belt INFINITI QX56 2011 Factory Service Manual

ST-50
< REMOVAL AND INSTALLATION >
POWER STEERING OIL PUMP
Note the following, and install in the reverse order of removal.
 When installing suction hoses (1), refer to the figure.CAUTION:
 Never apply fluid to the hose (1) and tube (2).
 Insert hose securely until it contacts spool (A) of tube.
 Leave clearance (L) when installing clamp (3).
 When installing eye bolt (1) and copper washer (2) to oil pump (3), refer to the figure.
CAUTION:
 Never reuse copper washer.
 Apply power steering fluid to around copper washers, then
install eye bolt.
 Install eye bolt with eye join t (assembled to high pressure
hose) (B) protrusion (A) facing with pump side cutout, and
then tighten it to the specifi ed torque after tightening by
hand. Refer to ST-54, "
Exploded View".
 Securely insert harness connector to pressure sensor.
 About the installation of drive belt. Refer to EM-20,
"TensionAdjustment".
 Check fluid level, fluid leakage and air bleeding hydr aulic system after the installation. Refer to ST-30,
"Inspection".
Disassembly and AssemblyINFOID:0000000006225613
DISASSEMBLY
CAUTION:
 Fix oil pump with a vise if necessary.
 Use copper plates when fixing with a vise.
1. Perform inspection before disassembly. Refer to ST-52, "
Inspection".
2. Remove rear cover mounting bolts, and then remove rear cover from body assembly.
3. Remove gasket from body assembly.
4. Remove dowel pin, cartridge and side plate from body assembly.
5. Remove pulley mounting nut and washer, then remove pulley from drive shaft.
6. Remove snap ring from drive shaft and press out it. CAUTION:
When removing snap ring, be careful not to damage drive
shaft.
7. Remove oil seal from body assembly using a suitable tool.
8. Remove O-ring from body assembly.
9. Remove mounting bolts of suction pipe, and then remove suc- tion pipe and bracket from body assembly.
10. Remove connector bolt, and then remove O-ring, flow control
valve and spring from body assembly
11. Perform inspection after disassembly. Refer to ST-52, "
Inspec-
tion".
ASSEMBLY
CAUTION:
 Fix oil pump with a vise if necessary.
 Use copper plates when fixing with a vise.L : 3 – 8 mm (0.12 – 0.31 in)
JSGIA0118ZZ
JSGIA0452ZZ
SST010B
Revision: 2010 May2011 QX56

ST-52
< REMOVAL AND INSTALLATION >
POWER STEERING OIL PUMP
6. Install rotor to body assembly.CAUTION:
When installing rotor, turn mark face on rotor to body
assembly.
7. Install vane to rotor so that arc of vane faces cam ring side.
8. Check if drive shaft assembly turns smoothly.
9. Install gasket to body assembly. CAUTION:
Never reuse gasket.
10. Install rear cover to body assembly, and then tighten mounting bolts to the specified torque.
11. Install pulley and washer to drive shaft, and then tighten lock nut at the specified torque.
12. Apply recommended fluid to O-ring. Install flow control valve spring, flow control valve and O-ring to body assembly, and then
tighten connector bolt to the specified torque.
CAUTION:
Never reuse O-ring.
13. Apply recommended fluid to O-ring, and then install O-ring to body assembly. CAUTION:
Never reuse O-ring.
14. Install suction pipe and bracket to body assembly.
15. Perform inspection after assembly. Refer to ST-52, "
Inspection".
InspectionINFOID:0000000006225614
INSPECTION BEFORE DISASSEMBLY
Disassemble oil pump only when the following malfunctions occur.
 If oil leakage is found on oil pump.
 Oil pump pulley is damaged or deformed.
 Performance of oil pump is low.
INSPECTION AFTER DISASSEMBLY
Body Assembly and Rear Cover Inspection
Check body assembly and rear cover for internal damage. Replace oil pump assembly if necessary.
Cartridge Assembly Inspection
Check cam ring, rotor and vane for damage. Replace oil pump assembly if necessary.
Side Plate Inspection
Check side plate for damage. Replace oil pump assembly if necessary.
