2011 INFINITI QX56 manual transmission

SYSTEMTM-47
< SYSTEM DESCRIPTION > [7AT: RE7R01B]
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A/T CONTROL SYSTEM : Protection ControlINFOID:0000000006226770
The TCM becomes the protection control status temporar ily to protect the safety when the safety of TCM and
transmission is lost. It automatically returns to the normal status if the safety is secured.
The TCM has the following protection control.
REVERSE INHIBIT CONTROL
Intercepts the torque transmission and shift to the neutral stat us if the selector lever is shifted to “R” position
while the vehicle moves forward at the vehicle speed 10 km/h (7 MPH) or more.
1ST ENGINE BRAKE PROTECTION CONTROL
Controls the engine brake so as not to make effective by turning the front brake solenoid output to OFF when
each solenoid becomes the electricity pattern of 1st engine brake during driving at the vehicle speed 25 km/h
or more in any positions other than “R” position and 1GR.
TCM HIGH TEMPERATURE PROTECTION CONTROL
Limit the accelerator opening and forcibly control the vehi cle to the low torque driving when the electronic sub-
strate in TCM reaches the high temperature.
P1730 —  Neutral
 Manual mode is prohibited  The shifting between the gears
of 1 - 2 - 3 can be performed
 Manual mode is prohibited Locks in 1GR
 The shifting between the gears
of 2 - 3 - 4 can be performed
 The shifting between the gears
of 3 - 4 can be performed
 The shifting between the gears of 4 - 5 - 6 can be performed
 Manual mode is prohibited
P1815 — Manual mode is prohibited — Manual mode is prohibited
U0300
U1000 Between
the gears of 1 - 2 - 3  The shifting between the gears
of 1 - 2 - 3 can be performed
 Manual mode is prohibited —
 The shifting between the gears
of 1 - 2 - 3 can be performed
 Line pressure is set to the maxi-
mum hydraulic pressure
 Manual mode is prohibited
Between
the gears of 4 - 5 - 6 - 7  Fix the gear at driving
 Manual mode is prohibited
—
P0720 and
P1721 — Locks in 5GR — Locks in 5GR
DTC
Veh ic le
condition Vehicle behavior for 1st fail-safe Vehicle behavior for 2nd fail-safe Vehicle behavior for final fail-safe
Malfunction detection condition Vehicle speed: 10 km/h (7 MPH) or more
Control at malfunction Neutral
Normal return condition  Vehicle speed: 8 km/h (5 MPH) or less
and
 Engine speed: 2,200 rpm or less
Vehicle behavior  The torque transmission cannot be performed
 There is a shock just before a vehicle stop
Malfunction detection condition Select lever and gear: Any position other than “R” position and 1GR
and
 Vehicle speed: More than 25 km/h (16 MPH)
Control at malfunction Front brake solenoid output signal; OFF
Normal return condition Other than detection condition of malfunction
Vehicle behavior Does not exist
Revision: 2010 May2011 QX56

SYSTEMTM-51
< SYSTEM DESCRIPTION > [7AT: RE7R01B]
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*: This signal is transmitted via communication line.
The clutch pressure control solenoid is controlled by the signals from the switches and sensors. Thus, the
clutch pressure is adjusted to be appropriate to t he engine load state and vehicle driving state. It becomes
possible to finely control the clutch hydraulic pressu re with high precision and a smoother shift change charac-
teristic is attained.
The clutch is controlled with the optimum timing and oil pressure by the engine speed, engine torque informa-
tion, etc.
Shift Change System Diagram
*1: Full phase real-time feedback control monitors move ment of gear ratio at gear change, and controls oil
pressure in real-time to achieve the best gear ratio.
BLIPPING CONTROL
This system makes transmission clutch engage readily by controlling (synchronizing) engine revolution
according to the (calculation of) engine revolution after shifting down.
 “BLIPPING CONTROL” functions.
- When downshifting by accelerator pedal depression.
- When downshifting by the manual mode.
PCIA0012E
PCIA0013E
JSDIA0826GB
Revision: 2010 May2011 QX56

TM-56
< SYSTEM DESCRIPTION >[7AT: RE7R01B]
SYSTEM
Input/Output Signal Chart
*: This signal is transmitted via CAN communication line.
