inspection End.
DTC Display item Malfunction detected condition Possible cause
U1000 CAN COMM CIRCUIT EPS control unit is not transmitting/re-
ceiving CAN communication signal for 2
seconds or more.• CAN communication error
• EPS control unit
Revision: January 20102010 Versa

EPS WARNING LAMPSTC-19
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EPS WARNING LAMP
DescriptionINFOID:0000000005600187
• 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:0000000005600188
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:0000000005600189
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-9, "
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: January 20102010 Versa

STC-20
< ECU DIAGNOSIS INFORMATION >[EPS]
EPS CONTROL UNIT
ECU DIAGNOSIS INFORMATION
EPS CONTROL UNIT
Reference ValueINFOID:0000000005600190
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: January 20102010 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: January 20102010 Versa

STC-22
< ECU DIAGNOSIS INFORMATION >[EPS]
EPS CONTROL UNIT
Wiring Diagram - ELECTRONICALLY CONTROLLED POWER STEERING SYSTEM -
INFOID:0000000005600191
BGWA0001E
Revision: January 20102010 Versa

EPS CONTROL UNITSTC-23
< ECU DIAGNOSIS INFORMATION > [EPS]
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Fail-SafeINFOID:0000000005600192
• 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: January 20102010 Versa

STC-24
< ECU DIAGNOSIS INFORMATION >[EPS]
EPS CONTROL UNIT
DTC Inspection Priority Chart
INFOID:0000000005600193
When multiple DTCs are detected simultaneously, c heck one by one depending on the following priority list.
DTC IndexINFOID:0000000005600194
Priority Priority order item (DTC)
1 U1000 CAN COMM CIRCUIT
2 C1601 BATTERY POWER SUPPLY
3 Other than the above
DTC Items (CONSULT-III screen terms) Reference
C1601 BATTERY VOLT STC-9, "
DTC Logic"
C1604TORQUE SENSOR STC-11, "DTC Logic"
C1606EPS MOTOR STC-13, "DTC Logic"
C1607EEPROM STC-15, "DTC Logic"
C1608CONTROL UNIT STC-15, "DTC Logic"
C1609CAN VHCL SPEED STC-16, "DTC Logic"
C1610CAN ENG RPM STC-17, "DTC Logic"
U1000CAN COMM CIRCUIT STC-18, "DTC Logic"
Revision: January 20102010 Versa