Flow Control Valve Inspection
Check flow control valve and spring for damage. Replace oil pump assembly if necessary.
INSPECTION AFTER ASSEMBLY
Relief Oil Pressure
CAUTION:
Make sure that belt tension is normal before starting the following procedure.
SGIA0989E
SST843A
Revision: 2010 May2011 QX56

POWER STEERING OIL PUMPST-53
< REMOVAL AND INSTALLATION >
C
DE
F
H I
J
K L
M A
B
ST
N
O P
1. Connect the oil pressure gauge [SST: KV48103500 (J-26357)] and the oil pressure gauge adapter [SST: KV48102500 (J-
33914)] between oil pump discharge connector and high-pres-
sure hose. Bleed air from the hydraulic circuit while opening
valve fully. Refer to ST-30, "
Inspection".
2. Start engine. Run engine until oil temperature reaches 50 to 80°C (122 to 176 °F).
CAUTION:
 Leave the valve of the oil pressure gauge fully open while
starting and running engine. If engine is started with the
valve closed, the hydraulic pressure in oil pump goes up
to the relief pressure along with unusual increase of oil
temperature.
 Be sure to keep hose clear of belts and other parts when engine is started.
3. Fully close the oil pressure gauge valve with engine at idle and measure the relief oil pressure.
CAUTION:
Never keep valve closed for 10 seconds or longer.
4. Open the valve slowly after measuring. Repair oil pump if the relief oil pressure is outside the standard. Refer to ST-50, "
Disassembly and Assembly".
5. Disconnect the oil pressure gauge from hydraulic circuit.
6. When installing eye bolt (1) and copper washer (2) to oil pump (3), refer to the figure.
CAUTION:
 Never reuse copper washers.
 Apply power steering fluid to around copper washer, theninstall eye bolt.
 Install eye bolt with eye join t (assembled to high pressure
hose) (B) protrusion (A) facing with pump side cutout, and
then tighten it to the specifi ed torque after tightening by
hand. Refer to ST-54, "
Exploded View".
 Securely insert harness connector to pressure sensor.
7. Check fluid level, fluid leakage and air bleeding hydraulic sys- tem after the installation. Refer to ST-30, "
Inspection".
Relief oil pressure : Refer to
ST-58, "
Relief Oil Pres-
sure".
SGIA1225E
JSGIA0452ZZ
Revision: 2010 May2011 QX56

STC-1
STEERING
C
DE
F
H I
J
K L
M
SECTION STC
A
B
STC
N
O P
CONTENTS
STEERING CONTROL SYSTEM
PRECAUTION ................ ...............................2
PRECAUTIONS .............................................. .....2
Precaution for Supplemental Restraint System
(SRS) "AIR BAG" and "SEAT BELT PRE-TEN-
SIONER" ............................................................. ......
2
Precaution Necessary for Steering Wheel Rota-
tion after Battery Disconnect .....................................
2
SYSTEM DESCRIPTION ..............................4
COMPONENT PARTS ................................... .....4
Component Parts Location .................................. ......4
Component Description .............................................4
Power Steering Control Unit ......................................4
Power Steering Solenoid Valve .................................4
SYSTEM ..............................................................5
EPS SYSTEM ........................................ ......................5
EPS SYSTEM : System De scription .........................5
EPS SYSTEM : Fail-Safe ..........................................6
ECU DIAGNOSIS INFO RMATION ...............8
POWER STEERING CONTROL UNIT ........... .....8
Reference Value ................................................. ......8
Fail-Safe ....................................................................9
WIRING DIAGRAM ......................................10
ELECTRONICALLY CONTROLLED POWER
STEERING SYSTEM ...................................... ....