 The TCM receives the manual mode signal, non-manual mode signal, manual mode shift up signal and
manual mode shift down signal from combination meter via CAN communication line. The TCM shifts shift
pattern control to the manual mode based on these signal s, and then shifts the A/T by operating each sole-
noid valve according to the shift operation of the driver.
 The TCM prohibits the manual mode while being in fail-safe mode due to an A/T malfunction, etc. Refer to TM-74, "
Fail-Safe".
Manual Mode Information
 The TCM transmits the manual mode shift refusal signal to the combination meter if the TCM refuses the
transmission from the driving status of vehicle when the selector lever shifts to “UP (+ side)” or “DOWN (−
side)” side. The combination meter blinks shift indicator on the combination meter and sounds the buzzer to
indicate the driver that the shifting is not performed when receiving this signal. However, the TCM does not
transmit the manual mode shift refusal signal in the conditions as per the following.
- When the selector lever shifts to “DOWN ( − side)” side in 1GR.
- When the selector lever shifts to “UP (+ side)” side in 7GR.
LOCK-UP CONTROL
LOCK-UP CONTROL : System DiagramINFOID:0000000006226777
LOCK-UP CONTROL : System DescriptionINFOID:0000000006226778
 The torque converter clutch piston in the torque conv erter is engaged to eliminate torque converter slip to
increase power transmission efficiency.
 Lock-up operation, however, is prohibited when A/T fluid temperature is too low.
 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.
Item Signal TCM function Actuator
Output speed sensor Vehicle speed
Manual mode High and low reverse clutch
solenoid valve
 Direct clutch solenoid valve
 Input clutch solenoid valve
 Low brake solenoid valve
 2346 brake solenoid valve
 Front brake solenoid valve
 Torque converter clutch sole- noid valve
 Line pressure solenoid valve
 Anti-interlock solenoid valve
A/T fluid temperature sensor ATF temperature
ECM
Engine speed signal*
Accelerator pedal position sig-
nal*
Combination meter Manual mode signal*
Non-manual mode signal*
Manual mode shift up signal*
Manual mode shift down signal*
JSDIA1350GB
Revision: 2010 May2011 QX56

TM-64
< SYSTEM DESCRIPTION >[7AT: RE7R01B]
DIAGNOSIS SYSTEM (TCM)
TRG PRE 2346/B
(kPa, kg/cm2 or psi)—— Displays the target oil pressure value of 2346
brake solenoid valve calculated by the oil pres-
sure calculation process of shift change control.
SHIFT PATTERN — — Displays the gear change data using the shift
pattern control.
VEHICLE SPEED (km/h or mph) — — Displays the vehicle speed for control using the
control of TCM.
G SEN SLOPE (%) X — Displays the inclination angle calculated by the
G sensor signal received via CAN communica-
tion.
RANGE SW 4 (ON/OFF) X — Displays the operation status of transmission
range switch 4.
RANGE SW 3 (ON/OFF) X — Displays the operation status of transmission
range switch 3.
RANGE SW 2 (ON/OFF) X — Displays the operation status of transmission
range switch 2.
RANGE SW 1 (ON/OFF) X — Displays the operation status of transmission
range switch 1.
SFT DWN ST SW (ON/OFF) X —  Displays the operation status of paddle
shifter (down switch).
 Not mounted but displayed.
SFT UP ST SW (ON/OFF) X —  Displays the operation status of paddle
shifter (up switch).
 Not mounted but displayed.
DOWN SW LEVER (ON/OFF) X — Displays the operation status of selector lever
(down switch).
UP SW LEVER (ON/OFF) X — Displays the operation status of selector lever
(up switch).
NON M-MODE SW (ON/OFF) X — Displays whether the selector lever is in any po-
sition other than manual shift gate position.
MANU MODE SW (ON/OFF) X — Displays whether the selector lever is in the
manual shift gate position.
TOW MODE SW (ON/OFF) — — Displays the reception status of tow mode
switch signal received via CAN communication.
