STC-1
STEERING CONTROL SYSTEM
G STEERING
CONTENTS
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SECTION STC
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STC
Revision: June 20062007 Versa
EPS
PRECAUTIONS .......................................................... 3
Precautions for Supplemental Restraint System
(SRS) “AIR BAG” and “SEAT BELT PRE-TEN-
SIONER” .................................................................. 3
Precautions Necessary for Steering Wheel Rotation
After Battery Disconnect .......................................... 3
OPERATION PROCEDURE ................................. 3
Service Notice or Precautions for EPS System ....... 4
EPS SYSTEM ............................................................. 5
System Description .................................................. 5
EPS CONTROL UNIT ........................................... 5
EPS MOTOR ......................................................... 5
TORQUE SENSOR ............................................... 5
REDUCTION GEAR .............................................. 5
EPS WARNING LAMP .......................................... 5
System Diagram ....................................................... 6
COMPONENTS FUNCTION DESCRIPTION ....... 6
CAN Communication ................................................ 6
SYSTEM DESCRIPTION ...................................... 6
TROUBLE DIAGNOSIS .............................................. 7
Fail-Safe Function .................................................... 7
How to Perform Trouble Diagnosis .......................... 7
BASIC CONCEPT ................................................. 7
PRECAUTIONS FOR TROUBLE DIAGNOSIS ..... 7
INTERVIEW .......................................................... 7
Component Parts Location ....................................... 8
Wiring Diagram — EPS — ....................................... 9
EPS Control Unit Input/Output Signal Reference
Values .....................................................................11
SPECIFICATIONS WITH CONSULT-II ................11
SPECIFICATIONS BETWEEN EPS CONTROL
UNIT TERMINALS .............................................. 12
CONSULT-II Function (EPS) .................................. 13
FUNCTION .......................................................... 13
CONSULT-II SETTING PROCEDURE ................ 13
SELF-DIAG RESULTS MODE ............................ 13
DATA MONITOR ................................................. 14
EPS CONTROL UNIT PART NUMBER .............. 14
Symptom Chart ...................................................... 15TROUBLE DIAGNOSIS FOR SYSTEM .................... 16
DTC C1601 BATTERY VOLT ................................. 16
CONSULT-II REFERENCE VALUE IN DATA
MONITOR MODE ................................................ 16
EPS CONTROL UNIT TERMINALS AND REF-
ERENCE VALUE ................................................. 16
DIAGNOSTIC PROCEDURE .............................. 17
DTC C1604 TORQUE SENSOR ............................ 19
CONSULT-II REFERENCE VALUE IN DATA
MONITOR MODE ................................................ 19
EPS CONTROL UNIT TERMINALS AND REF-
ERENCE VALUE ................................................. 19
DIAGNOSTIC PROCEDURE .............................. 19
DTC C1606 EPS MOTOR ...................................... 21
CONSULT-II REFERENCE VALUE IN DATA
MONITOR MODE ................................................ 21
EPS CONTROL UNIT TERMINALS AND REF-
ERENCE VALUE ................................................. 21
DIAGNOSTIC PROCEDURE .............................. 21
DTC C1607 EEPROM ............................................ 22
DIAGNOSTIC PROCEDURE .............................. 22
DTC C1608 CONTROL UNIT ................................. 22
DIAGNOSTIC PROCEDURE .............................. 22
DTC C1609 CAN VHCL SPEED ............................ 23
CONSULT-II REFERENCE VALUE IN DATA
MONITOR MODE ................................................ 23
DIAGNOSTIC PROCEDURE .............................. 23
DTC C1610 CAN ENG RPM .................................. 24
CONSULT-II REFERENCE VALUE IN DATA
MONITOR MODE ................................................ 24
DIAGNOSTIC PROCEDURE .............................. 24
DTC U1000 CAN COMM CIRCUIT ........................ 24
DIAGNOSTIC PROCEDURE .............................. 24
Component Inspection ............................................ 25
EPS MOTOR ....................................................... 25
TROUBLE DIAGNOSIS FOR SYMPTOMS .............. 26
EPS Warning Lamp Does Not Turn ON ................. 26
SYMPTOM: ......................................................... 26
DIAGNOSTIC PROCEDURE .............................. 26
EPS Warning Lamp Does Not Turn OFF ................ 27
PRECAUTIONS
STC-3
[EPS]
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STC
Revision: June 20062007 Versa
PRECAUTIONSPFP:00001
Precautions for Supplemental Restraint System (SRS) “AIR BAG” and “SEAT
BELT PRE-TENSIONER”
UGS000A8
The Supplemental Restraint System such as “AIR BAG” and “SEAT BELT PRE-TENSIONER”, used along
with a front seat belt, helps to reduce the risk or severity of injury to the driver and front passenger for certain
types of collision. This system includes seat belt switch inputs and dual stage front air bag modules. The SRS
system uses the seat belt switches to determine the front air bag deployment, and may only deploy one front
air bag, depending on the severity of a collision and whether the front occupants are belted or unbelted.
