DIAGNOSIS SENSOR UNITSRS-45
< ON-VEHICLE REPAIR >
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DIAGNOSIS SENSOR UNIT
Removal and InstallationINFOID:0000000005931219
REMOVAL
WARNING:
Before disconnecting diagnosis sensor unit harness connector(s), be sure to disconnect harness con-
nectors from air bag modules and front seat belt pre-tensioner to prevent deployment by static elec-
tricity.
CAUTION:
• Before servicing the SRS, turn th e ignition switch OFF, disconnect both battery terminals and wait at
least three minutes.
• Do not disassemble diagnosis sensor unit.
• Do not use old bolts; replace with new bolts.
• Replace the diagnosis sensor unit if it has been dropped or sustained an impact.
• Check diagnosis sensor unit bracket to make sure it is free of deformities, dents, cracks or rust. If it
shows any visible signs of da mage, replace with new one.
• The diagnosis sensor unit must always be installed with the arrow mark " ⇐" pointing toward the
front of the vehicle for proper operation.
• When replacing the air bag diagno sis sensor unit, always check with the parts department for he lat-
est parts information. Installing an incorrect air bag diagnosis sensor unit may or may not cause the
air bag warning lamp to illuminate and may cause incorrect deployment of the supplemental air bags
and seat belt pre-tensioner in a collision r esulting in serious personal injury or death.
1. Always check the air bag diagnosis sensor unit E CU discriminated number (identification number) using
CONSULT-III.
2. Disconnect the negative and positive battery term inals, then wait at least three minutes.
3. Disconnect the harness connectors for the following SRS components: Refer to SRS-40
(Side Curtain Air
Bag Module), SRS-44
(Front Seat Belt Pre-tensioner), SE-13, "Disassembly and Assembly" (Side Air Bag
Module).
4. Remove center console assembly. Refer to IP-11
.
5. Disconnect diagnosis sensor unit connectors.
6. Remove the bolts and the ground bolt, then remove the diagnosis sensor unit.
INSTALLATION
Installation is in the reverse order of removal.
• The diagnosis sensor unit must always be installed with the arrow mark " ⇐" pointing toward the front of the
vehicle.
• Follow the tightening sequence 1,2,3,4 as shown.
1. Diagnosis sensor unit connectors 2. Ground Bolt 3. Bolt
4. Diagnosis sensor unit Vehicle front
WHIA0323E
Revision: May 2010 2011 Versa
STC-1
STEERING
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CONTENTS
STEERING CONTROL SYSTEM
EPS
BASIC INSPECTION ....... .............................
3
DIAGNOSIS AND REPAIR WORKFLOW ..... .....3
Work Flow ........................................................... ......3
SYSTEM DESCRIPTION ..............................5
EPS SYSTEM ... .............................................. .....5
System Diagram .................................................. ......5
System Description ...................................................5
Component Parts Location ........................................6
Component Description .............................................6
DIAGNOSIS SYSTEM (EPS CONTROL UNIT)
.....
8
CONSULT-III Function ........................................ ......8
DTC/CIRCUIT DIAGNOSIS ..........................9
C1601 BATTERY POWER SUPPLY ..................9
Description .......................................................... ......9
DTC Logic .................................................................9
Diagnosis Procedure .................................................9
C1604 TORQUE SENSOR .................................11
Description ..............................................................11
DTC Logic ...............................................................11
Diagnosis Procedure ...............................................11
C1606 EPS MOTOR ...........................................13
Description .......................................................... ....13
DTC Logic ...............................................................13
Diagnosis Procedure ...............................................13
Component Inspection ............................................13
C1607, C1608 EPS CONTROL UNIT ................15
Description .......................................................... ....15
DTC Logic ...............................................................15
Diagnosis Procedure ...............................................15
C1609 VEHICLE SPEED SIGNAL .....................16
Description ........................................................... ....16
DTC Logic ................................................................16
Diagnosis Procedure ...............................................16
C1610 ENGINE STATUS SIGNAL ...................17
Description ...............................................................17
DTC Logic ................................................................17
Diagnosis Procedure ...............................................17
U1000 CAN COMM CIRCUIT ...........................18
Description ...............................................................18
DTC Logic ................................................................18
Diagnosis Procedure ...............................................18
EPS WARNING LAMP ......................................19
Description ...............................................................19
Component Function Check ....................................19
Diagnosis Procedure ...............................................19
ECU DIAGNOSIS INFORMATION ..............20
EPS CONTROL UNIT .......................................20
Reference Value .................................................. ....20
Wiring Diagram - ELECTRONICALLY CON-
TROLLED POWER STEERING SYSTEM - ............
