INFINITI QX56 2010 Factory Service Manual

TM-6
< BASIC INSPECTION >
DIAGNOSIS AND REPAIR WORKFLOW
>> GO TO 3.
3.CHECK DTC
1. Check DTC.
2. Perform the following procedure if DTC is detected.
• Record DTC.
• Erase DTC. Refer to TM-30, "
OBD-II Diagnostic Trouble Code (DTC)".
Is any DTC detected?
YES >> GO TO 4.
NO >> GO TO 6.
4.PERFORM DIAGNOSTIC PROCEDURE
Perform “Diagnosis Procedure” for the displayed DTC.
>> GO TO 5.
5.PERFORM DTC CONFIRMATION PROCEDURE
Perform “DTC CONFIRMATION PROCEDURE”.
Is DTC detected?
YES >> GO TO 4.
NO >> GO TO 6.
6.CHECK SYMPTOM 2
Try to confirm the symptom described by the customer.
Is any malfunction present?
YES >> GO TO 7.
NO >> INSPECTION END
7.ROAD TEST
Perform “ROAD TEST”. Refer to TM-159, "
Description".
>> GO TO 8.
8.CHECK SYMPTOM 3
Try to confirm the symptom described by the customer.
Is any malfunction present?
YES >> GO TO 2.
NO >> INSPECTION END
Diagnostic Work SheetINFOID:0000000005148506
INFORMATION FROM CUSTOMER
KEY POINTS• WHAT ..... Vehicle and A/T model
• WHEN ..... Date, Frequencies
• WHERE ..... Road conditions
• HOW ..... Operating conditions, Symptoms
Customer name MR/MS Model and Year VIN
Trans. Model EngineMileage
Malfunction Date Manuf. DateIn Service Date
Frequency † Continuous † Intermittent ( times a day)
Revision: April 20092010 QX56

DIAGNOSIS AND REPAIR WORKFLOWTM-7
< BASIC INSPECTION >
CEF
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DIAGNOSTIC WORK SHEET
Symptoms † Vehicle does not move. ( † Any position † Particular position)
† No up-shift ( † 1st → 2nd † 2nd → 3rd † 3rd → 4th † 4th → 5th)
† No down-shift ( † 5th → 4th † 4th → 3rd † 3rd → 2nd † 2nd → 1st)
† Lock-up malfunction
† Shift point too high or too low.
† Shift shock or slip ( † N → D † N → R † Lock-up † Any drive position)
† Noise or vibration
† No kick down
† No pattern select
† Others
()
A/T CHECK indicator lamp † Continuously lit † Not lit
Malfunction indicator lamp (MIL) † Continuously lit † Not lit
1 †
Read the item on cautions concerning fail-safe and understand the customer's com-
plaint. TM-117
2†
A/T fluid inspection, stall test and line pressure test
† A/T fluid inspection
TM-148
† Leak (Repair leak location.)
† Sta te
† Amount
† Stall test
TM-155
† Torque converter one-way clutch
† Front brake
† High and low reverse clutch
† Low coast brake
† Forward brake
† Reverse brake
† Forward one-way clutch †
1st one-way
clutch
† 3rd one-way
clutch
† Engine
† Line pressure low
† Except for input
clutch and direct
clutch, clutches and
brakes OK
† Line pressure test - Suspected part: TM-157
3†
Perform self-diagnosis. — Check detected items to repair or replace malfunctioning
part. TM-32
4†
Perform road test.
5-1 † Check before engine is started TM-159
5-2† Check at idle TM-159
5-3Cruise test †
Part 1 TM-160† Part 2 TM-162
† Part 3 TM-162
† Check malfunction phenomena to repair or replace malfunctioning part after completing all road test.
Refer to TM-121, "
Symptom Table".
5 † Drive vehicle to check that the malfunction phenomenon has been resolved.
6 † Erase the results of the self-diagnosis from the TCM and the ECM. TM-30
Revision: April 20092010 QX56

TM-8
< FUNCTION DIAGNOSIS >
A/T CONTROL SYSTEM
FUNCTION DIAGNOSIS
A/T CONTROL SYSTEM
Cross-Sectional View (2WD models)INFOID:0000000005148507
1. Front planetary gear2. 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. Rear extension 20. Output shaft
SCIA5267E
Revision: April 20092010 QX56