10
Wiring Diagram ................................................... ....10
BASIC INSPECTION ...................................13
DIAGNOSIS AND REPAIR WORK FLOW .......13
Work Flow ............................................................ ....13
DTC/CIRCUIT DIAGNOSIS .........................14
POWER SUPPLY AND GROUND CIRCUIT ....14
Diagnosis Procedure ........................................... ....14
POWER STEERING SOLENOID VALVE .........16
Component Function Check ....................................16
Diagnosis Procedure ...............................................16
Component Inspection .............................................17
ENGINE SPEED SIGNAL CIRCUIT ..................18
Diagnosis Procedure ........................................... ....18
VEHICLE SPEED SIGNAL CIRCUIT ................20
Diagnosis Procedure ...............................................20
SYMPTOM DIAGNOSIS ..............................22
UNBALANCE STEERING WHEEL TURNING
FORCE (TORQUE VARIATION) .......................
22
Description ........................................................... ....22
Diagnosis Procedure ...............................................22
REMOVAL AND INSTALLATION ...............23
POWER STEERING CONTROL UNIT ..............23
Removal and Installation ..................................... ....23
Revision: 2010 May2011 QX56

STC-2
< PRECAUTION >
PRECAUTIONS
PRECAUTION
PRECAUTIONS
Precaution for Supplemental Restraint System (SRS) "AIR BAG" and "SEAT BELT
PRE-TENSIONER"
INFOID:0000000006303358
The Supplemental Restraint System such as “A IR BAG” and “SEAT BELT PRE-TENSIONER”, used along
with a front seat belt, helps to reduce the risk or severi ty 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 w hether the front occupants are belted or unbelted.
Information necessary to service the system safely is included in the “SRS AIR BAG” and “SEAT BELT” of this
Service Manual.
WARNING:
• To avoid rendering the SRS inopera tive, which could increase the risk of personal injury or death in
the event of a collision that would result in air bag inflation, all maintenance must be performed by
an authorized NISS AN/INFINITI dealer.
 Improper maintenance, including in correct removal and installation of the SRS, can lead to personal
injury caused by unintent ional activation of the system. For re moval of Spiral Cable and Air Bag
Module, see the “SRS AIR BAG”.
 Do not use electrical test equipmen t on any circuit related to the SRS unless instructed to in this
Service Manual. SRS wiring harnesses can be identi fied by yellow and/or orange harnesses or har-
ness connectors.
PRECAUTIONS WHEN USING POWER TOOLS (AIR OR ELECTRIC) AND HAMMERS
WARNING:
 When working near the Air Bag Diagnosis Sensor Unit or other Air Bag System sensors with the ignition ON or engine running, DO NOT use air or electric power tools or strike near the sensor(s)
with a hammer. Heavy vibration could activate the sensor(s) and deploy the air bag(s), possibly
causing serious injury.
 When using air or electric power tools or hammers , always switch the ignition OFF, disconnect the
battery, and wait at least 3 minu tes before performing any service.
Precaution Necessary for Steering W heel Rotation after Battery Disconnect
INFOID:0000000006303360
NOTE:
 Before removing and installing any control units, first tu rn the push-button ignition switch to the LOCK posi-
tion, then disconnect bot h battery cables.
 After finishing work, confirm that all control unit connectors are connected properly, then re-connect both
battery cables.
 Always use CONSULT-III to perform self-diagnosis as a part of each function inspection after finishing work.
If a DTC is detected, perform trouble diagnos is according to self-diagnosis results.
For vehicle with steering lock unit, if the battery is disconnected or discharged, the steering wheel will lock and
cannot be turned.
If turning the steering wheel is required with the bat tery disconnected or discharged, follow the operation pro-
cedure below before starting the repair operation.
OPERATION PROCEDURE
1. Connect both battery cables. NOTE:
Supply power using jumper cables if battery is discharged.
2. Turn the push-button ignition switch to ACC position. (At this time, the steering lock will be released.)
3. Disconnect both battery cables. The steering lock wi ll remain released with both battery cables discon-
nected and the steering wheel can be turned.
4. Perform the necessary repair operation.
Revision: 2010 May2011 QX56

DIAGNOSIS AND REPAIR WORK FLOWSTC-13
< BASIC INSPECTION >
C
DE
F
H I
J
K L
M A
B
STC
N
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BASIC INSPECTION
DIAGNOSIS AND REPAIR WORK FLOW
Work FlowINFOID:0000000006256124
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 is necessary to
check symptoms by driving vehicle with customer.
