2006 INFINITI M35 Shift

AT-36
A/T CONTROL SYSTEM
Revision: 2006 January2006 M35/M45
Shift Change System Diagram
ASC (ADOPTIVE SHIFT CONTROL)
ASC automatically shifts or hold at the 3rd or 4th gear on certain roads (up/down slope and curve) and driving
condition.
When Driving on an Up/down Slope
ASC judges up/down slope according to the angle of accelerator pedal and vehicle speed. Holding gear at
the 3rd or 4th on an up-slope prevents shift hunting and controls the vehicle to gain maximum driving
force. On a down-slope, automatic shift-down to the 3rd or 4th gear controls to gain maximum engine
brake.
When Driving on a Curve
TCM receives side G sensor signal from ABS actuator and electric unit (control unit). Holding gear at the
3rd or 4th based on the signal prevents shift-up and kick-down and controls to drive smoothly.
SCIA6483E
SCIA6469E

A/T CONTROL SYSTEM
AT-37
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Revision: 2006 January2006 M35/M45
Lock-up ControlNCS001JU
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
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 converter clutch solenoid is varied to steadily 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 piston operating pressure is increased and the cou-
pling is completed smoothly.
Slip Lock-up Control
In the slip region, the torque converter clutch solenoid current 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.
This raises the fuel efficiency for 3rd, 4th and 5th gears at both low speed and when the accelerator has a
low degree of opening.
Selector lever “D” position “M” position
Gear position 5 4 3 5 4
Lock-up
––
Slip lock-up––
PCIA0014E

AT-38
A/T CONTROL SYSTEM
Revision: 2006 January2006 M35/M45
Engine Brake ControlNCS001JV
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.
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 controls the low coast brake coupling force.
Control ValveNCS001JW
FUNCTION OF CONTROL VALVE
SCIA1520E
Name Function
Torque converter regulator valveIn 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 regulator valve
Pressure regulator plug
Pressure regulator sleeveAdjusts the oil discharged from the oil pump to the optimum pressure (line pressure) for
the driving state.
Front brake control valveWhen 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 valveAdjusts 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 AAdjusts the line pressure and produces the constant pressure (pilot pressure) required
for line pressure control, shift change control, and lock-up control.
Pilot valve BAdjusts 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 valveWhen 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 gear and switches the direct clutch coupling capacity.
High and low reverse clutch control valveWhen 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.)

AT-44
TROUBLE DIAGNOSIS
Revision: 2006 January2006 M35/M45
TROUBLE DIAGNOSISPFP:00004
DTC Inspection Priority ChartNCS001K2
If some DTCs are displayed at the same time, perform inspections one by one based on the following priority
chart.
NOTE:
If DTC “U1000” is displayed with other DTC, first perform the trouble diagnosis for “DTC U1000 CAN
COMMUNICATION LINE”. Refer to AT- 1 0 5
.
Fail-safeNCS001K3
The TCM has an electrical fail-safe mode. This mode makes 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 A/T is fixed in 2nd, 4th and 5th (depending
on the breakdown position), so the customer should feel “slipping” or “poor acceleration”.
Even when the electronic circuits are normal, under special conditions (for example, when slamming on the
brake with the wheels spinning drastically and stopping the tire rotation), the A/T 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, the customer's vehicle has returned to normal, so handle according to the “WORK
FLOW” (Refer to AT- 4 7
).
FAIL-SAFE FUNCTION
If any malfunction occurs in a sensor or solenoid, this 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 A/
T and from combination meter so normal driving is possible even if there is a malfunction in one of the
systems. And if vehicle speed sensor A/T (revolution sensor) has unusual 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 accord-
ing to a pre-determined accelerator angle to make driving possible. 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 accord-
ing to a pre-determined accelerator angle to make driving possible. 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 indicating 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 the TCM, the position indicator is switched OFF, the
starter relay is switched OFF (starter starting is disabled), 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.)
Priority Detected items (DTC)
1 U1000 CAN communication line
2 Except above

AT-46
TROUBLE DIAGNOSIS
Revision: 2006 January2006 M35/M45
How to Perform Trouble Diagnosis for Quick and Accurate RepairNCS001K4
INTRODUCTION
The TCM receives a signal from the vehicle speed sensor, accelera-
tor pedal position sensor (throttle position sensor) or PNP switch and
provides shift control or lock-up control via A/T solenoid valves.
The TCM also communicates with the ECM by means of a signal
sent from sensing elements used with the OBD-related parts of the
A/T system for malfunction-diagnostic purposes. The TCM is capa-
ble of diagnosing malfunctioning parts while the ECM can store mal-
functions in its memory.
Input and output signals must always be correct and stable in the
operation of the A/T system. The A/T system must be in good oper-
ating condition and be free of valve seizure, solenoid valve malfunc-
tion, etc.
It is much more difficult to diagnose a error that occurs intermittently
rather than continuously. Most intermittent errors are caused by poor
electric connections or improper wiring. In this case, careful check-
ing of suspected circuits may help prevent the replacement of good
parts.
A visual check only may not find the cause of the errors. A road test
with CONSULT-II (or GST) or a circuit tester connected should be
performed. Follow the AT- 4 7 , "
WORK FLOW" .
Before undertaking actual checks, take a few minutes to talk with a
customer who approaches with a driveability complaint. The cus-
tomer can supply good information about such errors, especially
intermittent ones. Find out what symptoms are present and under
what conditions they occur. A “DIAGNOSTIC WORKSHEET” as
shown on the example (Refer to AT- 4 8
) should be used.
Start your diagnosis by looking for “conventional” errors first. This will
help troubleshoot driveability errors on an electronically controlled
engine vehicle.
Also check related Service bulletins.
SAT631IB
SAT632I
SEF234G

