2007 INFINITI QX56 transmission oil

AT-20
< SERVICE INFORMATION >
A/T CONTROL SYSTEM
Cross-Sectional View (4WD models)
INFOID:0000000003532228
Shift MechanismINFOID:0000000003532229
The automatic transmission uses compact triple planetary gear systems to improve power-transmission effi-
ciency, simplify construction and reduce weight.
It also employs an optimum shift control and super wide gear ratios. They improve starting performance and
acceleration during medium and high-speed operation.
CONSTRUCTION
1. Front planetary gear 2. Mid planetary gear 3. Rear planetary gear
4. Direct clutch 5. High and low reverse clutch 6. Reverse brake
7. Drum support 8. Forward brake 9. Low coast brake
10. Input shaft 11. Torque converter 12. Oil pump
13. Front brake 14. 3rd one-way clutch 15. Input clutch
16. 1st one-way clutch 17. Control valve with TCM 18. Forward one-way clutch
19. Adapter case 20. Output shaft
SCIA5268E

AT-36
< SERVICE INFORMATION >
A/T CONTROL SYSTEM
*1: Full phase real-time feedback control monitors movement of gear ratio at gear change, and controls oil
pressure at real-time to achieve the best gear ratio.
Lock-up ControlINFOID:0000000003532235
The torque converter clutch piston in the torque converter is engaged to eliminate torque converter slip to
increase power transmission efficiency.
The torque converter clutch control valve operation is controlled by the torque converter clutch solenoid valve,
which is controlled by a signal from TCM, and the torque converter clutch control valve engages or releases
the torque converter clutch piston.
Lock-up Operation Condition Table
TORQUE CONVERTER CLUTCH CONTROL VALVE CONTROL
Lock-up Control System Diagram
Lock-up Released
• In the lock-up released state, the torque converter clutch control valve is set into the unlocked state by the
torque converter clutch solenoid and the lock-up apply pressure is drained.
In this way, the torque converter clutch piston is not coupled.
Lock-up Applied
• In the lock-up applied state, the torque converter clutch control valve is set into the locked state by the
torque converter clutch solenoid and lock-up apply pressure is generated.
In this way, the torque converter clutch piston is pressed and coupled.
SMOOTH LOCK-UP CONTROL
PCIA0013E
Select lever D position 4 position 3 position 2 position
Gear position 5 4 4 3 2
Lock-up×–×××
Slip lock-up××–––
PCIA0014E

AT-56
< SERVICE INFORMATION >
TROUBLE DIAGNOSIS
3. Turn ignition switch to “START” position.
Does the engine start in either position?
YES >> Stop the road test and go to AT-168, "Engine Cannot Be Started in "P" or "N" Position".
NO >> GO TO 3.
3.CHECK “P” POSITION FUNCTIONS
1. Move selector lever to “P” position.
2. Turn ignition switch to “OFF” position.
3. Release the parking brake.
4. Push the vehicle forward or backward.
5. Engage the parking brake.
When you push the vehicle with disengaging the parking brake, does it move?
YES >> Enter a check mark at “In “P” Position Vehicle Moves When Pushed” on the diagnostics work-
sheet, then continue the road test.
NO >> GO TO 4.
4.CHECK “N” POSITION FUNCTIONS
1. Start the engine.
2. Move selector lever to “N” position.
3. Release the parking brake.
Does vehicle move forward or backward?
YES >> Enter a check mark at “In “N” Position Vehicle Moves” on the diagnostics worksheet, then con-
tinue the road test.
NO >> GO TO 5.
5.CHECK SHIFT SHOCK
1. Engage the brake.
2. Move selector lever to “D” position.
When the transmission is shifted from
“N” to “D”, is there an excessive shock?
YES >> Enter a check mark at “Large Shock ("N" to "D" Position) on the diagnostics worksheet, then con-
tinue the road test.
NO >> GO TO 6.
6.CHECK “R” POSITION FUNCTIONS
1. Engage the brake.
2. Move selector lever to “R” position.
3. Release the brake for 4 to 5 seconds.
Does the vehicle creep backward?
YES >> GO TO 7.
NO >> Enter a check mark at “Vehicle Does Not Creep Backward In "R" Position” on the diagnostics
worksheet, then continue the road test.
7.CHECK “D” POSITION FUNCTIONS
Inspect whether the vehicle creeps forward when the transmission is put into the “D” position.
Does the vehicle creep forward in the
“D” positions?
YES >> Go to AT-56, "Cruise Test - Part 1", AT-58, "Cruise Test - Part 2", and AT-59, "Cruise Test - Part 3".
NO >> Enter a check mark at “Vehicle Does Not Creep Forward in "D" Position” on the diagnostics work-
sheet, then continue the road test.
Cruise Test - Part 1INFOID:0000000003532251
1.CHECK STARTING OUT FROM D1
1. Drive the vehicle for about 10 minutes to warm up the engine oil and ATF.
Appropriate temperature for the ATF: 50 - 80°C (122 - 176°F)
2. Park the vehicle on a level surface.
3. Move selector lever to “P” position.
4. Start the engine.
5. Move selector lever to “D” position.

