
STEERING
A
SECTION
STEERING CONTROL SYSTEM
STC B
C
D
E
CONTENTS
BASIC INSPECTION ................................... 2
. ECU DIAGNOSIS ........................................ 15
. F
DIAGNOSIS AND REPAIR WORKFLOW ......... 2
. POWER STEERING CONTROL UNIT .............. 15
Work Flow ................................................................ 2
. Reference Value .....................................................15. STC
Wiring Diagram -- ELECTRONICALLY CON-
FUNCTION DIAGNOSIS .............................. 3
. TROLLED POWER STEERING SYSTEM -- .........16 .
Fail Safe .................................................................19
.
EPS SYSTEM ..................................................... 3
. H
System Diagram ....................................................... 3
. SYMPTOM DIAGNOSIS ............................. 21
.
System Description .................................................. 3
.
Component Parts Location ....................................... 4
. UNBALANCE STEERING WHEEL TURNING I
Component Description ............................................ 5
. FORCE (TORQUE VARIATION) ....................... 21
Description ..............................................................21
.
COMPONENT DIAGNOSIS ......................... 6
. Diagnosis Procedure ..............................................21 .
J
POWER SUPPLY AND GROUND CIRCUIT ...... 6
. PRECAUTION ............................................. 22
.
Description ............................................................... 6
.
Diagnosis Procedure ................................................ 6
. PRECAUTIONS ................................................. 22 K
Precautions for Supplemental Restraint System
POWER STEERING SOLENOID VALVE .......... 8
. (SRS) "AIR BAG" and "SEAT BELT PRE-TEN-
Description ............................................................... 8
. SIONER" ................................................................22
.
Diagnosis Procedure ................................................ 8
. L
Precautions Necessary for Steering Wheel Rota-
ENGINE SPEED SIGNAL CIRCUIT ..................10
. tion after Battery Disconnect ..................................22 .
Description ............................................................. 10
. REMOVAL AND INSTALLATION .............. 23
. M
Diagnosis Procedure .............................................. 10.
EPS CONTROL UNIT ....................................... 23
VEHICLE SPEED SIGNAL CIRCUIT ................13
. Removal and Installation ........................................23
.
Description ............................................................. 13
. N
Diagnosis Procedure .............................................. 13.
O
P
Revision: July 2007 STC-1 2008 Altima
DIAGNOSIS AND REPAIR WORKFLOW
< BASIC INSPECTION >
BASIC INSPECTION
DIAGNOSIS AND REPAIR WORKFLOW
Work Flow INFOID:0000000001346421
DETAILED FLOW
1.COLLECT THE INFORMATION FROM THE CUSTOMER
It is also important to clarify customer complaints before inspection. First of all, reproduce symptoms, and
understand them fully. Ask customer about his/her complaints carefully. In some cases, it will be necessary to
check symptoms by driving vehicle with customer.
>> GO TO 2.
2.BASIC INSPECTION
1. Check the power steering fluid leakage and the power steering fluid level. Refer to ST-8, "Inspection".
2. Check the drive belt tension. Refer to EM-16, "Checking Drive Belts" (QR25DE), EM-121, "Checking
Drive Belts" (VQ35DE).
3. Check the power steering gear for damages, cracks and oil leakage. Refer to ST-8, "Inspection".
4. Check the relief oil pressure. Refer to ST-12, "Inspection".
>> GO TO 3.
3.TROUBLE DIAGNOSIS FOR SYMPTOM
Perform the diagnosis by symptom. Refer to STC-21, "Description".
>> GO TO 4.
4.FINAL CHECK
Check the input/output standard values for the power steering control unit.
Are the power steering control unit input/output values within standard ranges respectively?
YES >> INSPECTION END
NO >> GO TO 2.
Revision: July 2007 STC-2 2008 Altima
EPS SYSTEM
< FUNCTION DIAGNOSIS >
FUNCTION DIAGNOSIS A
EPS SYSTEM
System Diagram INFOID:0000000001346422
B
CONTROL DIAGRAM
C
D
E
F
STC
H
JSGIA0119GB
System Description INFOID:0000000001346423
I