DS RANGE (ON/OFF) — —  Displays whether it is the DS mode.
 Not mounted but displayed.
1 POSITION SW (ON/OFF) X —  Displays the reception status of 1 position
switch signal received via CAN communica-
tion.
 Not mounted but displayed.
OD CONT SW (ON/OFF) X —  Displays the reception status of overdrive
control switch signal received via CAN com-
munication.
 Not mounted but displayed.
BRAKESW (ON/OFF) X — Displays the reception status of stop lamp
switch signal received via CAN communication.
POWERSHIFT SW (ON/OFF) X —  Displays the reception status of POWER
mode signal received via CAN communica-
tion.
 Not mounted but displayed.
Monitored item (Unit)
Monitor Item Selection
Remarks
ECU IN-
PUT SIG- NALS MAIN SIG-
NALS SELEC-
TION
FROM ITEM
Revision: 2010 May2011 QX56

DIAGNOSIS SYSTEM (TCM)TM-65
< SYSTEM DESCRIPTION > [7AT: RE7R01B]
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ASCD-OD CUT (ON/OFF) X — Displays the reception status of ASCD OD can-
cel request signal received via CAN communi-
cation.
ASCD-CRUISE (ON/OFF) X — Displays the reception status of ASCD opera-
tion signal received via CAN communication.
ABS SIGNAL (ON/OFF) X — Displays the re
ception status of ABS operation
signal received via CAN communication.
TCS GR/P KEEP (ON/OFF) X — Displays the reception status of TCS gear keep
request signal received via CAN communica-
tion.
TCS SIGNAL 2 (ON/OFF) X — Displays whether the reception value of A/T
shift schedule change demand signal received
via CAN communication is “cold”.
TCS SIGNAL 1 (ON/OFF) X — Displays whether the reception value of A/T
shift schedule change demand signal received
via CAN communication is “warm”.
LOW/B PARTS (FAIL/NOTFAIL) — — Displays whether the identified malfunction
point judged by TCM is the related parts of low
brake.
HC/IC/FRB PARTS (FAIL/NOTFAIL) — — Displays whether the identified malfunction
point judged by TCM is the related parts of high
and low reversed clutch, input clutch or front
brake.
IC/FRB PARTS (FAIL/NOTFAIL) — — Displays whether the identified malfunction
point judged by TCM is the related parts of input
clutch or front brake.
HLR/C PARTS (FAIL/NOTFAIL) — — Displays whether the identified malfunction
point judged by TCM is the related parts of high
and low reversed clutch.
W/O THL POS (ON/OFF) X — Displays the kickdown condition signal status
received via CAN communication.
CLSD THL POS (ON/OFF) X — Displays the idling status signal status received
via CAN communication.
DRV CST JUDGE (DRIVE/COAST) — — Displays the judgment results of “driving” or
“coasting” judged by TCM.
SHIFT IND SIGNAL — — Displays the transmission value of shift position
signal transmitted via CAN communication.
STARTER RELAY (ON/OFF) — — Displays the command status from TCM to
starter relay.
F-SAFE IND/L (ON/OFF) — — Displays the transmission status of A/T CHECK
indicator lamp signal transmitted via CAN com-
munication.
ATF WARN LAMP (ON/OFF) — — Displays the transmission status of ATF tem-
perature signal transmitted via CAN communi-
cation.
MANU MODE IND (ON/OFF) — — Displays the transmission status of manual
mode signal transmitted via CAN communica-
tion.
ON OFF SOL MON (ON/OFF) — — Monitors the command value from TCM to the
anti-interlock solenoid, and displays the moni-
tor status.
Monitored item (Unit)
Monitor Item Selection
Remarks
ECU IN-
PUT SIG- NALS MAIN SIG-
NALS SELEC-
TION
FROM ITEM
Revision: 2010 May2011 QX56

TM-76
< ECU DIAGNOSIS INFORMATION >[7AT: RE7R01B]
TCM
Protection Control
INFOID:0000000006226784
The TCM becomes the protection control status temporar ily to protect the safety when the safety of TCM and
transmission is lost. It automatically returns to the normal status if the safety is secured.