TROUBLE DIAGNOSIS
AT-71
< SERVICE INFORMATION >
D
E
F
G
H
I
J
K
L
MA
B
AT
N
O
P
30
Slips/Will
Not en-
gageNo shock at all or the
clutch slips when vehi-
cle changes speed D4
→ D
5.ON vehicle1. Fluid level and stateAT- 5 1
2. Vehicle speed sensor A/T and vehicle speed sensor MTRAT- 1 0 5,
AT-124
3. ATF pressure switch 1 and front brake solenoid valveAT- 1 5 0,
AT-134
4. ATF pressure switch 5 and direct clutch solenoid valveAT- 1 5 4,
AT-138
5. CAN communication lineAT- 9 1
6. Line pressure testAT- 5 1
7. Control valve with TCMAT-210
OFF vehicle8. Torque converterAT-240
9. Oil pump assemblyAT-258
10. Front brake (brake band)AT-240
11. Input clutchAT-262
12. Gear systemAT-228
13. High and low reverse clutchAT-272
31When you press the
accelerator pedal and
shift speed D5 → D4
the engine idles or the
transmission slips.ON vehicle1. Fluid level and stateAT- 5 1
2. Vehicle speed sensor A/T and vehicle speed sensor MTRAT- 1 0 5,
AT-124
3. ATF pressure switch 1 and front brake solenoid valveAT- 1 5 0,
AT-134
4. ATF pressure switch 5 and direct clutch solenoid valveAT- 1 5 4,
AT-138
5. CAN communication lineAT- 9 1
6. Line pressure testAT- 5 1
7. Control valve with TCMAT-210
OFF vehicle8. Torque converterAT-240
9. Oil pump assemblyAT-258
10. Input clutchAT-262
11. Gear systemAT-228
12. High and low reverse clutchAT-272
13. Direct clutchAT-274
No. Items Symptom Condition Diagnostic ItemReference
page