CAUTION:
Customers are not professional. It is danger ous to make an easy guess like “maybe the customer
means that...,” or “maybe the cu stomer mentions this symptom”.
>> GO TO 2.
2.CHECK THE STATUS
1. Power steering fluid leakage and check the power steering fluid level. Refer to ST-30, "
Inspection".
2. Check the drive belt tension. Refer to EM-20, "
Checking".
3. Check the power steering gear for damages, cracks and fluid leakage. Refer to ST-46, "
Inspection".
4. Check the relief oil pressure. Refer to ST-52, "
Inspection".
>> GO TO 3.
3.DIAGNOSIS CHART BY SYMPTOM
Perform the diagnosis by symptom. Refer to STC-22, "
Diagnosis Procedure".
>> 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: 2010 May2011 QX56

STR-1
ENGINE
C
DE
F
G H
I
J
K L
M
SECTION STR
A
STR
N
O P
CONTENTS
STARTING SYSTEM
PRECAUTION ................ ...............................2
PRECAUTIONS .............................................. .....2
Precaution for Supplemental Restraint System
(SRS) "AIR BAG" and "SEAT BELT PRE-TEN-
SIONER" ............................................................. ......
2
Precaution Necessary for Steering Wheel Rota-
tion after Battery Disconnect .....................................
2
PREPARATION ............................................4
PREPARATION .............................................. .....4
Special Service Tools .......................................... ......4
Commercial Service Tools ........................................4
SYSTEM DESCRIPTION ..............................5
COMPONENT PARTS ................................... .....5
Component Parts Location .................................. ......5
Component Description ............................................5
SYSTEM ..............................................................6
System Diagram .................................................. ......6
System Description ...................................................6
WIRING DIAGRAM .......................................7
STARTING SYSTEM ...................................... .....7
Wiring Diagram ................................................... ......7
BASIC INSPECTION ...................................11
DIAGNOSIS AND REPAIR WORKFLOW ........11
Work Flow ............................................................ ....11
DTC/CIRCUIT DIAGNOSIS .........................14
B TERMINAL CIRCUIT .....................................14
Diagnosis Procedure ........................................... ....14
S CONNECTOR CIRCUIT .................................15
Diagnosis Procedure ...............................................15
SYMPTOM DIAGNOSIS ..............................16
STARTING SYSTEM .........................................16
Symptom Table ................................................... ....16
REMOVAL AND INSTALLATION ...............17
STARTER MOTOR ...........................................17
Exploded View ..................................................... ....17
Removal and Installation .........................................18
Inspection ................................................................18
SERVICE DATA AND SPECIFICATIONS
(SDS) ............... .............................................
20
SERVICE DATA AND SPECIFICATIONS
(SDS) .................................................................
20
Starter Motor .......................................................
Revision: 2010 May2011 QX56

STR-2
< PRECAUTION >
PRECAUTIONS
PRECAUTION
PRECAUTIONS
Precaution for Supplemental Restraint System (SRS) "AIR BAG" and "SEAT BELT
PRE-TENSIONER"
INFOID:0000000006275515
The Supplemental Restraint System such as “A IR BAG” and “SEAT BELT PRE-TENSIONER”, used along
with a front seat belt, helps to reduce the risk or severi ty 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 w hether the front occupants are belted or unbelted.
Information necessary to service the system safely is included in the “SRS AIR BAG” and “SEAT BELT” of this
Service Manual.
WARNING:
• To avoid rendering the SRS inopera tive, which could increase the risk of personal injury or death in
the event of a collision that would result in air bag inflation, all maintenance must be performed by
an authorized NISS AN/INFINITI dealer.
 Improper maintenance, including in correct removal and installation of the SRS, can lead to personal
injury caused by unintent ional activation of the system. For re moval of Spiral Cable and Air Bag
Module, see the “SRS AIR BAG”.
 Do not use electrical test equipmen t on any circuit related to the SRS unless instructed to in this
Service Manual. SRS wiring harnesses can be identi fied by yellow and/or orange harnesses or har-
ness connectors.