The TCM has the following protection control.
REVERSE INHIBIT CONTROL
Intercepts the torque transmission and shift to the neutral stat us if the selector lever is shifted to “R” position
while the vehicle moves forward at the vehicle speed 10 km/h (7 MPH) or more.
P0730 —  Manual mode is prohibited
Neutral  The shifting between the gears
of 1 - 2 - 3 can be performed
 Manual mode is prohibited  Locks in 1GR
 The shifting between the gears
of 1 - 2 can be performed
 The shifting between the gears
of 1 - 2 - 3 can be performed
 Manual mode is prohibited
P0740 —  Lock-up is prohibited
 Slip lock-up is prohibited — Lock-up is prohibited
 Slip lock-up is prohibited
P0744 —  Lock-up is prohibited
 Slip lock-up is prohibited
— Lock-up is prohibited
 Slip lock-up is prohibited
P0750
P0775
P0795
P2713
P2722
P2731
P2807 —
 Locks in 2GR, 3GR, 4GR, 5GR,
6GR or 7GR
 Manual mode is prohibited — Locks in 1GR
 The shifting between the gears
of 1 - 2 - 3 can be performed
 The shifting between the gears of 3 - 4 - 5 can be performed
 The shifting between the gears
of 4 - 5 - 6 can be performed
 The shifting between the gears of 1 - 2 - 3 - 4 - 5 - 6 can be per-
formed
 Manual mode is prohibited
P0780 —  Manual mode is prohibited
Neutral — The shifting between the gears
of 1 - 2 - 3 can be performed
 Manual mode is prohibited
P1705 —  Downshift when accelerator ped-
al is depressed is prohibited
 Upshift when accelerator pedal
is released is prohibited
 Manual mode is prohibited  Downshift when accelerator ped-
al is depressed is prohibited
 Upshift when accelerator pedal
is released is prohibited
 Manual mode is prohibited  Downshift when accelerator ped-
al is depressed is prohibited
 Upshift when accelerator pedal
is released is prohibited
 Manual mode is prohibited
P1730 — Neutral
 Manual mode is prohibited  The shifting between the gears
of 1 - 2 - 3 can be performed
 Manual mode is prohibited  Locks in 1GR
 The shifting between the gears
of 2 - 3 - 4 can be performed
 The shifting between the gears of 3 - 4 can be performed
 The shifting between the gears of 4 - 5 - 6 can be performed
 Manual mode is prohibited
P1815 — Manual mode is prohibited — Manual mode is prohibited
U0300
U1000 Between
the gears of
1 - 2 - 3  The shifting between the gears
of 1 - 2 - 3 can be performed
 Manual mode is prohibited —
 The shifting between the gears
of 1 - 2 - 3 can be performed
 Line pressure is set to the maxi- mum hydraulic pressure
 Manual mode is prohibited
Between
the gears of 4 - 5 - 6 - 7  Fix the gear at driving
 Manual mode is prohibited
—
P0720 and
P1721 — Locks in 5GR — Locks in 5GR
DTC
Vehicle
condition Vehicle behavior for 1st fail-safe Vehicle behavior for 2nd fail-safe Vehicle behavior for final fail-safe
Revision: 2010 May2011 QX56

TM-114
< DTC/CIRCUIT DIAGNOSIS >[7AT: RE7R01B]
P0729 6GR INCORRECT RATIO
P0729 6GR INCORRECT RATIO
DescriptionINFOID:0000000006226815
This malfunction is detected when the A/T does not shift
into 6GR position as instructed by TCM. This is not
only caused by electrical malfunction (circuits open or s horted) but by mechanical malfunction such as control
valve sticking, improper solenoid valve operation, etc.
DTC LogicINFOID:0000000006226816
DTC DETECTION LOGIC
DTC CONFIRMATION PROCEDURE
CAUTION:
“ TM-115, "
Diagnosis Procedure"” must be performed before starting “DTC CONFIRMATION PROCE-
DURE”.
 Never perform “DTC CONFIRMATION PROCEDURE” before completing the repair, which may cause secondary malfunction.
 Always drive vehicle at a safe speed.