AT-72
< SERVICE INFORMATION >
TROUBLE DIAGNOSIS
32
Slips/Will
Not en-
gageWhen you press the
accelerator pedal and
shift speed D4 → D3
the engine idles or the
transmission slips.ON vehicle1. Fluid level and stateAT- 5 1
2. Vehicle speed sensor A/T and vehicle speed sensor MTRAT- 1 0 5,
AT- 1 2 4
3. ATF pressure switch 3 and input clutch solenoid valveAT- 1 5 2,
AT- 1 3 0
4. ATF pressure switch 1 and front brake solenoid valveAT- 1 5 0,
AT- 1 3 4
5. CAN communication lineAT- 9 1
6. Line pressure testAT- 5 1
7. Control valve with TCMAT- 2 1 0
OFF vehicle8. Torque converter AT- 2 4 0
9. Oil pump assemblyAT- 2 5 8
10. 3rd one-way clutchAT- 2 6 0
11. Gear systemAT- 2 2 8
12. High and low reverse clutchAT- 2 7 2
13. Forward one- way clutch (Parts behind drum support is
impossible to perform inspection by disassembly. Refer to AT-
19, AT- 2 0.)AT- 2 4 0
14. Forward brake (Parts behind drum support is impossible
to perform inspection by disassembly. Refer to AT- 1 9
, AT- 2 0.)AT- 2 4 0
33When you press the
accelerator pedal and
shift speed D3 → D2
the engine idles or the
transmission slips.ON vehicle1. Fluid level and stateAT- 5 1
2. Vehicle speed sensor A/T and vehicle speed sensor MTRAT- 1 0 5,
AT- 1 2 4
3. ATF pressure switch 6, high and low reverse clutch sole-
noid valveAT- 1 5 6,
AT- 1 4 2
4. ATF pressure switch 5 and direct clutch solenoid valveAT- 1 5 4,
AT- 1 3 8
5. CAN communication lineAT- 9 1
6. Line pressure testAT- 5 1
7. Control valve with TCMAT- 2 1 0
OFF vehicle8. Torque converterAT- 2 4 0
9. Oil pump assemblyAT- 2 5 8
10. 3rd one-way clutchAT- 2 6 0
11. Gear systemAT- 2 2 8
12. Direct clutchAT- 2 7 4
13. Forward brake (Parts behind drum support is impossible
to perform inspection by disassembly. Refer to AT- 1 9
, AT- 2 0.)AT- 2 4 0
No. Items Symptom Condition Diagnostic ItemReference
page

TROUBLE DIAGNOSIS
AT-73
< SERVICE INFORMATION >
D
E
F
G
H
I
J
K
L
MA
B
AT
N
O
P
34
Slips/Will
Not En-
gageWhen you press the
accelerator pedal and
shift speed D2 → D1
the engine idles or the
transmission slips.ON vehicle1. Fluid level and stateAT- 5 1
2. Vehicle speed sensor A/T and vehicle speed sensor MTRAT- 1 0 5,
AT-124
3. ATF pressure switch 5 and direct clutch solenoid valveAT- 1 5 4,
AT-138
4. CAN communication lineAT- 9 1
5. Line pressure testAT- 5 1
6. Control valve with TCMAT-210
OFF vehicle7. Torque converterAT-240
8. Oil pump assemblyAT-258
9. 3rd one-way clutchAT-260
10. 1st one-way clutchAT-267
11. Gear systemAT-228
12. Reverse brakeAT-240
13. Forward one- way clutch (Parts behind drum support is
impossible to perform inspection by disassembly. Refer to AT-
19, AT- 2 0.)AT-240
14. Forward brake (Parts behind drum support is impossible
to perform inspection by disassembly. Refer to AT- 1 9
, AT- 2 0.)AT-240
35With selector lever in
“D” position, accelera-
tion is extremely poor.ON vehicle1. Fluid level and stateAT- 5 1
2. Line pressure testAT- 5 1
3. Accelerator pedal position sensorAT- 11 7
4. CAN communication lineAT- 9 1
5. PNP switchAT- 9 9
6. Control cable adjustmentAT-208
7. Control valve with TCMAT-210
OFF vehicle8. Torque converterAT-240
9. Oil pump assemblyAT-258
10. 1st one-way clutchAT-267
11. Gear systemAT-228
12. Reverse brakeAT-240
13. Forward one- way clutch (Parts behind drum support is
impossible to perform inspection by disassembly. Refer to AT-
19, AT- 2 0.)AT-240
14. Forward brake (Parts behind drum support is impossible
to perform inspection by disassembly. Refer to AT- 1 9
, AT- 2 0.)AT-240
No. Items Symptom Condition Diagnostic ItemReference
page