PRECAUTIONS WHEN USING POWER TOOLS (AIR OR ELECTRIC) AND HAMMERS
WARNING:
 When working near the Air Bag Diagnosis Sensor Unit or other Air Bag System sensors with the ignition ON or engine running, DO NOT use air or electric power tools or strike near the sensor(s)
with a hammer. Heavy vibration could activate the sensor(s) and deploy the air bag(s), possibly
causing serious injury.
 When using air or electric power tools or hammers , always switch the ignition OFF, disconnect the
battery, and wait at least 3 minu tes before performing any service.
Precaution Necessary for Steering W heel Rotation after Battery Disconnect
INFOID:0000000006275516
NOTE:
 Before removing and installing any control units, first tu rn the push-button ignition switch to the LOCK posi-
tion, then disconnect bot h battery cables.
 After finishing work, confirm that all control unit connectors are connected properly, then re-connect both
battery cables.
 Always use CONSULT-III to perform self-diagnosis as a part of each function inspection after finishing work.
If a DTC is detected, perform trouble diagnos is according to self-diagnosis results.
For vehicle with steering lock unit, if the battery is disconnected or discharged, the steering wheel will lock and
cannot be turned.
If turning the steering wheel is required with the bat tery disconnected or discharged, follow the operation pro-
cedure below before starting the repair operation.
OPERATION PROCEDURE
1. Connect both battery cables. NOTE:
Supply power using jumper cables if battery is discharged.
2. Turn the push-button ignition switch to ACC position. (At this time, the steering lock will be released.)
3. Disconnect both battery cables. The steering lock wi ll remain released with both battery cables discon-
nected and the steering wheel can be turned.
4. Perform the necessary repair operation.
Revision: 2010 May2011 QX56

TM-1
TRANSMISSION & DRIVELINE
CEF
G H
I
J
K L
M
SECTION TM
A
B
TM
N
O P
CONTENTS
TRANSAXLE & TRANSMISSION
7AT: RE7R01B
PRECAUTION ................ ...............................
6
PRECAUTIONS .............................................. .....6
Precaution for Supplemental Restraint System
(SRS) "AIR BAG" and "SEAT BELT PRE-TEN-
SIONER" ............................................................. ......
6
General Precautions .................................................6
Service Notice or Precaution .....................................7
PREPARATION ............................................8
PREPARATION .............................................. .....8
Special Service Tool ........................................... ......8
Commercial Service Tool ..........................................9
SYSTEM DESCRIPTION .............................10
COMPONENT PARTS ................................... ....10
A/T CONTROL SYSTEM ...........................................10
A/T CONTROL SYSTEM : Component Parts Lo-
cation ................................................................... ....
10
A/T CONTROL SYSTEM : Component Descrip-
tion ...................................................................... ....
11
A/T CONTROL SYSTEM : TCM .............................12
A/T CONTROL SYSTEM : Transmission Range
Switch .................................................................. ....
12
A/T CONTROL SYSTEM : Input Speed Sensor .....12
A/T CONTROL SYSTEM : Output Speed Sensor ....12
A/T CONTROL SYSTEM : A/ T Fluid Temperature
Sensor ................................................................. ....
12
A/T CONTROL SYSTEM : Input Clutch Solenoid
Valve ................................................................... ....
12
A/T CONTROL SYSTEM : Front Brake Solenoid
Valve ................................................................... ....
12
A/T CONTROL SYSTEM : Direct Clutch Solenoid
Valve ................................................................... ....
12
A/T CONTROL SYSTEM : High and Low Reverse
Clutch Solenoid Valve ......................................... ....
13
A/T CONTROL SYSTEM : Low Brake Solenoid
Valve .................................................................... ....
13
A/T CONTROL SYSTEM : Anti-interlock Solenoid
Valve ........................................................................
13
A/T CONTROL SYSTEM : 2346 Brake Solenoid
Valve ........................................................................
13
A/T CONTROL SYSTEM : Torque Converter
Clutch Solenoid Valve ......................................... ....
13
A/T CONTROL SYSTEM : Line Pressure Solenoid
Valve .................................................................... ....
13
A/T CONTROL SYSTEM : Accelerator Pedal Po-
sition Sensor ........................................................ ....
