2001 INFINITI QX4 brake sensor

19. A/T Does Not Shift: 22-> 11, When Selector
Lever²2²->²1²Position .........................................255
20. Vehicle Does Not Decelerate By Engine
Brake........................................................................256
21. TCM Self-diagnosis Does Not Activate (PNP,
Overdrive Control and Throttle Position Switches
Circuit Checks) ........................................................257
A/T SHIFT LOCK SYSTEM.........................................265
Description ...............................................................265
Wiring Diagram - SHIFT -........................................266
Diagnostic Procedure ..............................................267
KEY INTERLOCK CABLE..........................................271
Components.............................................................271
Removal ...................................................................271
Installation ................................................................272
ON-VEHICLE SERVICE..............................................273
Control Valve Assembly and Accumulators .............273
Revolution Sensor Replacement .............................274
Turbine Revolution Sensor Replacement................274
Rear Oil Seal Replacement .....................................274
Rear Oil Seal and Companion Flange Oil Seal
Replacement ............................................................275
Parking Components Inspection..............................275
Park/Neutral Position Switch Adjustment ................276
Manual Control Linkage Adjustment........................276
REMOVAL AND INSTALLATION...............................277
Removal ...................................................................277
Installation ................................................................278
OVERHAUL.................................................................281
Components.............................................................281
Oil Channel ..............................................................284
Locations of Needle Bearings, Thrust Washers
and Snap Rings .......................................................285
DISASSEMBLY............................................................286
REPAIR FOR COMPONENT PARTS.........................297Oil Pump ..................................................................297
Control Valve Assembly ...........................................301
Control Valve Upper Body .......................................307
Control Valve Lower Body .......................................312
Reverse Clutch ........................................................314
High Clutch ..............................................................317
Forward and Overrun Clutches ...............................320
Low & Reverse Brake..............................................324
Forward Clutch Drum Assembly ..............................328
Rear Internal Gear and Forward Clutch Hub ..........330
Band Servo Piston Assembly ..................................333
Parking Pawl Components ......................................337
ASSEMBLY..................................................................339
Assembly (1) ............................................................339
Adjustment ...............................................................347
Assembly (2) ............................................................349
SERVICE DATA AND SPECIFICATIONS (SDS).......356
General Specifications .............................................356
Shift Schedule..........................................................356
Stall Revolution ........................................................356
Line Pressure...........................................................356
Return Springs .........................................................357
Accumulator O-ring ..................................................358
Clutches and Brakes ...............................................358
Oil Pump and Low One-way Clutch ........................360
Total End Play..........................................................360
Reverse Clutch Drum End Play ..............................361
Removal and Installation .........................................361
Shift Solenoid Valves ...............................................361
Solenoid Valves .......................................................361
A/T Fluid Temperature Sensor.................................361
Turbine Revolution Sensor ......................................361
Revolution Sensor ...................................................362
Dropping Resistor ....................................................362GI
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CONTENTS(Cont'd)
AT-3

TCM FUNCTION=NBAT0013S03The function of the TCM is to:
IReceive input signals sent from various switches and sensors.
IDetermine required line pressure, shifting point, lock-up operation, and engine brake operation.
ISend required output signals to the respective solenoids.
INPUT/OUTPUT SIGNAL OF TCMNBAT0013S04
Sensors and solenoid valves Function
InputPNP switch Detects select lever position and sends a signal to TCM.
Throttle position sensor Detects throttle valve position and sends a signal to TCM.
Closed throttle position switch Detects throttle valve's fully-closed position and sends a signal to TCM.
Wide open throttle position switchDetects a throttle valve position of greater than 1/2 of full throttle and sends
a signal to TCM.
Engine speed signal From ECM.
A/T fluid temperature sensor Detects transmission fluid temperature and sends a signal to TCM.
Revolution sensor Detects output shaft rpm and sends a signal to TCM.
Vehicle speed sensorUsed as an auxiliary vehicle speed sensor. Sends a signal when revolution
sensor (installed on transmission) malfunctions.
Overdrive control switchSends a signal, which prohibits a shift to ªD
4º (overdrive) position, to the
TCM.
