2001 INFINITI QX4 engine

SAT631IB
IntroductionNBAT0019
SAT632I
SEF234G
The TCM receives a signal from the vehicle speed 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
capable of diagnosing malfunctioning parts while the ECM can
store malfunctions 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
operating condition and be free of valve seizure, solenoid valve
malfunction, etc.
It is much more difficult to diagnose a problem that occurs intermit-
tently rather than continuously. Most intermittent problems are
caused by poor electric connections or improper wiring. In this
case, careful checking of suspected circuits may help prevent the
replacement of good parts.
A visual check only may not find the cause of the problems. A road
test with CONSULT-II (or GST) or a circuit tester connected should
be performed. Follow the ªWork Flowº. Refer to AT-57.
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 problems, espe-
cially intermittent ones. Find out what symptoms are present and
under what conditions they occur. A ªDiagnostic Worksheetº like the
example (AT-55) should be used.
Start your diagnosis by looking for ªconventionalº problems first.
This will help troubleshoot driveability problems on an electronically
controlled engine vehicle.
Also check related Service bulletins.GI
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TROUBLE DIAGNOSIS Ð INTRODUCTION
Introduction
AT-53

DIAGNOSTIC WORKSHEET=NBAT0019S01Information From CustomerNBAT0019S0101KEY POINTS
WHAT..... Vehicle & A/T model
WHEN..... Date, Frequencies
WHERE..... Road conditions
HOW..... Operating conditions, Symptoms
Customer name MR/MS Model & Year VIN
Trans. model Engine Mileage
Incident Date Manuf. Date In Service Date
FrequencylContinuouslIntermittent ( times a day)
SymptomslVehicle does not move. (lAny positionlParticular position)
lNo up-shift (l1st,2ndl2nd,3rdl3rd,O/D)
lNo down-shift (lO/D,3rdl3rd,2ndl2nd,1st)
lLockup malfunction
lShift point too high or too low.
lShift shock or slip (lN,DlLockuplAny drive position)
lNoise or vibration
lNo kickdown
lNo pattern select
lOthers
()
O/D OFF indicator lamp Blinks for about 8 seconds.
lContinuously litlNot lit
Malfunction indicator lamp (MIL)lContinuously litlNot lit
TROUBLE DIAGNOSIS Ð INTRODUCTION
Introduction (Cont'd)
AT-54

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

A/T Fluid CheckNBAT0021FLUID LEAKAGE CHECKNBAT0021S011. Clean area suspected of leaking. Ð for example, mating sur-
face of converter housing and transmission case.
2. Start engine, apply foot brake, place selector lever in ªDº posi-
tion and wait a few minutes.
3. Stop engine.
4. Check for fresh leakage.
SAT638A
FLUID CONDITION CHECKNBAT0021S02
Fluid color Suspected problem
Dark or black with burned odor Wear of frictional material
Milky pinkWater contamination Ð Road water
entering through filler tube or breather
Varnished fluid, light to dark brown
and tackyOxidation Ð Over or under filling, Ð
Overheating
FLUID LEVEL CHECKNBAT0021S03Refer to MA-21, ªChecking A/T Fluidº.
SAT647B
Stall TestNBAT0022STALL TEST PROCEDURENBAT0022S011. Check A/T fluid and engine oil levels. If necessary, add fluid
and oil.
2. Drive vehicle for approx. 10 minutes or until fluid and oil reach
operating temperature.
ATF operating temperature:
50 - 80ÉC (122 - 176ÉF)
SAT513G
3. Set parking brake and block wheels.
4. Install a tachometer where it can be seen by driver during test.
IIt is good practice to put a mark on point of specified
engine rpm on indicator.
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TROUBLE DIAGNOSIS Ð BASIC INSPECTION
A/T Fluid Check
AT-59

SAT514G
5. Start engine, apply foot brake, and place selector lever in ªDº
position.
6. Accelerate to wide open throttle gradually while applying foot
brake.
7. Quickly note the engine stall revolution and immediately
release throttle.
IDuring test, never hold throttle wide open for more than 5
seconds.
Stall revolution:
Refer to SDS, AT-356.
SAT771B
8. Move selector lever to ªNº position.
9. Cool off ATF.
IRun engine at idle for at least one minute.
10. Repeat steps 5 through 9 with selector lever in ª2º, ª1º and ªRº
positions.
JUDGEMENT OF STALL TESTNBAT0022S02The test result and possible damaged components relating to each
result are shown in the illustration. In order to pinpoint the possible
damaged components, refer to ªWork Flowº, AT-57.
NOTE:
Stall revolution is too high in ªDº or ª2º position:
ISlippage occurs in 1st gear but not in 2nd and 3rd gears. .....
Low one-way clutch slippage
ISlippage occurs at the following gears:
1st through 3rd gears in ªDº position and engine brake func-
tions.
1st and 2nd gears in ª2º position and engine brake functions
with accelerator pedal released (fully closed throttle). ..... For-
ward clutch or forward one-way clutch slippage
Stall revolution is too high in ªRº position:
IEngine brake does not function in ª1º position. ..... Low &
reverse brake slippage
IEngine brake functions in ª1º position. ..... Reverse clutch slip-
page
Stall revolution within specifications:
IVehicle does not achieve speed of more than 80 km/h (50
MPH). ..... One-way clutch seizure in torque converter housing
CAUTION:
Be careful since automatic fluid temperature increases abnor-
mally.
ISlippage occurs in 3rd and 4th gears in ªDº position. ..... High
clutch slippage
ISlippage occurs in 2nd and 4th gear in ªDº position. ..... Brake
band slippage
Stall revolution less than specifications:
IPoor acceleration during starts. ..... One-way clutch seizure in
torque converter
TROUBLE DIAGNOSIS Ð BASIC INSPECTION
Stall Test (Cont'd)
AT-60

SAT209GA
Line Pressure TestNBAT0023ILocation of line pressure test ports.
IAlways replace line pressure plugs as they are self-seal-
ing bolts.
SAT647B
LINE PRESSURE TEST PROCEDURENBAT0023S011. Check A/T fluid and engine oil levels. If necessary, add fluid
and oil.
2. Drive vehicle for approx. 10 minutes or until fluid and oil reach
operating temperature.
ATF operating temperature:
50 - 80ÉC (122 - 176ÉF)
SAT518GB
SAT519GB
3. Install pressure gauge to corresponding line pressure port.
SAT513G
4. Set parking brake and block wheels.
IContinue to depress brake pedal fully while line pressure
test is being performed at stall speed.
TROUBLE DIAGNOSIS Ð BASIC INSPECTION
Line Pressure Test
AT-62

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