13
A/T CONTROL SYSTEM : Manual Mode Switch ....13
A/T CONTROL SYSTEM : To w Mode Switch .........14
A/T CONTROL SYSTEM : A/T CHECK Indicator
Lamp .................................................................... ....
14
A/T CONTROL SYSTEM : Tow Mode Indicator
Lamp .................................................................... ....
14
A/T CONTROL SYSTEM : Selector Lever Position
Indicator ............................................................... ....
14
A/T SHIFT LOCK SYSTEM ................................... ....14
A/T SHIFT LOCK SYSTEM : Component Parts
Location ...................................................................
15
A/T SHIFT LOCK SYSTEM : Component Descrip-
tion ...........................................................................
15
STRUCTURE AND OPERATION .....................16
TRANSMISSION .................................................... ....16
TRANSMISSION : Cross-Sectional View ................16
TRANSMISSION : System Diagram ........................18
TRANSMISSION : System Description ...................18
TRANSMISSION : Component Description .............41
FLUID COOLER & FLUID WARMER SYSTEM .... ....41
FLUID COOLER & FLUID WARMER SYSTEM :
System Description ..................................................
41
SYSTEM ............................................................44
A/T CONTROL SYSTEM ....................................... ....44
Revision: 2010 May2011 QX56

TM-6
< PRECAUTION >[7AT: RE7R01B]
PRECAUTIONS
PRECAUTION
PRECAUTIONS
Precaution for Supplemental Restraint S
ystem (SRS) "AIR BAG" and "SEAT BELT
PRE-TENSIONER"
INFOID:0000000006226734
The Supplemental Restraint System such as “A IR BAG” and “SEAT BELT PRE-TENSIONER”, used along
with a front seat belt, helps to reduce the risk or severi ty 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 w hether the front occupants are belted or unbelted.
Information necessary to service the system safely is included in the “SRS AIR BAG” and “SEAT BELT” of this
Service Manual.
WARNING:
• To avoid rendering the SRS inopera tive, which could increase the risk of personal injury or death in
the event of a collision that would result in air bag inflation, all maintenance must be performed by
an authorized NISS AN/INFINITI dealer.
 Improper maintenance, including in correct removal and installation of the SRS, can lead to personal
injury caused by unintent ional activation of the system. For re moval of Spiral Cable and Air Bag
Module, see the “SRS AIR BAG”.
 Do not use electrical test equipmen t on any circuit related to the SRS unless instructed to in this
Service Manual. SRS wiring harnesses can be identi fied by yellow and/or orange harnesses or har-
ness connectors.
PRECAUTIONS WHEN USING POWER TOOLS (AIR OR ELECTRIC) AND HAMMERS
WARNING:
 When working near the Air Bag Diagnosis Sensor Unit or other Air Bag System sensors with the ignition ON or engine running, DO NOT use air or electric power tools or strike near the sensor(s)
with a hammer. Heavy vibration could activate the sensor(s) and deploy the air bag(s), possibly
causing serious injury.
 When using air or electric power tools or hammers , always switch the ignition OFF, disconnect the
battery, and wait at least 3 minu tes before performing any service.
General PrecautionsINFOID:0000000006226735
Turn ignition switch OFF an d disconnect the battery cable
from the negative terminal before connecting or disconnect-
ing the A/T assembly connector. Because battery voltage is
applied to TCM even if igniti on switch is turned OFF.
 Perform “DTC (Diagnostic Trouble Code) CONFIRMATION
PROCEDURE” after performing each TROUBLE DIAGNOSIS.
If the repair is completed DTC should not be displayed in the
“DTC CONFIRMATION PROCEDURE”.
 Always use the specified brand of ATF. Refer to MA-10, "
Fluids
and Lubricants".
 Use lint-free paper not cloth rags during work.
 Dispose of the waste oil using the methods prescribed by law, ordi-
nance, etc. after replacing the ATF.
 Before proceeding with disassembly, thoroughly clean the outside of the transmission. It is important to prevent the internal parts from
becoming contaminated by dirt or other foreign matter.
SEF289H
SEF217U
Revision: 2010 May2011 QX56