ASCD control unitSends the cruise signal and ªD
4º (overdrive) cancellation signal from ASCD
control unit to TCM.
Turbine revolution sensor Sends an input shaft revolution signal.
Stop lamp switch Sends the lock-up release signal to the TCM at time of D
4(lock-up).
OutputShift solenoid valve A/BSelects shifting point suited to driving conditions in relation to a signal sent
from TCM.
Line pressure solenoid valveRegulates (or decreases) line pressure suited to driving conditions in rela-
tion to a signal sent from TCM.
Torque converter clutch solenoid
valveRegulates (or decreases) lock-up pressure suited to driving conditions in
relation to a signal sent from TCM.
Overrun clutch solenoid valveControls an ªengine brakeº effect suited to driving conditions in relation to a
signal sent from TCM.
O/D OFF indicator lamp Shows TCM faults, when A/T control components malfunction.
Control MechanismNBAT0180LINE PRESSURE CONTROLNBAT0180S01TCM has the various line pressure control characteristics to meet
the driving conditions.
An ON-OFF duty signal is sent to the line pressure solenoid valve
based on TCM characteristics.
Hydraulic pressure on the clutch and brake is electronically con-
trolled through the line pressure solenoid valve to accommodate
engine torque. This results in smooth shift operation.
OVERALL SYSTEM
Control System (Cont'd)
AT-26

SAT007J
ILine pressure is increased to a maximum irrespective of the
throttle opening when fluid temperature drops to þ10ÉC (14ÉF).
This pressure rise is adopted to prevent a delay in clutch and
brake operation due to extreme drop of fluid viscosity at low
temperature.
SHIFT CONTROLNBAT0180S02The shift is regulated entirely by electronic control to accommodate
vehicle speed and varying engine operations. This is accomplished
by electrical signals transmitted by the revolution sensor and
throttle position sensor. This results in improved acceleration per-
formance and fuel economy.
SAT008J
Control of Shift Solenoid Valves A and BNBAT0180S0201The TCM activates shift solenoid valves A and B according to sig-
nals from the throttle position sensor and revolution sensor to
select the optimum gear position on the basis of the shift schedule
memorized in the TCM.
The shift solenoid valve performs simple ON-OFF operation. When
set to ªONº, the drain circuit closes and pilot pressure is applied to
the shift valve.
[Relation between shift solenoid valves A and B and gear positions]
Shift solenoid valveGear position
D
1,21,11D2,22,12D3D4(OD) N-P
A ON (Closed) OFF (Open) OFF (Open) ON (Closed) ON (Closed)
B ON (Closed) ON (Closed) OFF (Open) OFF (Open) ON (Closed)
Control of Shift Valves A and BNBAT0180S0202
SAT047J
OVERALL SYSTEM
Control Mechanism (Cont'd)
AT-28

Diagnostic Worksheet=NBAT0019S0102
1.lRead the Fail-safe Remarks and listen to customer complaints. AT-8
2.lCHECK A/T FLUIDAT-59
lLeakage (Follow specified procedure)
lFluid condition
lFluid level
3. Perform STALL TEST and LINE PRESSURE TEST. AT-59, AT-62
lStall test Ð Mark possible damaged components/others.
lTorque converter one-way clutch
lReverse clutch
lForward clutch
lOverrun clutch
lForward one-way clutchlLow & reverse brake
lLow one-way clutch
lEngine
lLine pressure is low
lClutches and brakes except high clutch and
brake band are OK
lPressure test Ð Suspected parts:
4.lPerform all ROAD TEST and mark required procedures. AT-63
4-1. Check before engine is started.AT-64
lSELF-DIAGNOSTIC PROCEDURE - Mark detected items.
lDTC P0705 PNP switch, AT-99.
lDTC P0710 A/T fluid temperature sensor, AT-105.
lDTC P0720 Vehicle speed sensor´A/T (Revolution sensor), AT-111.
lDTC P0725 Engine speed signal, AT-116.
lDTC P0740 Torque converter clutch solenoid valve, AT-148.
lDTC P0745 Line pressure solenoid valve, AT-162.
