2005 NISSAN NAVARA engine control

A/T CONTROL SYSTEM
AT-27
D
E
F
G
H
I
J
K
L
MA
B
AT
TCM FunctionECS00FWI
The function of the TCM is to:
lReceive input signals sent from various switches and sensors.
lDetermine required line pressure, shifting point, lock-up operation, and engine brake operation.
lSend required output signals to the respective solenoids.
CONTROL SYSTEM OUTLINE
The A/T senses vehicle operating conditions through various sensors or signals. It always controls the opti-
mum shift position and reduces shifting and lock-up shocks.
CONTROL SYSTEM DIAGRAM
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
1st position switch signal
Overdrive control switch signal
Stop lamp switch signal
Turbine revolution sensor
ATF pressure switchShift control
Line pressure control
Lock-up control
Engine brake control
Timing control
Fail-safe control
Self-diagnosis
CONSULT-II communication line
Duet-EA control
CAN systemInput clutch solenoid valve
Direct clutch solenoid valve
Front brake solenoid valve
High and low reverse clutch solenoid
valve
Low coast brake solenoid valve
Torque converter clutch solenoid valve
Line pressure solenoid valve
OD OFF indicator lamp
Starter relay
Back-up lamp relay
SCIA7332E

AT-28
A/T CONTROL SYSTEM
CAN Communication
ECS00FWJ
SYSTEM DESCRIPTION
CAN (Controller Area Network) is a serial communication line for real time application. It is an on-vehicle mul-
tiplex communication line with high data communication speed and excellent error detection ability. Many elec-
tronic control units are equipped onto a vehicle, and each control unit shares information and links with other
control units during operation (not independent). In CAN communication, control units are connected with 2
communication lines (CAN H line, CAN L line) allowing a high rate of information transmission with less wiring.
Each control unit transmits/receives data but selectively reads required data only. For details, refer toLAN-30,
"CAN Communication Unit".
Input/Output Signal of TCMECS00FWK
*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-diagnosis; if self-diagnosis are not started, it is judged that there is some kind of error.
*5: Input by CAN communications.
*6: Output by CAN communications.Control itemLine
pressure
controlVehicle
speed
controlShift
controlLock-up
controlEngine
brake
controlFail-safe
function
(*3)Self-diag-
nostics
function
InputAccelerator pedal position signal
(*5)XXXXXX X
Vehicle speed sensor A/T
(revolution sensor)XXXXXX X
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)XXXXXX X
Stop lamp switch signal
(*5)XXX X(*4)
A/T fluid temperature sensors 1, 2 X X X X X X
ASCDOperation signal
(*5)XXX
Overdrive cancel signal
(*5)X
OutputDirect clutch solenoid
(ATF pressure switch 5)XX X X
Input clutch solenoid
(ATF pressure switch 3)XX X X
High and low reverse clutch solenoid
(ATF pressure switch 6)XX X X
Front brake solenoid
(ATF pressure switch 1)XX X X
Low coast brake solenoid
(ATF pressure switch 2)XX XX X
Line pressure solenoid X X X X X X X
TCC solenoid X X X
Self-diagnosis table
(*6)X
Starter relayXX

A/T CONTROL SYSTEM
AT-29
D
E
F
G
H
I
J
K
L
MA
B
AT
Line Pressure ControlECS00FWL
lWhen 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.
lThis line pressure solenoid controls the pressure regulator valve as the signal pressure and adjusts the
pressure of the operating oil discharged from the oil pump to the line pressure most appropriate to the
driving state.
LINE PRESSURE CONTROL IS BASED ON THE TCM LINE PRESSURE CHARACTERISTIC
PAT T E R N
lThe TCM has stored in memory a number of patterns for the optimum line pressure characteristic for the
driving state.
lIn 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)
When the select operation is performed during driving and the A/T is
shifted down, the line pressure is set according to the vehicle speed.
PCIA0007E
PCIA0008E
PCIA0009E