Information necessary to service the system safely is included in the SRS and SB section of this Service Man-
ual.
WA RN ING:
To avoid rendering the SRS inoperative, which could increase the risk of personal injury or death
in the event of a collision which would result in air bag inflation, all maintenance must be per-
formed by an authorized NISSAN/INFINITI dealer.
Improper maintenance, including incorrect removal and installation of the SRS, can lead to per-
sonal injury caused by unintentional activation of the system. For removal of Spiral Cable and Air
Bag Module, see the SRS section.
Do not use electrical test equipment on any circuit related to the SRS unless instructed to in this
Service Manual. SRS wiring harnesses can be identified by yellow and/or orange harnesses or
harness connectors.
Precautions Necessary for Steering Wheel Rotation After Battery DisconnectUGS000A9
NOTE:
This Procedure is applied only to models with Intelligent Key system and NVIS/IVIS (NISSAN/INFINITI
VEHICLE IMMOBILIZER SYSTEM - NATS).
Remove and install all control units after disconnecting both battery cables with the ignition knob in the
″LOCK″ position.
Always use CONSULT-II to perform self-diagnosis as a part of each function inspection after finishing
work. If DTC is detected, perform trouble diagnosis according to self-diagnostic results.
For models equipped with the Intelligent Key system and NVIS/IVIS, an electrically controlled steering lock
mechanism is adopted on the key cylinder.
For this reason, if the battery is disconnected or if the battery is discharged, the steering wheel will lock and
steering wheel rotation will become impossible.
If steering wheel rotation is required when battery power is interrupted, follow the procedure below before
starting the repair operation.
OPERATION PROCEDURE
1. Connect both battery cables.
NOTE:
Supply power using jumper cables if battery is discharged.
2. Use the Intelligent Key or mechanical key to turn the ignition switch to the ″ACC″ position. At this time, the
steering lock will be released.
3. Disconnect both battery cables. The steering lock will remain released and the steering wheel can be
rotated.
4. Perform the necessary repair operation.
5. When the repair work is completed, return the ignition switch to the ″LOCK″ position before connecting
the battery cables. (At this time, the steering lock mechanism will engage.)
6. Perform a self-diagnosis check of all control units using CONSULT-II.
STC-4
[EPS]
PRECAUTIONS
Revision: June 20062007 Versa
Service Notice or Precautions for EPS SystemUGS0008F
CAUTION:
Check or confirm the following item when performing the trouble diagnosis.
Check any possible causes by interviewing the symptom and it’s condition from the customer if
any malfunction, such as EPS warning lamp turns ON, occurs.
Check if air pressure and size of tires are proper, the specified part is used for the steering wheel,
and control unit is genuine part.
Check if the connection of steering column assembly and steering gear assembly is proper (there
is not looseness of mounting bolts, damage of rods, boots or sealants, and leakage of grease,
etc).
Check if the wheel alignment is adjusted properly.
Check if there is any damage or modification to suspension or body resulting in increased weight
or altered ground clearance.
Check if installation conditions of each link and suspension are proper.
Check if the battery voltage is proper
Check connection conditions of each connector are proper.
Before connecting or disconnecting the EPS control unit
harness connector, turn ignition switch “OFF” and discon-
nect battery ground cable. Because battery voltage is
applied to EPS control unit even if ignition switch is turned
“OFF”.
When connecting or disconnecting pin connectors into or
from EPS control unit, take care not to damage pin termi-
nals (bend or break).
When connecting pin connectors, make sure that there are
no bends or breaks on EPS control unit pin terminal.