22
Fail-Safe .............................................................. ....23
DTC Inspection Priority Chart ..................................24
DTC Index ...............................................................24
SYMPTOM DIAGNOSIS ..............................25
EPS WARNING LAMP DOES NOT TURN ON ...25
Description ........................................................... ....25
Diagnosis Procedure ...............................................25
EPS WARNING LAMP DOES NOT TURN
OFF ....................................................................
26
Description ...............................................................26
Diagnosis Procedure ...............................................26
STEERING WHEEL TURNING FORCE IS
HEAVY OR LIGHT ............................................
27
Revision: May 2010 2011 Versa
STC-2
Description ..............................................................27
Diagnosis Procedure ..............................................27
UNBALANCE STEERING WHEEL TURNING
FORCE AND RETURN BETWEEN RIGHT
AND LEFT ..........................................................
28
Description ..............................................................28
Diagnosis Procedure ..............................................28
UNBALANCE STEERING WHEEL TURNING
FORCE (TORQUE VARIATION) .......................
29
Description ........................................................... ...29
Diagnosis Procedure ............................................ ...29
PRECAUTION ............................................30
PRECAUTIONS .............................................. ...30
Precaution for Supplemental Restraint System
(SRS) "AIR BAG" and "SEAT BELT PRE-TEN-
SIONER" .............................................................. ...
30
Precaution Necessary for Steering Wheel Rota-
tion After Battery Disconnect ..................................
30
Service Notice or Precaution for EPS System ........31
Revision: May 2010 2011 Versa
STC-8
< SYSTEM DESCRIPTION >[EPS]
DIAGNOSIS SYSTEM (EPS CONTROL UNIT)
DIAGNOSIS SYSTEM
(EPS CONTROL UNIT)
CONSULT-III FunctionINFOID:0000000005931228
FUNCTION
CONSULT-III can display each diagnostic item us ing the diagnostic test modes shown following.
ECU IDENTIFICATION
Displays the part number stored in the control unit.
SELF-DIAG RESULTS MODE
Display Item List
Refer to STC-24, "DTC Index".
CAUTION:
If “CAN COMM CIRCUIT [U1000]” is disp layed with other DTCs, first perform the trouble diagnosis for
CAN communication line.
DATA MONITOR MODE
Display Item List
*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. Diagnostic test mode
Function
ECU identification Steering column assembly number can be read.
Self diagnostic result Self-diagnostic results can be read and erased quickly.
CAN diag support MNTR The results of transmit/receive diagnosis of CAN communication can be read.
Data monitor Input/Output data in the EPS control unit can be read.
Monitor item (Unit) Remarks
BATTERY VOLT (V) Displays the power supply voltage for EPS control unit.
TORQUE SENSOR (Nm) Displays steering wheel turning force detected by torque sensor.
MOTOR CURRENT (A) Displays the current value consumed by EPS motor.
MOTOR SIG (A)
*1Displays the current commanded value to EPS motor.
VEHICLE SPEED (km/h) or (MPH)
*2Vehicle speed is displayed from vehicle speed signal via CAN communication.
WARNING LAMP (On/Off) EPS warning lamp control status is displayed.
ENGINE STATUS (Stop/Run) Engine speed is displayed from engine status signal via CAN communication.
Revision: May 2010 2011 Versa
C1601 BATTERY POWER SUPPLYSTC-9
< DTC/CIRCUIT DIAGNOSIS > [EPS]
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DTC/CIRCUIT DIAGNOSIS
C1601 BATTERY POWER SUPPLY
DescriptionINFOID:0000000005931229
Power is supplied from the battery to EPS control unit.
DTC LogicINFOID:0000000005931230
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
“C1601” detected?
YES >> Proceed to diagnosis procedure. Refer to STC-9, "Diagnosis Procedure".
NO >> Inspection End.
Diagnosis ProcedureINFOID:0000000005931231
1.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 terminal and ground.
4. Connect EPS control unit harness connector.
Is the inspection result normal?
YES >> GO TO 2.
NO >> Repair open circuit or short to ground or short to power in harness or connectors.
2.CHECK EPS CONTROL UNI T POWER SUPPLY CIRCUIT
1. Check voltage between EPS control unit harness connector terminals and ground.
2. Turn ignition switch ON. CAUTION:
Never start the engine.