AT-48
TROUBLE DIAGNOSIS
Revision: 2006 January2006 M35/M45
DIAGNOSTIC WORKSHEET
Information from Customer
KEY POINTS
WHAT..... Vehicle and A/T model
WHEN..... Date, Frequencies
WHERE..... Road conditions
HOW..... Operating conditions, Symptoms
Diagnostic Worksheet Chart
Customer name MR/MS Model and Year VIN
Trans. Model Engine Mileage
Malfunction Date Manuf. Date In Service Date
Frequency
Continuous Intermittent ( times a day)
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 complaint.AT- 4 4
2
A/T fluid inspectionAT- 5 3
Leak (Repair leak location.)
State
Amount
3
Stall test and line pressure testAT- 5 3, AT-
55 Stall test
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 inspection - Suspected part:

TROUBLE DIAGNOSIS
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Revision: 2006 January2006 M35/M45
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Perform all road tests and enter checks in required inspection items.AT- 5 7
4-1.Check before engine is started AT- 5 7
AT- 1 9 0 , "A/T CHECK Indicator Lamp Does Not Come On"
Perform self-diagnostics. Enter checks for detected items. AT- 9 2 ,AT-103
AT-105, "DTC U1000 CAN COMMUNICATION LINE"
AT-108, "DTC P0615 START SIGNAL CIRCUIT"
AT-112, "DTC P0700 TCM"
AT-113, "DTC P0705 PARK/NEUTRAL POSITION SWITCH"
AT-117, "DTC P0717 TURBINE REVOLUTION SENSOR"
AT-119, "DTC P0720 VEHICLE SPEED SENSOR A/T (REVOLUTION SENSOR)"
AT-124, "DTC P0725 ENGINE SPEED SIGNAL"
AT-126, "DTC P0740 TORQUE CONVERTER CLUTCH SOLENOID VALVE"
AT-128, "DTC P0744 A/T TCC S/V FUNCTION (LOCK-UP)"
AT-130, "DTC P0745 LINE PRESSURE SOLENOID VALVE"
AT-132, "DTC P1705 THROTTLE POSITION SENSOR"
AT-135, "DTC P1710 A/T FLUID TEMPERATURE SENSOR CIRCUIT"
AT-140, "DTC P1721 VEHICLE SPEED SENSOR MTR"
AT-142, "DTC P1730 A/T INTERLOCK"
AT-145, "DTC P1731 A/T 1ST ENGINE BRAKING"
AT-147, "DTC P1752 INPUT CLUTCH SOLENOID VALVE"
AT-149, "DTC P1754 INPUT CLUTCH SOLENOID VALVE FUNCTION"
AT-151, "DTC P1757 FRONT BRAKE SOLENOID VALVE"
AT-153, "DTC P1759 FRONT BRAKE SOLENOID VALVE FUNCTION"
AT-155, "DTC P1762 DIRECT CLUTCH SOLENOID VALVE"
AT-157, "DTC P1764 DIRECT CLUTCH SOLENOID VALVE FUNCTION"
AT-159, "DTC P1767 HIGH AND LOW REVERSE CLUTCH SOLENOID VALVE"
AT-161, "DTC P1769 HIGH AND LOW REVERSE CLUTCH SOLENOID VALVE
FUNCTION"
AT-163, "DTC P1772 LOW COAST BRAKE SOLENOID VALVE"
AT-165, "DTC P1774 LOW COAST BRAKE SOLENOID VALVE FUNCTION"
AT-167, "DTC P1815 MANUAL MODE SWITCH"
AT-172, "DTC P1841 ATF PRESSURE SWITCH 1"
AT-174, "DTC P1843 ATF PRESSURE SWITCH 3"
AT-176, "DTC P1845 ATF PRESSURE SWITCH 5"
AT-178, "DTC P1846 ATF PRESSURE SWITCH 6"
4-2.Check at IdleAT- 5 7
AT- 1 9 0 , "Engine Cannot Be Started in “P” or “N” Position"
AT- 1 9 1 , "In “P” Position, Vehicle Moves When Pushed"
AT- 1 9 2 , "In “N” Position, Vehicle Moves"
AT- 1 9 3 , "Large Shock (“N” to “D” Position)"
AT- 1 9 5 , "Vehicle Does Not Creep Backward in “R” Position"
AT- 1 9 7 , "Vehicle Does Not Creep Forward in “D” Position"
4-3.Cruise TestAT- 5 9
Part 1
AT- 1 9 9 , "Vehicle Cannot Be Started from D1"
AT- 2 0 1 , "A/T Does Not Shift: D1 D2"
AT- 2 0 3 , "A/T Does Not Shift: D2 D3"
AT- 2 0 5 , "A/T Does Not Shift: D3 D4"
AT- 2 0 7 , "A/T Does Not Shift: D4 D5"
AT- 2 0 9 , "A/T Does Not Lock-Up"
AT- 2 1 0 , "A/T Does Not Hold Lock-Up Condition"
AT- 2 1 2 , "Lock-Up Is Not Released"
AT- 2 1 2 , "Engine Speed Does Not Return to Idle"