A/T CONTROL SYSTEMTM-9
< FUNCTION DIAGNOSIS >
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Cross-Sectional View (4WD models)INFOID:0000000005148508
Shift MechanismINFOID:0000000005148509
The automatic transmission uses compact triple planet ary 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
Revision: April 20092010 QX56

TM-10
< FUNCTION DIAGNOSIS >
A/T CONTROL SYSTEM
FUNCTION OF CLUTCH AND BRAKE
CLUTCH AND BAND CHART
1. Front brake 2. Input clutch3. Direct clutch
4. High and low reverse clutch 5. Reverse brake6. Forward brake
7. Low coast brake 8. 1st one-way clutch9. Forward one-way clutch
10. 3rd one-way clutch 11. Front sun gear12. Input shaft
13. Mid internal gear 14. Front internal gear15. Rear carrier
16. Rear sun gear 17. Mid sun gear18. Front carrier
19. Mid carrier 20. Rear internal gear21. Output shaft
22. Parking gear 23. Parking pawl
PCIA0002J
Name of the PartAbbreviation Function
Front brake (1) FR/B Fastens the front sun gear (11).
Input clutch (2) I/CConnects the input shaft (12), the front internal gear (14) and the mid internal
gear (13).
Direct clutch (3) D/C Connects the rear carrier (15) and the rear sun gear (16).
High and low reverse clutch (4) HLR/C Connects the mid sun gear (17) and the rear sun gear (16).
Reverse brake (5) R/B Fastens the rear carrier (15).
Forward brake (6) Fwd/B Fastens the mid sun gear (17).
Low coast brake (7) LC/B Fastens the mid sun gear (17).
1st one-way clutch (8) 1st OWCAllows the rear sun gear (16) to turn freely forward relative to the mid sun gear
(17) but fastens it
for reverse rotation.
Forward one-way clutch (9) Fwd OWCAllows the mid sun gear (17) to turn freely in the forward direction but fastens it
for reverse rotation.
3rd one-way clutch (10) 3rd OWCAllows the front sun gear (11) to turn freely in the forward direction but fastens
it for reverse rotation.
Shift position I/C HLR/C D
/C R/B FR/B LC/B Fwd/B 1st
OWC Fwd
OWC 3rd
OWC Remarks
P PARK POSITION
R REVERSE PO-
SITION
Revision: April 20092010 QX56

A/T CONTROL SYSTEMTM-11
< FUNCTION DIAGNOSIS >
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• —Operates
• —Operates during “pro gressive” acceleration.
• —Operates and effects power transmission while coasting.
• —Line pressure is applied but does not affect power transmission.
• —Operates under conditions shown in HLR/C Operating Condition
• —Operates under conditions shown in LC/B Operating Condition. Delay control is applied during D (4,3,2,1) ⇒N shift.
POWER TRANSMISSION
“N” Position
NNEUTRAL POSI-
TION
D 1st
Automatic shift
1 ⇔ 2⇔ 3⇔ 4⇔ 5
2nd
3rd
4th
5th1st
Automatic shift1⇔ 2⇔ 3⇔ 4
4
2nd
3rd
4th
3 1st
Automatic shift1⇔ 2⇔ 3⇐4
2nd
3rd 4th
2 1st
Automatic shift1⇔ 2⇐3 ⇐4
2nd
3rd
4th
1 1st
Locks (held sta-tionary in 1GR)
1⇐ 2⇐3 ⇐4
2nd
3rd4th
Shift position I/C HLR/C D/C R/B FR/B LC/B Fwd/B
1st
OWC Fwd
OWC 3rd
OWC Remarks
SCIA5642E
Revision: April 20092010 QX56