1.PRECONDITIONING
If “DTC CONFIRMATION PROCEDURE” is previously c onducted, always turn ignition switch OFF and wait at
least 10 seconds before performing the next test.
>> GO TO 2.
2.CHECK ATF TEMPERATURE
With CONSULT-III
1. Start the engine.
2. Select “ATF TEMP 1” in “Data Monitor” in “TRANSMISSION”.
3. Check ATF temperature is in the following range.
With GST
1. Start the engine.
2. Drive vehicle for approximately 5 minutes in urban areas.
Is ATF temperature within specified range?
YES >> GO TO 3.
NO >> Drive vehicle to warm ATF or stop engine to cool ATF.
3.CHECK SYMPTOM (PART 1)
With CONSULT-III
1. Select “6TH GR FNCTN P0729” in “DTC & SRT confirmation” in “TRANSMISSION”.
2. Drive vehicle with manual mode and maintain the following conditions.
DTC Trouble diagnosis name DTC is detected if... Possible cause
P0729 Gear 6 Incorrect Ratio The gear ratio is:
 0.915 or more
 0.813 or less Input clutch solenoid valve
 Direct clutch solenoid valve
 High and low reverse clutch
solenoid valve
 Front brake solenoid valve
 Low brake solenoid valve
 2346 brake solenoid valve
 Anti-interlock solenoid valve
 Each clutch and brake
 Output speed sensor
 Input speed sensor 1, 2
 Hydraulic co ntrol circuit
ATF TEMP 1 : 20 °C (68 °F) – 140 °C (284 °F)
Revision: 2010 May2011 QX56

TM-118
< DTC/CIRCUIT DIAGNOSIS >[7AT: RE7R01B]
P0731 1GR INCORRECT RATIO
P0731 1GR INCORRECT RATIO
DescriptionINFOID:0000000006226821
This malfunction is detected when the A/T does not shift
into 1GR position as instructed by TCM. This is not
only caused by electrical malfunction (circuits open or s horted) but by mechanical malfunction such as control
valve sticking, improper solenoid valve operation, etc.
DTC LogicINFOID:0000000006226822
DTC DETECTION LOGIC
DTC CONFIRMATION PROCEDURE
CAUTION:
“ TM-119, "
Diagnosis Procedure"” must be performed before starting “DTC CONFIRMATION PROCE-
DURE”.
 Never perform “DTC CONFIRMATION PROCEDURE” before completing the repair, which may cause secondary malfunction.
 Always drive vehicle at a safe speed.
1.PRECONDITIONING
If “DTC CONFIRMATION PROCEDURE” is previously c onducted, always turn ignition switch OFF and wait at
least 10 seconds before performing the next test.
>> GO TO 2.
2.CHECK ATF TEMPERATURE
With CONSULT-III
1. Start the engine.
2. Select “ATF TEMP 1” in “Data Monitor” in “TRANSMISSION”.
3. Check ATF temperature is in the following range.
With GST
1. Start the engine.
2. Drive vehicle for approximately 5 minutes in urban areas.
Is ATF temperature within specified range?
YES >> GO TO 3.
NO >> Drive vehicle to warm ATF or stop engine to cool ATF.
3.CHECK SYMPTOM (PART 1)
With CONSULT-III
1. Select “1ST GR FNCTN P0731” in “DTC & SRT confirmation” in “TRANSMISSION”.
2. Drive vehicle with manual mode and maintain the following conditions.
DTC Trouble diagnosis name DTC is detected if... Possible cause
P0731 Gear 1 Incorrect Ratio The gear ratio is:
 5.180 or more
 4.594 or less Input clutch solenoid valve
 Direct clutch solenoid valve
 High and low reverse clutch
solenoid valve
 Front brake solenoid valve
 Low brake solenoid valve
 2346 brake solenoid valve
 Anti-interlock solenoid valve
 Each clutch and brake
 Output speed sensor
 Input speed sensor 1, 2
 Hydraulic co ntrol circuit
ATF TEMP 1 : 20 °C (68 °F) – 140 °C (284 °F)
Revision: 2010 May2011 QX56