2001 INFINITI QX4 Ac system

Circuit DiagramNBAT0008
MAT906A
GI
MA
EM
LC
EC
FE
TF
PD
AX
SU
BR
ST
RS
BT
HA
SC
EL
IDX
OVERALL SYSTEM
Circuit Diagram
AT-13

Cross-sectional ViewNBAT0010
SAT150K
OVERALL SYSTEM
Cross-sectional View
AT-14

Hydraulic Control CircuitNBAT0011
SAT151K
GI
MA
EM
LC
EC
FE
TF
PD
AX
SU
BR
ST
RS
BT
HA
SC
EL
IDX
OVERALL SYSTEM
Hydraulic Control Circuit
AT-15

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.
GI
MA
EM
LC
EC
FE
TF
PD
AX
SU
BR
ST
RS
BT
HA
SC
EL
IDX
OVERALL SYSTEM
Shift Mechanism (Cont'd)
AT-17

POWER TRANSMISSION=NBAT0012S04ªNº and ªPº PositionsNBAT0012S0401IªNº position
No control members operate. Power from the input shaft is not transmitted to the output shaft since the
clutch does not operate.
IªPº position
Similar to the ªNº position, no control members operate. The parking pawl interconnected with the select
lever engages with the parking gear to mechanically hold the output shaft so that the power train is locked.
SAT039J
OVERALL SYSTEM
Shift Mechanism (Cont'd)
AT-18

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
GI
MA
EM
LC
EC
FE
TF
PD
AX
SU
BR
ST
RS
BT
HA
SC
EL
IDX
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