2001 INFINITI QX4 brake

19. A/T Does Not Shift: 22-> 11, When Selector
Lever²2²->²1²Position .........................................255
20. Vehicle Does Not Decelerate By Engine
Brake........................................................................256
21. TCM Self-diagnosis Does Not Activate (PNP,
Overdrive Control and Throttle Position Switches
Circuit Checks) ........................................................257
A/T SHIFT LOCK SYSTEM.........................................265
Description ...............................................................265
Wiring Diagram - SHIFT -........................................266
Diagnostic Procedure ..............................................267
KEY INTERLOCK CABLE..........................................271
Components.............................................................271
Removal ...................................................................271
Installation ................................................................272
ON-VEHICLE SERVICE..............................................273
Control Valve Assembly and Accumulators .............273
Revolution Sensor Replacement .............................274
Turbine Revolution Sensor Replacement................274
Rear Oil Seal Replacement .....................................274
Rear Oil Seal and Companion Flange Oil Seal
Replacement ............................................................275
Parking Components Inspection..............................275
Park/Neutral Position Switch Adjustment ................276
Manual Control Linkage Adjustment........................276
REMOVAL AND INSTALLATION...............................277
Removal ...................................................................277
Installation ................................................................278
OVERHAUL.................................................................281
Components.............................................................281
Oil Channel ..............................................................284
Locations of Needle Bearings, Thrust Washers
and Snap Rings .......................................................285
DISASSEMBLY............................................................286
REPAIR FOR COMPONENT PARTS.........................297Oil Pump ..................................................................297
Control Valve Assembly ...........................................301
Control Valve Upper Body .......................................307
Control Valve Lower Body .......................................312
Reverse Clutch ........................................................314
High Clutch ..............................................................317
Forward and Overrun Clutches ...............................320
Low & Reverse Brake..............................................324
Forward Clutch Drum Assembly ..............................328
Rear Internal Gear and Forward Clutch Hub ..........330
Band Servo Piston Assembly ..................................333
Parking Pawl Components ......................................337
ASSEMBLY..................................................................339
Assembly (1) ............................................................339
Adjustment ...............................................................347
Assembly (2) ............................................................349
SERVICE DATA AND SPECIFICATIONS (SDS).......356
General Specifications .............................................356
Shift Schedule..........................................................356
Stall Revolution ........................................................356
Line Pressure...........................................................356
Return Springs .........................................................357
Accumulator O-ring ..................................................358
Clutches and Brakes ...............................................358
Oil Pump and Low One-way Clutch ........................360
Total End Play..........................................................360
Reverse Clutch Drum End Play ..............................361
Removal and Installation .........................................361
Shift Solenoid Valves ...............................................361
Solenoid Valves .......................................................361
A/T Fluid Temperature Sensor.................................361
Turbine Revolution Sensor ......................................361
Revolution Sensor ...................................................362
Dropping Resistor ....................................................362GI
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CONTENTS(Cont'd)
AT-3

Shift MechanismNBAT0012The automatic transmission uses compact, dual planetary gear systems to improve power-transmission
efficiency, simplify construction and reduce weight.
It also employs an optimum shift control and superwide gear ratios. They improve starting performance and
acceleration during medium and high-speed operation.
Two one-way clutches are also employed: one is used for the forward clutch and the other for the low clutch.
These one-way clutches, combined with four accumulators, reduce shifting shock to a minimum.
CONSTRUCTIONNBAT0012S01
SAT509I
1. Torque converter clutch piston
2. Torque converter
3. Oil pump
4. Input shaft
5. Brake band
6. Reverse clutch
7. High clutch
8. Front pinion gear9. Front sun gear
10. Front internal gear
11. Front planetary carrier
12. Rear sun gear
13. Rear pinion gear
14. Rear internal gear
15. Rear planetary carrier
16. Forward clutch17. Forward one-way clutch
18. Overrun clutch
19. Low one-way clutch
20. Low & reverse brake
21. Parking pawl
22. Parking gear
23. Output shaft
FUNCTION OF CLUTCH AND BRAKENBAT0012S02
Clutch and brake components Abbr. Function
Reverse clutch6R/C To transmit input power to front sun gear9.
High clutch7H/C To transmit input power to front planetary carrier11.
Forward clutch16F/C To connect front planetary carrier11with forward one-way
clutch17.
Overrun clutch18O/C To connect front planetary carrier11with rear internal gear14.
Brake band5B/B To lock front sun gear9.
Forward one-way clutch17F/O.C When forward clutch16is engaged, to stop rear internal gear
14from rotating in opposite direction against engine revolution.
Low one-way clutch19L/O.C To stop front planetary carrier11from rotating in opposite direc-
tion against engine revolution.
Low & reverse brake20L & R/B To lock front planetary carrier11.
OVERALL SYSTEM
Shift Mechanism
AT-16

