2008 INFINITI FX35 lock

AT-8
< SERVICE INFORMATION >
PRECAUTIONS
After performing each TROUBLE DIAGNOSIS, perform “DTC
(Diagnostic Trouble Code) Confirmation Procedure”.
If the repair is completed the DTC should not be displayed in
the “DTC Confirmation Procedure”.
 Always use the specified brand of ATF. Refer to MA-9, "
Fluids and Lubricants".
 Use lint-free paper not cloth rags during work.
 After replacing the ATF, dispose of the waste oil using the methods prescribed by law, ordinance, etc.
 Before proceeding with disassembly, thoroughly clean the out side of the transmission. It is important to pre-
vent the internal parts from becoming cont aminated by dirt or other foreign matter.
 Disassembly should be done in a clean work area.
 Use lint-free paper or towels for wiping parts clean. Common shop rags can leave fibers that could interfere
with the operation of the transmission.
 Place disassembled parts in order for easier and proper assembly.
 All parts should be carefully cleansed with a general purpose, non-flammable solvent before inspection or
reassembly.
 Gaskets, seals and O-rings should be replaced any time the transmission is disassembled.
 It is very important to perform functional tests whenever they are indicated.
 The valve body contains precision parts and requires extreme care when parts are removed and serviced. Place disassembled valve body parts in order for easier and proper assembly. Care will also prevent springs
and small parts from becoming scattered or lost.
 Properly installed valves, sleeves, plugs, etc. will s lide along bores in valve body under their own weight.
 Before assembly, apply a coat of recommended ATF to all parts. Apply petroleum jelly to protect O-rings and
seals, or hold bearings and washers in place during assembly. Do not use grease.
 Extreme care should be taken to avoid damage to O-rings, seals and gaskets when assembling.
 After overhaul, refill the transmission with new ATF.
 When the A/T drain plug is removed, only some of t he ATF is drained. Old ATF will remain in torque con-
verter and ATF cooling system.
Always follow the procedures under “Changing A/T Fluid” in the AT section when changing A/T fluid. Refer to
AT- 11 , "
Changing A/T Fluid", AT- 11 , "Checking A/T Fluid".
Service Notice or PrecautionINFOID:0000000001327125
ATF COOLER SERVICE
If ATF contains frictional material (clutches, bands, etc. ), or if an A/T is repaired, overhauled, or replaced,
inspect and clean the A/T fluid cooler mounted in the radiat or or replace the radiator. Flush cooler lines using
cleaning solvent and compressed air after repair. For A/T fluid cooler cleaning procedure, refer to AT-13, "
A/T
Fluid Cooler Cleaning". For radiator replacement, refer to CO-13 (for VQ35DE), CO-40 (for VK45DE).
OBD-II SELF-DIAGNOSIS
 A/T self-diagnosis is performed by the TCM in comb ination with the ECM. The results can be read through
the blinking pattern of the A/T CHECK indicator or the malfunction indicator lamp (MIL). Refer to the table on
AT-84, "
CONSULT-III Function (TRANSMISSION)" for the indicator used to display each self-diagnostic
result.
 The self-diagnostic results indicated by the MIL ar e automatically stored in both the ECM and TCM memo-
ries.
Always perform the procedure on AT-38, "
OBD-II Diagnostic Trouble Code (DTC)" to complete the
repair and avoid unnecessary blinking of the MIL.
For details of OBD-II, refer to EC-54
(for VQ35DE) or EC-632 (for VK45DE).
 Certain systems and components, especially those re lated to OBD, may use the new style slide-lock-
ing type harness connector. For descrip tion and how to disconnect, refer to PG-68
.
SEF217U
3AA93ABC3ACD3AC03ACA3AC03AC63AC53A913A773A893A873A873A8E3A773A983AC73AC93AC03AC3
3A893A873A873A8F3A773A9D3AAF3A8A3A8C3A863A9D3AAF3A8B3A8C