lDTC P0750 Shift solenoid valve A, AT-168.
lDTC P0755 Shift solenoid valve B, AT-172.
lDTC P1705 Throttle position sensor, AT-176.
lDTC P1760 Overrun clutch solenoid valve, AT-185.
lDTC BATT/FLUID TEMP SEN (A/T fluid temperature sensor and TCM power source), AT-190.
lDTC Vehicle speed sensor´MTR, AT-197.
lDTC Turbine revolution sensor, AT-202.
lDTC A/T communication line, AT-207.
lDTC Control unit (RAM), control unit (ROM), AT-211.
lDTC Control unit (EEP ROM), AT-213.
lPNP, overdrive control and throttle position switches, AT-257.
lBattery
lOthers
4-2. Check at idleAT-66
l1. O/D OFF Indicator Lamp Does Not Come On, AT-218.
l2. Engine Cannot Be Started In ªPº And ªNº Position, AT-221.
l3. In ªPº Position, Vehicle Moves Forward Or Backward When Pushed, AT-222.
l4. In ªNº Position, Vehicle Moves, AT-223.
l5. Large Shock. ªNº,ªRº Position, AT-225.
l6. Vehicle Does Not Creep Backward In ªRº Position, AT-227.
l7. Vehicle Does Not Creep Forward In ªDº, ª2º Or ª1º Position, AT-230.GI
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TROUBLE DIAGNOSIS Ð INTRODUCTION
Introduction (Cont'd)
AT-55

4. 4-3. Cruise testAT-67
AT-71
Part-1
l8. Vehicle Cannot Be Started From D
1, AT-233.
l9. A/T Does Not Shift: D
1,D2Or Does Not Kickdown: D4,D2, AT-236.
l10. A/T Does Not Shift: D
2,D3, AT-239.
l11. A/T Does Not Shift: D
3,D4, AT-242.
l12. A/T Does Not Perform Lock-up, AT-245.
l13. A/T Does Not Hold Lock-up Condition, AT-247.
l14. Lock-up Is Not Released, AT-249.
l15. Engine Speed Does Not Return To Idle (Light Braking D
4,D3), AT-250.
Part-2AT-75
l16. Vehicle Does Not Start From D
1, AT-252.
l9. A/T Does Not Shift: D
1,D2Or Does Not Kickdown: D4,D2, AT-236.
l10. A/T Does Not Shift: D
2,D3, AT-239.
l11. A/T Does Not Shift: D
3,D4, AT-242.
Part-3AT-77
l17. A/T Does Not Shift: D
4,D3When Overdrive Control Switch ªONº,ªOFFº, AT-253
l15. Engine Speed Does Not Return To Idle (Engine Brake In D
3), AT-250.
l18. A/T Does Not Shift: D
3,22, When Selector Lever ªDº,ª2º Position, AT-254.
l15. Engine Speed Does Not Return To Idle (Engine Brake In 2
2), AT-250.
l19. A/T Does Not Shift: 2
2,11, When Selector Lever ª2º,ª1º Position, AT-255.
l20. Vehicle Does Not Decelerate By Engine Brake, AT-256.
lSELF-DIAGNOSTIC PROCEDURE Ð Mark detected items.
lDTC P0705 PNP switch, AT-99.
lDTC P0710 A/T fluid temperature sensor, AT-105.
lDTC P0720 Vehicle speed sensor´A/T (Revolution sensor), AT-111.
lDTC P0725 Engine speed signal, AT-116.
lDTC P0740 Torque converter clutch solenoid valve, AT-148.
lDTC P0745 Line pressure solenoid valve, AT-162.
lDTC P0750 Shift solenoid valve A, AT-168.
lDTC P0755 Shift solenoid valve B, AT-172.
lDTC P1705 Throttle position sensor, AT-176.
lDTC P1760 Overrun clutch solenoid valve, AT-185.
lDTC BATT/FLUID TEMP SEN (A/T fluid temperature sensor and TCM power source), AT-190.
lDTC Vehicle speed sensor´MTR, AT-197.
lDTC Turbine revolution sensor, AT-202.
lDTC A/T communication line, AT-207.
lDTC Control unit (RAM), control unit (ROM), AT-211.
lDTC Control unit (EEP ROM), AT-213.
lPNP, overdrive control and throttle position switches, AT-257.
lBattery
lOthers
5.lFor self-diagnosis NG items, inspect each component. Repair or replace the damaged parts. AT-38
6.lPerform all ROAD TEST and re-mark required procedures. AT-63
7.lPerform DTC CONFIRMATION PROCEDURE for following MIL indicating items and check out NG items.