3. Check voltage between EPS control unit harness connector terminals and ground.
DTC Display item Malfunction detected condition Possible cause
C1601 BATTERY VOLT When a power supp
ly voltage to the EPS control unit
is maintained at or above 17.5 V or less than 9 V con-
tinuously for more than five seconds. • Harness or connector
• EPS control unit
EPS control unit
—Con tin uit y
Connector Terminal
M54 18Ground Existed
EPS control unit
—Volt a g e
Connector Terminal
M53 10
Ground Approx. 0 V
M54 17 Battery voltage
Revision: May 2010 2011 Versa
STC-10
< DTC/CIRCUIT DIAGNOSIS >[EPS]
C1601 BATTERY POWER SUPPLY
Is the inspection result normal?
YES >> GO TO 3.
NO >> Check the following. If any items are damaged, repair or replace damaged parts.
• 10A fuse (#2) open
- Harness for short between 10A fuse (#2) and pow er steering control unit harness connector No.
10 terminal.
• 60A fusible link (M) open
- Harness for short between 60A fusible link (M) and power steering control unit harness connec-
tor No. 10 terminal.
• Harness for open between ignition switch and power steering control unit harness connector No. 17 terminal.
• Harness for open between battery and power steering control unit harness connector No. 17 ter-
minal.
• Battery or ignition switch.
3.CHECK BATTERY VOLTAGE SIGNAL (1)
With CONSULT-III
1. Connect EPS control unit harness connector.
2. Start the engine. CAUTION:
Stop the vehicle.
3. Select “EPS”, “DATA MONITOR” and “MOTOR VO LT”, and perform the battery voltage inspection.
Is the inspection result normal?
YES >> GO TO 4.
NO >> Replace EPS control unit. Refer to PS-10, "
Removal and Installation".
4.CHECK MOTOR VOLTAGE SIGNAL (2)
With CONSULT-III
Select “MOTOR VOLT” in “DATA MONITOR” of the EPS control unit. Check motor voltage with the steering
wheel fully turned leftward or rightward.
Is the value in
“DATA MONITOR”“between 9 V and 17.5 V”?
YES >> Check pin terminal and connection of each harness connector for damage or loose connection.
NO >> Check battery power supply and ignition power supply. Refer to STC-22, "
Wiring Diagram - ELEC-
TRONICALLY CONTROLLED POWER STEERING SYSTEM -".
EPS control unit
—Volt a ge
Connector Terminal
M53 10
Ground Battery voltage
M54 17
Monitor item ConditionDisplay value
MOTOR VOLT Engine runningBattery voltage
Revision: May 2010 2011 Versa
C1604 TORQUE SENSORSTC-11
< DTC/CIRCUIT DIAGNOSIS > [EPS]
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C1604 TORQUE SENSOR
DescriptionINFOID:0000000005931232
Torque sensor detects the steering torque, and transmit the signal to EPS control unit.
DTC LogicINFOID:0000000005931233
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
“C1604” detected?
YES >> Proceed to diagnosis procedure. Refer to STC-11, "Diagnosis Procedure".
NO >> Inspection End.
Diagnosis ProcedureINFOID:0000000005931234
1.CHECK TORQUE SENSOR POWER SUPPLY CIRCUIT
1. Turn ignition switch OFF to ON. CAUTION:
Never start the engine.
2. Check voltage between EPS control unit harness connector terminals and ground. CAUTION:
Steering wheel is neutral position. (There is no steering force.)
Is the inspection result normal?
YES >> GO TO 2.
NO >> Perform the trouble diagnosis for battery power supply circuit. Refer to STC-9, "
Diagnosis Proce-
dure".
2.CHECK TORQUE SENSOR GROUND CIRCUIT
1. Turn ignition switch OFF.
2. Check continuity between EPS control unit harness connector terminal and ground. CAUTION:
Steering wheel is neutral position. (There is no steering force.)
Is the inspection result normal?
YES >> GO TO 3.
NO >> Repair open circuit or short to ground or short to power in harness or connectors.
DTC Display item Malfunction detected condition Possible cause
C1604 TORQUE SENSOR When torque sensor output signal is malfunctioning. • Harness or connector
• Torque sensor
• EPS control unit
EPS control unit
—Volt a g e
Connector Terminal
M53 5Ground Approx. 5 V
EPS control unit
—Con tin uit y
Connector Terminal
M53 7Ground Yes
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