A/T CONTROL SYSTEMAT-29
< SERVICE INFORMATION >
DE
F
G H
I
J
K L
M A
B
AT
N
O P
TCM FunctionINFOID:0000000001327135
The function of the TCM is to:
 Receive input signals sent from various switches and sensors.
 Determine required line pressure, shifting point, lock-up operation, and engine brake operation.
 Send required output signals to the respective solenoids.
CONTROL SYSTEM OUTLINE
The automatic transmission senses vehicle operating condi tions through various sensors or signals. It always
controls the optimum shift position and reduces shifting and lock-up shocks.
1. Front brake 2. Input clutch 3. 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 gear 12. Input shaft
13. Mid internal gear 14. Front internal gear 15. Rear carrier
16. Rear sun gear 17. Mid sun gear 18. Front carrier
19. Mid carrier 20. Rear internal gear 21. Output shaft
22. Parking gear 23. Parking pawl
SCIA1519E
SENSORS (or SIGNALS)
⇒TCM
⇒ACTUATORS
PNP switch
Accelerator pedal position signal
Closed throttle position signal
Wide open throttle position signal
Engine speed signal
A/T fluid temperature sensor
Revolution sensor
Vehicle speed signal
Manual mode switch signal
Stop lamp switch signal
Turbine revolution sensor
ATF pressure switch Shift control
Line pressure control
Lock-up control
Engine brake control
Timing control
Fail-safe control
Self-diagnosis
CONSULT-III co
mmunication
line
Duet-EA control
CAN system Input clutch solenoid valve
Direct clutch solenoid valve
Front brake solenoid valve
High and low reverse clutch sole-
noid valve
Low coast brake solenoid valve
Torque converter clutch solenoid
valve
Line pressure solenoid valve
A/T CHECK indicator lamp
Starter relay
Back-up lamp relay
:

A/T CONTROL SYSTEMAT-31
< SERVICE INFORMATION >
DE
F
G H
I
J
K L
M A
B
AT
N
O P
Input/Output Signal of TCMINFOID:0000000001327137
*1: Spare for vehicle speed sensor·A/T (revolution sensor)
*2: Spare for accelerator pedal position signal
*3: If these input and output signals are different, the TCM triggers the fail-safe function.
*4: Used as a condition for starting self-diagnostics; if self-diagnostics are not started, it is judged that there is some kin d of error.
*5: Input by CAN communications
*6: Output by CAN communications
Line Pressure ControlINFOID:0000000001327138
 When an input torque signal equivalent to the engine drive force is sent from the ECM to the TCM, the TCM
controls the line pressure solenoid.
Control item Line
pressure control Vehicle
speed
control Shift
control Lock-up
control Engine
brake
control Fail-safe
function (*3) Self-diag-
nostics
function
Input Accelerator pedal position signal
(*5)XXXXXXX
Vehicle speed sensor A/T
(revolution sensor) XXXXXXX
Vehicle speed sensor MTR
(*1) (*5)X
Closed throttle position signal
(*5)X (*2) X X X X (*4)
Wide open throttle position signal
(*5)XX (*4)
Turbine revolution sensor 1 X X X X X
Turbine revolution sensor 2
(for 4th speed only) XXXXX
Engine speed signals
(*5)XXXXXXX
Stop lamp switch signal
(*5)XXX X (*4)
A/T fluid temperature sensors 1, 2 X X X X X X
ASCD or
ICC Operation signal
(*5)XXX
Overdrive cancel sig-
nal
(*5)X
Out-
put Direct clutch solenoid X X X X
Input clutch solenoid X X X X
High and low reverse clutch sole-
noid
XX XX
Front brake solenoid X X X X
Low coast brake solenoid (ATF
pressure switch 2) XX XXX
Line pressure solenoid X X X X X X X
TCC solenoid X X X
Self-diagnostics table
(*6)X
Starter relay XX
3AA93ABC3ACD3AC03ACA3AC03AC63AC53A913A773A893A873A873A8E3A773A983AC73AC93AC03AC3
3A893A873A873A8F3A773A9D3AAF3A8A3A8C3A863A9D3AAF3A8B3A8C

AT-34
< 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.
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 at “D” position.
- When downshifting under the manual mode.
 TCM selects “BLIPPING CONTROL” or “NORMAL SHIFT CONTROL” according to the gear position, the
select lever position, the engine torque and the speed when accelerating by accelerator pedal depression.
 Revolution control demand signal is transmitted from TCM to ECM under “BLIPPING CONTROL”.
 TCM synchronizes engine revolution according to the revolution control demand signal.
Shift Change System Diagram
Lock-up ControlINFOID:0000000001327140
The torque converter clutch piston in the torque conv erter is engaged to eliminate torque converter slip to
increase power transmission efficiency.
The torque converter clutch control valve operation is c ontrolled by the torque converter clutch solenoid valve,
which is controlled by a signal from TCM, and the to rque converter clutch control valve engages or releases
the torque converter clutch piston.
PCIA0013E
SCIA6483E
3AA93ABC3ACD3AC03ACA3AC03AC63AC53A913A773A893A873A873A8E3A773A983AC73AC93AC03AC3
3A893A873A873A8F3A773A9D3AAF3A8A3A8C3A863A9D3AAF3A8B3A8C