AT-50
TROUBLE DIAGNOSIS
Revision: 2006 January2006 M35/M45
44-3Part 2AT- 6 1
AT-199, "Vehicle Cannot Be Started from D1"
AT-201, "A/T Does Not Shift: D1 D2"
AT-203, "A/T Does Not Shift: D2 D3"
AT-205, "A/T Does Not Shift: D3 D4"
Part 3AT- 6 2
AT-213, "Cannot Be Changed to Manual Mode"
AT-214, "A/T Does Not Shift: 5th Gear 4th Gear"
AT-215, "A/T Does Not Shift: 4th Gear 3rd Gear"
AT-217, "A/T Does Not Shift: 3rd Gear 2nd Gear"
AT-218, "A/T Does Not Shift: 2nd Gear 1st Gear"
AT-220, "Vehicle Does Not Decelerate by Engine Brake"
Perform self-diagnostics. Enter checks for detected items. AT- 9 2 , AT-103
AT-105, "DTC U1000 CAN COMMUNICATION LINE"
AT-108, "DTC P0615 START SIGNAL CIRCUIT"
AT- 11 2 , "DTC P0700 TCM"
AT- 11 3 , "DTC P0705 PARK/NEUTRAL POSITION SWITCH"
AT- 11 7 , "DTC P0717 TURBINE REVOLUTION SENSOR"
AT- 11 9 , "DTC P0720 VEHICLE SPEED SENSOR A/T (REVOLUTION SENSOR)"
AT-124, "DTC P0725 ENGINE SPEED SIGNAL"
AT-126, "DTC P0740 TORQUE CONVERTER CLUTCH SOLENOID VALVE"
AT-128, "DTC P0744 A/T TCC S/V FUNCTION (LOCK-UP)"
AT-130, "DTC P0745 LINE PRESSURE SOLENOID VALVE"
AT-132, "DTC P1705 THROTTLE POSITION SENSOR"
AT-135, "DTC P1710 A/T FLUID TEMPERATURE SENSOR CIRCUIT"
AT-140, "DTC P1721 VEHICLE SPEED SENSOR MTR"
AT-142, "DTC P1730 A/T INTERLOCK"
AT-145, "DTC P1731 A/T 1ST ENGINE BRAKING"
AT-147, "DTC P1752 INPUT CLUTCH SOLENOID VALVE"
AT-149, "DTC P1754 INPUT CLUTCH SOLENOID VALVE FUNCTION"
AT-151, "DTC P1757 FRONT BRAKE SOLENOID VALVE"
AT-153, "DTC P1759 FRONT BRAKE SOLENOID VALVE FUNCTION"
AT-155, "DTC P1762 DIRECT CLUTCH SOLENOID VALVE"
AT-157, "DTC P1764 DIRECT CLUTCH SOLENOID VALVE FUNCTION"
AT-159, "DTC P1767 HIGH AND LOW REVERSE CLUTCH SOLENOID VALVE"
AT-161, "DTC P1769 HIGH AND LOW REVERSE CLUTCH SOLENOID VALVE
FUNCTION"
AT-163, "DTC P1772 LOW COAST BRAKE SOLENOID VALVE"
AT-165, "DTC P1774 LOW COAST BRAKE SOLENOID VALVE FUNCTION"
AT-167, "DTC P1815 MANUAL MODE SWITCH"
AT-172, "DTC P1841 ATF PRESSURE SWITCH 1"
AT-174, "DTC P1843 ATF PRESSURE SWITCH 3"
AT-176, "DTC P1845 ATF PRESSURE SWITCH 5"
AT-178, "DTC P1846 ATF PRESSURE SWITCH 6"
5 Inspect each system for items found to be NG in the self-diagnostics and repair or replace the malfunctioning parts.
6
Perform all road tests and enter the checks again for the required items.AT- 5 7
7
For any remaining NG items, perform the “Diagnostics Procedure” and repair or replace the malfunctioning
parts. See the chart for diagnostics by symptoms. (This chart also contains other symptoms and inspection pro-
cedures.)AT- 6 4
8 Erase the results of the self-diagnostics from the TCM.AT- 9 6, AT-
104