CLUTCH AND BAND CHARTNBAT0012S03
Shift positionReverse
clutchHigh
clutchFor-
ward
clutchOver-
run
clutchBand servoFor-
ward
one
-way
clutchLow
one-
way
clutchLow &
reverse
brakeLock-up Remarks
2nd
apply3rd
release4th
apply
PPARK
POSITION
RqqREVERSE
POSITION
NNEUTRAL
POSITION
D*41stq*1D B B
Automatic
shift
1k2k3
k4 2ndq*1AqB
3rdqq*1A *2C C B *5q
4thqC *3C Cqq
21stqDBBAutomatic
shift
1k2 2ndq*1AqB
11stqqBqLocks (held
stationary) in
1st speed
1g2 2ndqqqB
*1: Operates when overdrive control switch is being set in ªOFFº position.
*2: Oil pressure is applied to both 2nd ªapplyº side and 3rd ªreleaseº side of band servo piston. However, brake band does not contract
because oil pressure area on the ªreleaseº side is greater than that on the ªapplyº side.
*3: Oil pressure is applied to 4th ªapplyº side in condition *2 above, and brake band contracts.
*4: A/T will not shift to 4th when overdrive control switch is set in ªOFFº position.
*5: Operates when overdrive control switch is ªOFFº.
q: Operates.
A: Operates when throttle opening is less than 3/16, activating engine brake.
B: Operates during ªprogressiveº acceleration.
C: Operates but does not affect power transmission.
D: Operates when throttle opening is less than 3/16, but does not affect engine brake.
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OVERALL SYSTEM
Shift Mechanism (Cont'd)
AT-17

ª11º Position=NBAT0012S0406
Forward clutch
Forward one-way clutch
Overrun clutch
Low and reverse brakeAs overrun clutch engages, rear internal gear is locked by the operation of low and
reverse brake.
This is different from that of D
1and 21.
Engine brake Overrun clutch always engages, therefore engine brake can be obtained when decelerat-
ing.
SAT100J
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OVERALL SYSTEM
Shift Mechanism (Cont'd)
AT-19

ªD1º and ª21º Positions=NBAT0012S0402
Forward one-way clutch
Forward clutch
Low one-way clutchRear internal gear is locked to rotate counterclockwise because of the functioning of
these three clutches. (Start-up at D
1)
Overrun clutch
engagement conditions
(Engine brake)D
1: Overdrive control switch in ªOFFº
Throttle opening less than 3/16
2
1: Throttle opening less than 3/16
At D
1and 21positions, engine brake is not activated due to free turning of low one-way
clutch.
SAT096J
OVERALL SYSTEM
Shift Mechanism (Cont'd)
AT-20

ªD2º, ª22º and ª12º Positions=NBAT0012S0403
Forward clutch
Forward one-way clutch
Brake bandRear sun gear drives rear planetary carrier and combined front internal gear. Front inter-
nal gear now rotates around front sun gear accompanying front planetary carrier.
As front planetary carrier transfers the power to rear internal gear through forward clutch
and forward one-way clutch, this rotation of rear internal gear increases the speed of
rear planetary carrier compared with that of the 1st speed.
Overrun clutch
engagement conditionsD
2: Overdrive control switch in ªOFFº
Throttle opening less than 3/16
2
2: Throttle opening less than 3/16
1
2: Always engaged
SAT097J
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OVERALL SYSTEM
Shift Mechanism (Cont'd)
AT-21

ªD4º (OD) Position=NBAT0012S0405
High clutch
Brake band
Forward clutch
(Does not affect power transmission)Input power is transmitted to front carrier through high clutch.
This front planetary carrier turns around the sun gear which is fixed by brake band and
makes front internal gear (output) turn faster.
Engine brake At D
4position, there is no one-way clutch in the power transmission line and engine
brake can be obtained when decelerating.
SAT099J
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OVERALL SYSTEM
Shift Mechanism (Cont'd)
AT-23

ªRº Position=NBAT0012S0407
Reverse clutch
Low and reverse brakeFront planetary carrier is stationary because of the operation of low and reverse brake.
Input power is transmitted to front sun gear through reverse clutch, which drives front
internal gear in the opposite direction.
Engine brake As there is no one-way clutch in the power transmission line, engine brake can be
obtained when decelerating.
SAT101J
OVERALL SYSTEM
Shift Mechanism (Cont'd)
AT-24