A/T CONTROL SYSTEMAT-35
< SERVICE INFORMATION >
DE
F
G H
I
J
K L
M A
B
AT
N
O P
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
When shifting from the lock-up released state to the lock- up applied state, the current output to the torque con-
verter clutch solenoid is controlled with the TCM. In this way, when shifting to the lock-up applied state, the
torque converter clutch is temporarily set to the half-clutched state to reduce the shock.
Half-clutched State
The current output from the TCM to the torque converte r clutch solenoid is varied to gradually increase the
torque converter clutch solenoid pressure.
In this way, the lock-up apply pressure gradually rises and while the torque converter clutch piston is put into
half-clutched status, the torque converter clutch pi ston operating pressure is increased and the coupling is
completed smoothly.
Slip Lock-up Control
In the slip region, the torque converter clutch solenoid cu rrent is controlled with the TCM to put it into the half-
clutched state. This absorbs the engine torque fluctuation and lock-up operates from low speed.
Engine Brake ControlINFOID:0000000001327141
 The forward one-way clutch transmits the drive force from the engine to the rear wheels. But the reverse
drive from the rear wheels is not transmitted to the engine because the one-way clutch is idling.
selector lever D position M5 position M4 position M3 position
Gear position 54543
Lock-up ×– ×××
Slip lock-up ××–––
PCIA0014E
3AA93ABC3ACD3AC03ACA3AC03AC63AC53A913A773A893A873A873A8E3A773A983AC73AC93AC03AC3
3A893A873A873A8F3A773A9D3AAF3A8A3A8C3A863A9D3AAF3A8B3A8C

AT-36
< SERVICE INFORMATION >
A/T CONTROL SYSTEM
Therefore, the low coast brake solenoid is operated to prevent the forward one-way clutch from idling and
the engine brake is operated in the same manner as conventionally.
 The operation of the low coast brake solenoid switches the low coast brake switching valve and controls the
coupling and releasing of the low coast brake.
The low coast brake reducing valve contro ls the low coast brake coupling force.
Control ValveINFOID:0000000001327142
FUNCTION OF CONTROL VALVE
SCIA1520E
Name Function
Torque converter regulator valve In order to prevent the pressure supplied to the torque converter from being excessive,
the line pressure is adjusted to the optimum pressure (torque converter operating pres-
sure).
Pressure regu lator valve
Pressure regulator plug
Pressure regu lator sleeve Adjusts the oil discharged from the oil pump to the optimum pressure (line pressure) for
the driving state.
Front brake control valve When the front brake is coupled, adjusts the line pressure to the optimum pressure (front
brake pressure) and supplies it to the front brake. (In 1st, 2nd, 3rd, and 5th gears, adjusts
the clutch pressure.)
Accumulator control valve Adjusts the pressure (accumulator control pressure) acting on the accumulator piston
and low coast reducing valve to the pressure appropriate to the driving state.
Pilot valve A Adjusts the line pressure and produces the constant pressure (pilot pressure) required
for line pressure control, shift change control, and lock-up control.
Pilot valve B Adjusts the line pressure and produces the constant pressure (pilot pressure) required
for shift change control.
Low coast brake switching valve During engine braking, supplies the line pressure to the low coast brake reducing valve.
Low coast brake reducing valve When the low coast brake is coupled, adjusts the line pressure to the optimum pressure
(low coast brake pressure) and supplies it to the low coast brake.
N-R accumulator Produces the stabilizing pressure for when N-R is selected.
Direct clutch piston switching valve Operates in 4th ge ar and switches the direct clutch coupling capacity.
High and low reverse clutch control valve When the high and low reverse clutch is coupled, adjusts the line pressure to the opti-
mum pressure (high and low reverse clutch pressure) and supplies it to the high and low
reverse clutch. (In 1st, 3rd, 4th and 5th gears, adjusts the clutch pressure.)
Input clutch control valve When the input clutch is coupled, adjusts the line pressure to the optimum pressure (in-
put clutch pressure) and supplies it to the input clutch. (In 4th and 5th gears, adjusts the
clutch pressure.)
Direct clutch control valve When the direct clutch is coupled, adjusts the line pressure to the optimum pressure (di-
rect clutch pressure) and supplies it to the direct clutch. (In 2nd, 3rd, and 4th gears, ad-
justs the clutch pressure.)
3AA93ABC3ACD3AC03ACA3AC03AC63AC53A913A773A893A873A873A8E3A773A983AC73AC93AC03AC3
3A893A873A873A8F3A773A9D3AAF3A8A3A8C3A863A9D3AAF3A8B3A8C