AT-80
< SERVICE INFORMATION >
TROUBLE DIAGNOSIS
56
OthersMaximum speed low.ON vehicle1. Fluid level and stateAT- 5 1
2. Line pressure testAT- 5 1
3. Accelerator pedal position sensorAT- 11 7
4. CAN communication lineAT- 9 1
5. Direct clutch solenoid valveAT- 1 3 8
6. Control valve with TCMAT- 2 1 0
OFF vehicle7. Torque converterAT- 2 4 0
8. Oil pump assemblyAT- 2 5 8
9. Input clutchAT- 2 6 2
10. Gear systemAT- 2 2 8
11. High and low reverse clutchAT- 2 7 2
12. Direct clutchAT- 2 7 4
13. Forward one- way clutch (Parts behind drum support is
impossible to perform inspection by disassembly. Refer to AT-
19, AT- 2 0.)AT- 2 4 0
14 Forward brake (Parts behind drum support is impossible to
perform inspection by disassembly. Refer to AT- 1 9
, AT- 2 0.)AT- 2 4 0
57 Extremely large creep.ON vehicle1. Engine idle speed EC-75

2. CAN communication lineAT- 9 1
3. ATF pressure switch 5AT- 1 5 4
OFF vehicle 4. Torque converterAT- 2 4 0
58With selector lever in
“P” position, vehicle
does not enter parking
condition or, with se-
lector lever in another
position, parking con-
dition is not cancelled.
Refer to AT-168, "
In
"P" Position, Vehicle
Moves When
Pushed".ON vehicle1. PNP switchAT- 9 9
2. Control cable adjustmentAT- 2 0 8
OFF vehicle 3. Parking pawl componentsAT- 2 2 8
59Vehicle runs with
transmission in “P” po-
sition.ON vehicle1. PNP switchAT- 9 9
2. Fluid level and stateAT- 5 1
3. Control cable adjustmentAT- 2 0 8
4. Control valve with TCMAT- 2 1 0
5. Parking pawl componentsAT- 2 2 8
OFF vehicle 6. Gear systemAT- 2 2 8
No. Items Symptom Condition Diagnostic ItemReference
page

TROUBLE DIAGNOSIS FOR SYMPTOMS
AT-169
< SERVICE INFORMATION >
D
E
F
G
H
I
J
K
L
MA
B
AT
N
O
P
Even though the selector lever is set in the “P” position, the parking mechanism is not actuated,
allowing the vehicle to be moved when it is pushed.
DIAGNOSTIC PROCEDURE
1.CHECK PNP SWITCH CIRCUIT
Perform self-diagnosis. Refer to AT-83, "
CONSULT-II Function (A/T)".
Do the self-diagnosis results indicate PNP switch?
YES >> Check the malfunctioning system. Refer to AT- 9 9.
NO >> GO TO 2.
2.CHECK CONTROL CABLE
Check the control cable.
• Refer to AT-208, "
Checking of A/T Position".
OK or NG
OK >> GO TO 3.
NG >> Adjust control cable. Refer to AT-208, "
Adjustment of A/
T Position".
3.CHECK A/T FLUID CONDITION
1. Remove oil pan. Refer to AT-210, "
Control Valve with TCM and A/T Fluid Temperature Sensor 2".
2. Check A/T fluid condition. Refer to AT-13, "
Checking Automatic
Transmission Fluid (ATF)".
OK or NG
OK >>INSPECTION END
NG >> GO TO 4.
4.DETECT MALFUNCTIONING ITEM
• Check the malfunction items. If any items are damaged, repair or replace damaged parts. Refer to AT-60,
"Symptom Chart" (Symptom No.58).
OK or NG
OK >>INSPECTION END
NG >> Repair or replace damaged parts.
In "N" Position, Vehicle MovesINFOID:0000000003532451
SYMPTOM:
Vehicle moves forward or backward when selecting “N” position.
DIAGNOSTIC PROCEDURE
1.CHECK PNP SWITCH CIRCUIT
Perform self-diagnosis. Refer to AT-83, "
CONSULT-II Function (A/T)".
Do the self-diagnostic results indicate PNP switch?
YES >> Check the malfunctioning system. Refer to AT- 9 9.
NO >> GO TO 2.
2.CHECK CONTROL CABLE
LCIA0345E
SCIA5199E