Infiniti QX56 (Z62). Manual - part 1284

SYSTEM

TM-45

< SYSTEM DESCRIPTION >

[7AT: RE7R01B]

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• Transmit required output signals to the respective solenoids.

A/T CONTROL SYSTEM : Fail-Safe

INFOID:0000000006226769

TCM has the electrical fail-safe mode. The mode is divided into a maximum of 3 phases (1st fail-safe, 2nd fail-
safe and final fail-safe) and functions so that the operation can be continued even if the signal circuit of the
main electronically controlled input/output parts is damaged.
Even if the electronic circuit is normal, the fail-safe mode may start under special conditions (such as when the
brake pedal is depressed suddenly from a hard wheel spin status to stop the rotation of wheels). In this case,
turn the ignition switch OFF and back to ON after 5 seconds to resume the normal shift pattern.
Consequently, the customer's vehicle may already return to the normal condition. Refer to 

TM-88, "Diagnosis

Flow"

.

FAIL-SAFE FUNCTION

1st Fail-Safe

The mode that the vehicle can stop safely, to prompt the driver to stop if the malfunction occurs and to shift to 
2nd fail-safe early. It shifts to 2nd fail-safe or final fail-safe after the vehicle stopped.

2nd Fail-Safe

The mode that the vehicle shifts to final fail-safe without changing the behavior, by identifying the malfunction-
ing parts in the condition that the driving force required for the driving is secured.

Final Fail-Safe

• Selects the shifting pattern that the malfunctioning parts identified at 1st fail-safe and 2nd fail-safe are not 

used, and then secure the driving force that is required for the driving.

• The mode that the shifting performance does not decrease by normal shift control.

DTC

Vehicle 

condition

Vehicle behavior for 1st fail-safe

Vehicle behavior for 2nd fail-safe

Vehicle behavior for final fail-safe

P0615

—

Starter is disabled

—

Starter is disabled

P0705

—

• Fixed in the “D” position (The 

shifting can be performed)

• 30 km/h (19MPH) or less
• Lock-up is prohibited
• The shifting between the gears 

of 3 - 4 - 5 - 6 - 7 can be per-
formed 

• Manual mode is prohibited
• Shift position indicator is 

switched OFF

• Starter relay is switched OFF 

(starter is disabled)

• Back-up lamp is OFF
• Large shift shock

—

• Fixed in the “D” position (The 

shifting can be performed)

• 30 km/h (19 MPH) or less
• Lock-up is prohibited
• The shifting between the gears 

of 3 - 4 - 5 - 6 - 7 can be per-
formed 

• Manual mode is prohibited
• Shift position indicator is 

switched OFF

• Starter relay is switched OFF 

(starter is disabled)

• Back-up lamp is OFF
• Large shift shock

P0710

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

• Manual mode is prohibited

Between 

the gears of 

4 - 5 - 6 - 7

• Fix the gear while driving
• Manual mode is prohibited

—

P0717

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

• Manual mode is prohibited

Between 

the gears of 

4 - 5 - 6 - 7

• Fix the gear while driving
• Manual mode is prohibited

—

TM-46

< SYSTEM DESCRIPTION >

[7AT: RE7R01B]

SYSTEM

P0720

Between 

the gears of 

1 - 2 - 3

• Only downshift can be per-

formed

• Manual mode is prohibited
• A vehicle speed signal from the 

combination meter is regarded 
as an effective signal

—

• The shifting between the gears 

of 1 - 2 - 3 can be performed

• Manual mode is prohibited

Between 

the gears of 

4 - 5 - 6 - 7

• Fix the gear at driving
• Manual mode is prohibited
• A vehicle speed signal from the 

combination meter is regarded 
as an effective signal

—

P0729
P0731
P0732
P0733
P0734
P0735
P1734

Neutral 
malfunction 
between 
the gears of 
1 - 2 - 3 and 
7

• Locks  in  4GR
• Manual mode is prohibited
• Neutral

—

• 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

• The shifting between the gears 

of 4 - 5 - 6 can be performed

• Manual mode is prohibited

Other than 
the above

• Driving with the gear ratio be-

tween 1GR and 2GR

• Driving with the gear ratio be-

tween 2GR and 3GR

• Locks  in  3GR
• Locks  in  4GR
• Fix the gear while driving
• 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

• 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

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

DTC

Vehicle 

condition

Vehicle behavior for 1st fail-safe

Vehicle behavior for 2nd fail-safe

Vehicle behavior for final fail-safe

SYSTEM

TM-47

< SYSTEM DESCRIPTION >

[7AT: RE7R01B]

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A/T CONTROL SYSTEM : Protection Control

INFOID:0000000006226770

The TCM becomes the protection control status temporarily 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 status 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 vehicle 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

Vehicle 

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

TM-48

< SYSTEM DESCRIPTION >

[7AT: RE7R01B]

SYSTEM

LINE PRESSURE CONTROL

LINE PRESSURE CONTROL : System Diagram

INFOID:0000000006226771

LINE PRESSURE CONTROL : System Description

INFOID:0000000006226772

• When an engine and A/T integrated control signal (engine torque) equivalent to the engine drive force is

transmitted from the ECM to the TCM, the TCM controls the line pressure solenoid valve.
This line pressure solenoid controls the pressure regulator valve as the signal pressure and adjusts the pres-
sure of the operating oil discharged from the oil pump to the line pressure most appropriate to the driving
state.

• The TCM has stored in memory a number of patterns for the optimum line pressure characteristic for the

driving state.

• In order to obtain the most appropriate line pressure characteristic to meet the current driving state, the TCM

controls the line pressure solenoid current value and thus controls the line pressure.

Normal Control

Each clutch is adjusted to the necessary pressure to match the
engine drive force.

Back-up Control (Engine Brake)

Malfunction detection condition

TCM electronic substrate temperature
• 145

°

C (293

°

F) and 120 seconds

or

• 150

°

C (302

°

F)

Control at malfunction

Accelerator opening: 0.5/8 or less

Normal return condition

• TCM electronic substrate temperature: Less than 140

°

C (284

°

F)

and

• Vehicle speed: 5 km/h (3 MPH) or less

Vehicle behavior

Accelerator opening: output torque of approximately 0.5/8

JSDIA1345GB

PCIA0008E