Refer to EC-60, ªEmission-related Diagnostic Informationº.EC-60
lDTC (P0731, 1103) A/T 1st gear function, AT-120.
lDTC (P0732, 1104) A/T 2nd gear function, AT-126.
lDTC (P0733, 1105) A/T 3rd gear function, AT-132.
lDTC (P0734, 1106) A/T 4th gear function, AT-138.
lDTC (P0744, 1107) A/T TCC S/V function (lock-up), AT-153.
8.lPerform the Diagnostic Procedures for all remaining items marked NG. Repair or replace the damaged
parts.
Refer to the Symptom Chart when you perform the procedures. (The chart also shows some other possible
symptoms and the component inspection orders.)AT-92
AT-97
9.lErase DTC from TCM and ECM memories. AT-35
TROUBLE DIAGNOSIS Ð INTRODUCTION
Introduction (Cont'd)
AT-56

SAT493G
5. Start engine and measure line pressure at idle and stall speed.
IWhen measuring line pressure at stall speed, follow the
stall test procedure.
Line pressure:
Refer to SDS, AT-356.
JUDGEMENT OF LINE PRESSURE TESTNBAT0023S02
Judgement Suspected parts
At idleLine pressure is low in all posi-
tions.IOil pump wear
IControl piston damage
IPressure regulator valve or plug sticking
ISpring for pressure regulator valve damaged
IFluid pressure leakage between oil strainer and pressure regulator valve
IClogged strainer
Line pressure is low in particu-
lar position.IFluid pressure leakage between manual valve and particular clutch
IFor example, line pressure is:
Ð Low in ªRº and ª1º positions, but
Ð Normal in ªDº and ª2º positions.
Then, fluid leakage exists at or around low and reverse brake circuit.
Refer to ªCLUTCH AND BAND CHARTº, AT-17.
Line pressure is high.IMal-adjustment of throttle position sensor
IFluid temperature sensor damaged
ILine pressure solenoid valve sticking
IShort circuit of line pressure solenoid valve circuit
IPressure modifier valve sticking
IPressure regulator valve or plug sticking
IOpen in dropping resistor circuit
At stall speedLine pressure is low.IMal-adjustment of throttle position sensor
ILine pressure solenoid valve sticking
IShort circuit of line pressure solenoid valve circuit
IPressure regulator valve or plug sticking
IPressure modifier valve sticking
IPilot valve sticking
SAT786A
Road TestNBAT0024DESCRIPTIONNBAT0024S01IThe purpose of the test is to determine overall performance of
A/T and analyze causes of problems.
IThe road test consists of the following three parts:
1. Check before engine is started
2. Check at idle
3. Cruise test
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TROUBLE DIAGNOSIS Ð BASIC INSPECTION
Line Pressure Test (Cont'd)
AT-63

Items Symptom Condition Diagnostic Item Reference Page
Shift ShockToo sharp a
shock in change
from D
1to D2.ON vehicle1. Throttle position sensor (Adjustment) EC-174
2. Line pressure test AT-62
3. Accumulator servo release AT-273
4. Control valve assembly AT-273
5. A/T fluid temperature sensor AT-105
OFF vehicle 6. Brake band AT-333
Too sharp a
shock in change
from D
2to D3.ON vehicle1. Throttle position sensor (Adjustment) EC-174
2. Line pressure test AT-62
3. Control valve assembly AT-273
OFF vehicle4. High clutch AT-317
5. Brake band AT-333
Too sharp a
shock in change
from D
3to D4.ON vehicle1. Throttle position sensor (Adjustment) EC-174
2. Line pressure test AT-62
3. Control valve assembly AT-273
OFF vehicle4. Brake band AT-333
5. Overrun clutch AT-320
Gear change
shock felt during
deceleration by
releasing accel-
erator pedal.ON vehicle1. Throttle position sensor (Adjustment) EC-174
2. Line pressure test AT-62
3. Overrun clutch solenoid valve AT-185
4. Control valve assembly AT-273
Large shock
changing from 1
2to 11in 1 position.ON vehicle 1. Control valve assembly AT-273
ON vehicle 2. Low & reverse brake AT-324
Improper Shift
TimingToo high a gear
change point from
D
1to D2, from D2to D3, from D3to
D
4.