TM-12
< FUNCTION DIAGNOSIS >
A/T CONTROL SYSTEM
Since both the forward brake and the reverse brake are released, torque from the input shaft drive is not trans-
mitted to the output shaft.
“P” Position
• The same as for the “N” position, both the forward br ake and the reverse brake are released, so torque from
the input shaft drive is not transmitted to the output shaft.
• The parking pawl linked with the select lever meshes with the parking gear and fastens the output shaft mechanically.
“D”, “4”, “3”, “2” Positions 1GR
• The forward brake and the forward one-way clutch regulate reverse rotation of the mid sun gear.
• The 1st one-way clutch regulates reverse rotation of the rear sun gear.
• The 3rd one-way clutch regulates reverse rotation of the front sun gear.
• During deceleration, the mid sun gear turns forward, so the forward one-way clutch idles and the engine
brake is not activated.
1. Front brake 2. Input clutch3. Direct clutch
4. High and low reverse clutch 5. Reverse brake 6. Forward brake
7. Low coast brake 8. 1st one-way clutch 9. Forward one-way clutch
10. 3rd one-way clutch 11. Front sun gear12. Input shaft
13. Mid internal gear 14. Front internal gear15. Rear carrier
16. Rear sun gear 17. Mid sun gear18. Front carrier
19. Mid carrier 20. Rear internal gear21. Output shaft
22. Parking gear 23. Parking pawl
PCIA0003J
Revision: April 20092010 QX56

A/T CONTROL SYSTEMTM-13
< FUNCTION DIAGNOSIS >
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“1” Position 1GR
• The front brake fastens the front sun gear.
• The forward brake and the forward one-way clutch
regulate reverse rotation of the mid sun gear.
• High and low reverse clutch connects the rear sun gear and the mid sun gear.
• The low coast brake fastens the mid sun gear.
• During deceleration, the low coast brake regulates forward rotation of the mid sun gear and the engine brake
functions.
1. Front brake 2. Input clutch3. Direct clutch
4. High and low reverse clutch 5. Reverse brake 6. Forward brake
7. Low coast brake 8. 1st one-way clutch9. Forward one-way clutch
10. 3rd one-way clutch 11. Front sun gear12. Input shaft
13. Mid internal gear 14. Front internal gear15. Rear carrier
16. Rear sun gear 17. Mid sun gear18. Front carrier
19. Mid carrier 20. Rear internal gear21. Output shaft
22. Parking gear 23. Parking pawl
SCIA1512E
Revision: April 20092010 QX56

TM-14
< FUNCTION DIAGNOSIS >
A/T CONTROL SYSTEM
“D”, “4”, “3” Positions 2GR
• The forward brake and the forward one-way clutch regulate reverse rotation of the mid sun gear.
• The 3rd one-way clutch regulates reverse rotation of the front sun gear.
• The direct clutch is coupled and the rear carrier and rear sun gear are connected.
• During deceleration, the mid sun gear turns forward, so the forward one-way clutch idles and engine brake is
not activated.
1. Front brake 2. Input clutch3. Direct clutch
4. High and low reverse clutch 5. Reverse brake 6. Forward brake
7. Low coast brake 8. 1st one-way clutch 9. Forward one-way clutch
10. 3rd one-way clutch 11. Front sun gear12. Input shaft
13. Mid internal gear 14. Front internal gear15. Rear carrier
16. Rear sun gear 17. Mid sun gear18. Front carrier
19. Mid carrier 20. Rear internal gear21. Output shaft
22. Parking gear 23. Parking pawl
SCIA1513E
Revision: April 20092010 QX56

A/T CONTROL SYSTEMTM-15
< FUNCTION DIAGNOSIS >
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“2”, “1” Positions 2GR
• The front brake fastens the front sun gear.
• The forward brake and the forward one-way clutch
regulate reverse rotation of the mid sun gear.
• The direct clutch is coupled, and the rear carrier and rear sun gear are connected.
• The low coast brake fastens the mid sun gear.
• During deceleration, the low coast brake regulates forward rotation of the mid sun gear and the engine brake
functions.
1. Front brake 2. Input clutch3. Direct clutch
4. High and low reverse clutch 5. Reverse brake 6. Forward brake
7. Low coast brake 8. 1st one-way clutch9. Forward one-way clutch
10. 3rd one-way clutch 11. Front sun gear12. Input shaft
13. Mid internal gear 14. Front internal gear15. Rear carrier
16. Rear sun gear 17. Mid sun gear18. Front carrier
19. Mid carrier 20. Rear internal gear21. Output shaft
22. Parking gear 23. Parking pawl
SCIA1514E
Revision: April 20092010 QX56