A/T CONTROL SYSTEMAT-37
< SERVICE INFORMATION >
DE
F
G H
I
J
K L
M A
B
AT
N
O P
FUNCTION OF ATF PRESSURE SWITCH
TCC control valve
TCC control plug
TCC control sleeve Switches the lock-up to operating or released. Also, by performing the lock-up operation
transiently, lock-up smoothly.
Torque converter lubrication valve Operates during lock-up to switch the torque converter, cooling, and lubrication system
oil passage.
Cool bypass valve Allows excess oil to bypass cooler circuit without being fed into it.
Line pressure relief valve Discharges excess oil from line pressure circuit.
N-D accumulator Produces the stabilizing pressure for when N-D is selected.
Manual valve Sends line pressure to each circuit according to the select position. The circuits to which
the line pressure is not sent drain.
Name Function
Name Function
ATF pressure switch 2 (LC/B) Detects any malfunction in the low coast brake hydraulic pressure. When it detects any
malfunction, it puts the system into fail-safe mode.
3AA93ABC3ACD3AC03ACA3AC03AC63AC53A913A773A893A873A873A8E3A773A983AC73AC93AC03AC3
3A893A873A873A8F3A773A9D3AAF3A8A3A8C3A863A9D3AAF3A8B3A8C

TROUBLE DIAGNOSISAT-41
< SERVICE INFORMATION >
DE
F
G H
I
J
K L
M A
B
AT
N
O P
TROUBLE DIAGNOSIS
DTC Inspection Priority ChartINFOID:0000000001327148
If some DTCs are displayed at the same time, per form inspections one by one based on the following priority
chart.
NOTE:
If “DTC U1000” is displayed with other DTCs, fi rst perform the trouble diagnosis for “DTC U1000 CAN
COMMUNICATION”. Refer to AT- 9 4
.
Fail-SafeINFOID:0000000001327149
The TCM has an electrical fail-safe mode. This mode make s it possible to operate even if there is an error in a
main electronic control input/output signal circuit.
In fail-safe mode, even if the selector lever is “D” or “M” mode, the transmission is fixed in 2nd, 4th or 5th
(depending on the breakdown position), so the customer should feel “slipping” or “poor acceleration”.
Even when the electronic circuits are normal, under s pecial conditions (for example, when slamming on the
brake with the wheels spinning drastically and stopping the ti re rotation), the transmission can go into fail-safe
mode. If this happens, switch OFF the ignition switch for 10 seconds, then switch it ON again to return to the
normal shift pattern. Therefore, t he customer's vehicle has returned to normal, so handle according to the
“WORK FLOW” (Refer to AT- 4 2
).
FAIL-SAFE FUNCTION
If any malfunction occurs in a sensor or solenoid, th is function controls the A/T to mark driving possible.
Vehicle Speed Sensor
Signals are input from two systems - from vehicle speed sensor A/T (revolution sensor) installed on the trans-
mission and from combination meter so normal driving is possible even if there is a malfunction in one of the
systems. And if vehicle speed sens or A/T (revolution sensor) has unus ual cases, 5th gear and manual mode
are prohibited.
Accelerator Pedal Position Sensor
If there is a malfunction in one of the systems, the accelerator opening angle is controlled by ECM according
to a pre-determined accelerator angle to make driving po ssible. And if there are malfunctions in tow systems,
the engine speed is fixed by ECM to a pre-determined engine speed to make driving possible.
Throttle Position Sensor
If there is a malfunction in one of the systems, the accelerator opening angle is controlled by ECM according
to a pre-determined accelerator angle to make driving po ssible. And if there are malfunctions in tow systems,
the accelerator opening angle is controlled by the idle signal sent from the ECM which is based on input indi-
cating either idle condition or off-idle condition (pre- determined accelerator opening) in order to make driving
possible.
PNP Switch
In the unlikely event that a malfunction signal enters t he TCM, the position indicator is switched OFF, the
starter relay is switched OFF (starter starting is di sabled), the back-up lamp relay switched OFF (back-up lamp
is OFF) and the position is fixed to the “D” position to make driving possible.
Starter Relay
The starter relay is switched OFF. (Starter starting is disabled.)
A/T Interlock
 If there is an A/T interlock judgment malfunction, t he A/T is fixed in 2nd gear to make driving possible.
NOTE:
When the vehicle is driven fixed in 2nd gear, a turbine revolution sensor malfunction is displayed,
but this is not a turbine r evolution sensor malfunction.
 When the coupling pattern below is detected, the fail- safe action corresponding to the pattern is performed.
A/T 1st Engine Braking
Priority Detected items (DTC)
1 U1000 CAN communication line
2 Except above
3AA93ABC3ACD3AC03ACA3AC03AC63AC53A913A773A893A873A873A8E3A773A983AC73AC93AC03AC3
3A893A873A873A8F3A773A9D3AAF3A8A3A8C3A863A9D3AAF3A8B3A8C