AT-30
A/T CONTROL SYSTEM
During Shift Change
The necessary and adequate line pressure for shift change is set.
For this reason, line pressure pattern setting corresponds to input
torque and gearshift selection. Also, line pressure characteristic is
set according to engine speed, during engine brake operation.
At Low Fluid Temperature
When the A/T fluid temperature drops below the prescribed tempera-
ture, in order to speed up the action of each friction element, the line
pressure is set higher than the normal line pressure characteristic.
Shift ControlECS00FWM
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 the engine load state and vehicle driving state. It becomes
possible to finely control the clutch hydraulic pressure with high precision and a smoother shift change charac-
teristic is attained.
PCIA0010E
PCIA0011E
PCIA0012E

A/T CONTROL SYSTEM
AT-31
D
E
F
G
H
I
J
K
L
MA
B
AT
SHIFT CHANGE
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 movement of gear ratio at gear change, and controls oil
pressure at real-time to achieve the best gear ratio.
Lock-up ControlECS00FWN
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.
PCIA0013E
selector lever “D” position “3” position “2” position
Gear position 5 4 3 2
Lock-up´–´´
PCIA0014E

AT-32
A/T CONTROL SYSTEM
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 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 piston operating pressure is increased and the coupling is
completed smoothly.
Engine Brake ControlECS00FWO
lThe 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.
lThe 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.
SCIA1520E

A/T CONTROL SYSTEM
AT-33
D
E
F
G
H
I
J
K
L
MA
B
AT
Control ValveECS00FWP
FUNCTION OF CONTROL VALVE
FUNCTION OF PRESSURE SWITCH
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 pressure).
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
theclutchpressure.)
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 optimum
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 valveWhen the input clutch is coupled, adjusts the line pressure to the optimum pressure (input
clutch pressure) and supplies it to the input clutch. (In 4th and 5th gears, adjusts the clutch
pressure.)
Direct clutch control valveWhen the direct clutch is coupled, adjusts the line pressure to the optimum pressure
(direct clutch pressure) and supplies it to the direct clutch. (In 2nd, 3rd, and 4th gears,
adjusts the clutch pressure.)
TCC control valve
TCC control plug
TCC control sleeveSwitches the lock-up to operating or released. Also, by performing the lock-up operation
transiently, lock-up smoothly.
Torque converter lubrication valveOperates during lock-up to switch the torque converter, cooling, and lubrication system oil
path.
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 valveSends line pressure to each circuit according to the select position. The circuits to which
the line pressure is not sent drain.
Name Function
ATFpressureswitch1(FR/B)Detects any malfunction in the front brake hydraulic pressure. When it detects any malfunction,
it puts the system into fail-safe mode.
ATFpressureswitch2(LC/B)Detects any malfunction in the low coast brake hydraulic pressure. When it detects any mal-
function, it puts the system into fail-safe mode.
ATFpressureswitch3(I/C)Detects any malfunction in the input clutch hydraulic pressure. When it detects any malfunction,
it puts the system into fail-safe mode.
ATF pressure switch 5 (D/C)Detects any malfunction in the direct clutch hydraulic pressure. When it detects any malfunc-
tion, it puts the system into fail-safe mode.
ATF pressure switch 6 (HLR/C)Detects any malfunction in the high and low reverse clutch hydraulic pressure. When it detects
any malfunction, it puts the system into fail-safe mode.

AT-34
TROUBLE DIAGNOSIS
TROUBLE DIAGNOSIS
PFP:00004
DTC Inspection Priority ChartECS00FWV
If some DTCs are displayed at the same time, perform inspections one by one based on the following priority
chart.
NOTE:
If DTC “U1000 CAN COMM CIRCUIT” is displayed with other DTCs, first perform the trouble diagnosis
for “DTC U1000 CAN COMMUNICATION LINE”. Refer toAT-91
.
Fail-safeECS00FWW
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 A/T 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 special conditions (for example, when slamming on the
brake with the wheels spinning drastically and stopping the tire 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, the customer's vehicle has returned to normal, so handle according toAT- 3 7 ,
"WORK FLOW".
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 is 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 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.
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