Before replacing EPS control unit, perform EPS control unit
input/output signal inspection and make sure whether EPS
control unit functions properly or not. Refer to STC-11,
"EPS Control Unit Input/Output Signal Reference Values" .
SEF 2 89 H
SEF 2 91 H
SDIA1848E
TROUBLE DIAGNOSIS
STC-11
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Revision: June 20062007 Versa
EPS Control Unit Input/Output Signal Reference ValuesUGS0007X
SPECIFICATIONS WITH CONSULT-II
CAUTION:
The output signal indicates the EPS control unit calculation date. The normal values will be displayed
even in the event that the output circuit (harness) is open.
*1 : In the front of the value, “L” is displayed at steering left and “R” is displayed at steering right.
*2 : Almost in accordance with the value of “MOTOR SIG”. It is not a malfunction though these values are not accorded when steering
quickly.
*3 : It is not a malfunction, though it might not be corresponding just after ignition switch is turned ON.
*4 : It turns to OFF after waiting for a short period of time.Monitor item (Unit) Content Condition Display value
MOTOR VOL (V)Power supply voltage for
EPS control unitIgnition switch: ON Battery voltage
TORQUE SENSOR (Nm)Steering wheel turning
forceEngine runningSteering wheel: Not
steering (There is no
steering force) 0.00 Nm
Steering wheel: Steer-
ing0 – 8.19 Nm
*1 (The value
is changed according to
steering left or right)
MOTOR SIG (A)Command current to EPS
motorEngine runningSteering wheel: Not
steering (There is no
steering force)0.00 A
Steering wheel: Steer-
ing0 – 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: Steer-
ing0 – 65.00 A
*2 (The value
is changed according to
steering left or right)
VEHICLE SPEED (km/h) or (mph) Vehicle speedVehicle stopped 0 km/h (0 mph)
While drivingApproximately equal to
the indication on speed-
ometer (Inside of ±10%)
*3
WARNING LAMP (ON/OFF)EPS warning lamp condi-
tionEPS warning lamp: ON ON
EPS warning lamp: OFF OFF
DERATING STAT (ON/OFF) Protect overload status Engine runningSteering wheel: Nor-
mal steeringOFF
Steering wheel: Steer-
ing over the stopON
*4
ENGINE STATUS (RUN/STOP) Engine statusEngine stopped
(Engine speed: Less than 400 rpm)STOP
Engine running
(Engine speed: 400 rpm or more)RUN
STC-12
[EPS]
TROUBLE DIAGNOSIS
Revision: June 20062007 Versa
SPECIFICATIONS BETWEEN EPS CONTROL UNIT TERMINALS
EPS Control Unit Terminal Connector Layout
Data are reference value and are measured.
CAUTION:
When using a circuit tester to measure voltage for inspection, be sure not to extend forcibly any connector terminals.
SGIA1624E
Te r m i n a lWire
colorItem Condition Data (Approx.)
4 V Torque sensor sub Engine runningSteering wheel: Not steering
(There in no steering force)2.5 V
Steering wheel: Steering1.7 V – 3.3 V
(The value is changed accord-
ing to steering left or right)
5 BR Torque sensor power supplyIgnition switch: ON 8 V
Ignition switch: OFF 0 V
6 G Torque sensor main Engine runningSteering wheel: Not steering
(There is no steering force)2.5 V
Steering wheel: Steering1.7 V – 3.3 V
(The value is changed accord-
ing to steering left or right)
7 R Torque sensor ground Always 0 V
9 L CAN-H — —
10 O Power supplyIgnition switch: ON Battery voltage
Ignition switch: OFF 0 V
16 P CAN-L — —
17 R Power supply (Memory back-up)Ignition switch: ON Battery voltage
Ignition switch: OFF Battery voltage
18 B Ground Always 0 V
19 — Motor (+) — —
20 — Motor (–) — —
TROUBLE DIAGNOSIS
STC-13
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CONSULT-II Function (EPS)UGS0007Y
FUNCTION
CONSULT-II can display each diagnostic item using the diagnostic test modes shown following.
CONSULT-II SETTING PROCEDURE
Refer to GI-38, "CONSULT-II Start Procedure" .