AT-236, 239, 242ON vehicle1. Throttle position sensor (Adjustment) EC-174
2. Vehicle speed sensor´A/T (Revolution
sensor) and vehicle speed sensor´MTRAT- 111 , 1 9 7
3. Shift solenoid valve A AT-168
4. Shift solenoid valve B AT-172
Gear change
directly from D
1to
D
3occurs.ON vehicle1. Fluid level AT-59
2. Accumulator servo release AT-273
OFF vehicle 3. Brake band AT-333
Too high a
change point from
D
4to D3, from D3to D2, from D2to
D
1.ON vehicle1. Throttle position sensor (Adjustment) EC-174
2. Vehicle speed sensor´A/T (Revolution
sensor) and vehicle speed sensor´MTRAT- 111 , 1 9 7
Kickdown does
not operate when
depressing pedal
in D
4within kick-
down vehicle
speed.ON vehicle1. Throttle position sensor (Adjustment) EC-174
2. Vehicle speed sensor´A/T (Revolution
sensor) and vehicle speed sensor´MTRAT- 111 , 1 9 7
3. Shift solenoid valve A AT-168
4. Shift solenoid valve B AT-172
TROUBLE DIAGNOSIS Ð GENERAL DESCRIPTION
Symptom Chart (Cont'd)
AT-82

Items Symptom Condition Diagnostic Item Reference Page
Improper Shift
TimingKickdown oper-
ates or engine
overruns when
depressing pedal
in D
4beyond kick-
down vehicle
speed limit.ON vehicle1. Vehicle speed sensor´A/T (Revolution
sensor) and vehicle speed sensor´MTRAT- 111 , 1 9 7
2. Throttle position sensor (Adjustment) EC-174
3. Shift solenoid valve A AT-168
4. Shift solenoid valve B AT-172
Gear change from
2
2to 23in 2 posi-
tion.ON vehicle1. Park/neutral position (PNP) switch
adjustmentAT-276
Gear change from
1
1to 12in 1 posi-
tion.ON vehicle1. Park/neutral position (PNP) switch
adjustmentAT-276
2. Manual control linkage adjustment AT-276
No Down ShiftFailure to change
gear from D
4to
D
3.ON vehicle1. Fluid level AT-59
2. Throttle position sensor (Adjustment) EC-174
3. Overrun clutch solenoid valve AT-185
4. Shift solenoid valve A AT-168
5. Line pressure solenoid valve AT-162
6. Control valve assembly AT-273
OFF vehicle7. Low & reverse brake AT-324
8. Overrun clutch AT-320
Failure to change
gear from D
3to
D
2or from D4to
D
2.ON vehicle1. Fluid level AT-59
2. Throttle position sensor (Adjustment) EC-174
3. Shift solenoid valve A AT-168
4. Shift solenoid valve B AT-172
5. Control valve assembly AT-273
OFF vehicle6. High clutch AT-317
7. Brake band AT-333
Failure to change
gear from D
2to
D
1or from D3to
D
1.ON vehicle1. Fluid level AT-59
2. Throttle position sensor (Adjustment) EC-174
3. Shift solenoid valve A AT-168
4. Shift solenoid valve B AT-172
5. Control valve assembly AT-273
OFF vehicle6. Low one-way clutch AT-328
7. High clutch AT-317
8. Brake band AT-333
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TROUBLE DIAGNOSIS Ð GENERAL DESCRIPTION
Symptom Chart (Cont'd)
AT-83