SELF-DIAG RESULTS MODE
Operation Procedure
1. Perform “CONSULT-II Start Procedure”. Refer to GI-38, "CONSULT-II Start Procedure" .
2. With engine at idle, touch “SELF-DIAG RESULTS”. Display
shows malfunction experienced since the last erasing operation.
NOTE:
When malfunction occurred at the same time, it is dis-
played to a 3 system at the maximum.
The details for “TIME” are as follow:
–“0”: Error currently detected with EPS control unit.
–Except for “0”: Error detected in the past and memorized
with EPS control unit.
Detects frequency of driving after DTC occurs (frequency
of turning ignition switch “ON”).
Display Item List
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.
Diagnostic test mode Function Reference page
Self-diagnostic results
Self-diagnostic results can be read and erased quickly.STC-13
Data monitorInput/Output data in the EPS control unit can be read.STC-14
CAN diagnostic support monitorThe results of transmit/receive diagnosis of CAN communication can be read.LAN-44
ECU part numberEPS control unit part number can be read.STC-14
SGIA1531E
Item
(CONSULT-II 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-16, "
DTC C1601
BATTERY VOLT"
TORQUE SENSOR
[C1604]When the torque sensor malfunction assembled in steering column
assembly is detected. STC-19, "DTC C1604
TORQUE SENSOR"
EPS MOTOR
[C1606]When the motor driver malfunction of EPS control unit or EPS motor
malfunction is detected.STC-21, "DTC C1606
EPS MOTOR"
EEPROM
[C1607]When the memory (EEPROM) system malfunction is detected in
EPS control unit.STC-22, "DTC C1607
EEPROM"
CONTROL UNIT
[C1608]When the internal malfunction is detected in EPS control unit.STC-22, "DTC C1608
CONTROL UNIT"
CAN VHCL SPEED
[C1609]When the malfunction is detected in vehicle speed signal received
with CAN communication.STC-23, "DTC C1609
CAN VHCL SPEED"
CAN ENG RPM
[C1610]When the malfunction is detected in engine status signal received
with CAN communication.STC-24, "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-24, "DTC U1000
CAN COMM CIRCUIT"
NO DTC IS DETECTED.
FURTHER TESTING MAY BE
REQUIRED.No NG item has been detected. —
STC-16
[EPS]
TROUBLE DIAGNOSIS FOR SYSTEM
Revision: June 20062007 Versa
TROUBLE DIAGNOSIS FOR SYSTEMPFP:00000
DTC C1601 BATTERY VOLTUGS0008J
CONSULT-II REFERENCE VALUE IN DATA MONITOR MODE
Data are reference value.
EPS CONTROL UNIT TERMINALS AND REFERENCE VALUE
Data are reference value and are measured between each terminal and ground.
CAUTION:
When using a circuit tester to measure voltage for inspection, be sure not to extend forcibly any connector terminals.Monitor item (Unit) Content Condition Display value
MOTOR VOL (V) Power supply voltage for EPS control unit Ignition switch: ON Battery voltage
Terminal Wire color Item Condition Data (Approx.)
10 O Power supplyIgnition switch: ON Battery voltage
Ignition switch: OFF 0 V
17 R Power supply (Memory back-up)Ignition switch: ON Battery voltage
Ignition switch: OFF Battery voltage
18 B Ground Always 0 V
TROUBLE DIAGNOSIS FOR SYSTEM
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DIAGNOSTIC PROCEDURE
1. CHECK EPS CONTROL UNIT POWER SUPPLY CIRCUIT
1. Turn ignition switch “OFF”.
2. Disconnect EPS control unit harness connector.
3. Turn ignition switch “ON”. (Do not start engine.)
4. Check voltage between EPS control unit harness connector (A)
terminals and ground.
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 2.
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-4, "POWER
SUPPLY ROUTING CIRCUIT" .
10 A fuses (No. 2, located in the fuse block). Refer to PG-4, "POWER SUPPLY ROUTING CIR-
CUIT" .
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.
2. 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 3.
NG >> Repair open circuit or short to ground or short to power
in harness or connectors.
Connector Terminal Voltage
M53 10 – Ground Battery voltage
M54 17 – Ground Battery voltage
SGIA1626E
Connector Terminal Voltage
M53 10 – Ground Approx. 0 V
M54 17 – Ground Battery voltage
SGIA1627E
Connector Terminal Continuity
M54 18 Yes
SGIA1628E