cruise control INFINITI QX4 2001 Factory Service Manual

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

Item DisplayMonitor item
Description Remarks
TCM input
signalsMain sig-
nals
1 position switch 1 POSITION SW
[ON/OFF]
XÐION/OFF status, com-
puted from signal of 1
position SW, is dis-
played.
ASCD cruise signal ASCD-CRUISE
[ON/OFF]
XÐIStatus of ASCD cruise
signal is displayed.
ON ... Cruising state
OFF ... Normal running
stateIThis is displayed even
when no ASCD is
mounted.
ASCD OD cut signal ASCD-OD CUT
[ON/OFF]
XÐIStatus of ASCD OD
release signal is dis-
played.
ON ... OD released
OFF ... OD not releasedIThis is displayed even
when no ASCD is
mounted.
Kickdown switch KICKDOWN SW
[ON/OFF]
XÐION/OFF status, com-
puted from signal of
kickdown SW, is dis-
played.IThis is displayed even
when no kickdown
switch is equipped.
Closed throttle position
switchCLOSED
THL/SW
[ON/OFF]XÐION/OFF status, com-
puted from signal of
closed throttle position
SW, is displayed.
Wide open throttle position
switchW/O THRL/P-SW
[ON/OFF]
XÐION/OFF status, com-
puted from signal of
wide open throttle posi-
tion SW, is displayed.
Stop lamp switch BRAKE SW
[ON/OFF]
XÐION/OFF status is dis-
played.
ON ... Brake pedal is
depressed.
OFF ... Brake pedal is
released.
Gear position GEAR
ÐXIGear position data used
for computation by TCM,
is displayed.
Selector lever position SLCT LVR POSI
ÐXISelector lever position
data, used for computa-
tion by TCM, is dis-
played.IA specific value used for
control is displayed if
fail-safe is activated due
to error.
Vehicle speed VEHICLE
SPEED
[km/h] or [mph]ÐXIVehicle speed data,
used for computation by
TCM, is displayed.
Throttle position THROTTLE
POSI
[/8]ÐXIThrottle position data,
used for computation by
TCM, is displayed.IA specific value used for
control is displayed if
fail-safe is activated due
to error.
Line pressure duty LINE PRES DTY
[%]
ÐXIControl value of line
pressure solenoid valve,
computed by TCM from
each input signal, is dis-
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ON BOARD DIAGNOSTIC SYSTEM DESCRIPTION
CONSULT-II (Cont'd)
AT-41

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

Cruise Test Ð Part 1=NBAT0024S0404
1 CHECK STARTING GEAR (D1) POSITION
1. Drive vehicle for approx. 10 minutes to warm engine oil and ATF up to operating temperature.
ATF operating temperature:
50 - 80ÉC (122 - 176ÉF)
2. Park vehicle on flat surface.
3. Set overdrive control switch to ªONº position.
4. Move selector lever to ªPº position.
SAT001J
5. Start engine.
6. Move selector lever to ªDº position.
SAT952I
7. Accelerate vehicle by constantly depressing accelerator pedal halfway.
SAT953I
8. Does vehicle start from D1?
Read gear position.
YesorNo
Ye s©GO TO 2.
No©Go to ª8. Vehicle Cannot Be Started From D
1º, AT-233.
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TROUBLE DIAGNOSIS Ð BASIC INSPECTION
Road Test (Cont'd)
AT-71

Cruise Test Ð Part 2=NBAT0024S0405
1 CHECK STARTING GEAR (D1) POSITION
1. Confirm overdrive control switch is in ªONº position.
2. Confirm selector lever is in ªDº position.
3. Accelerate vehicle by half throttle again.
4. Does vehicle start from D
1?
Read gear position.
SAT495G
YesorNo
Ye s©GO TO 2.
No©Go to ª16. Vehicle Does Not Start From D
1º, AT-252.
2 CHECK SHIFT UP AND SHIFT DOWN (D3TO D4TO D2)
1. Accelerate vehicle to 80 km/h (50 MPH) as shown in illustration.
2. Release accelerator pedal and then quickly depress it fully.
3. Does A/T shift from D
4to D2as soon as accelerator pedal is depressed fully?
Read gear position and throttle position.
SAT404H
YesorNo
Ye s©GO TO 3.
No©Go to ª9. A/T Does Not Shift: D
3,D4Or Does Not Kickdown: D4,D2º, AT-236.
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TROUBLE DIAGNOSIS Ð BASIC INSPECTION
Road Test (Cont'd)
AT-75

Cruise Test Ð Part 3=NBAT0024S0406
1 VEHICLE SPEED D4POSITION
1. Confirm overdrive control switch is in ªONº position.
2. Confirm selector lever is in ªDº position.
3. Accelerate vehicle using half-throttle to D
4.
SAT812A
©GO TO 2.
2 CHECK SHIFT DOWN (D4TO D3)
1. Release accelerator pedal.
2. Set overdrive control switch to ªOFFº position while driving in D
4.
3. Does A/T shift from D
4to D3(O/D OFF)?
Read gear position and vehicle speed.
SAT999IA
YesorNo
Ye s©GO TO 3.
No©Go to ª17. A/T Does Not Shift: D
4,D3, When Overdrive Control Switch ªONº,ªOFFº,
AT-253.
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TROUBLE DIAGNOSIS Ð BASIC INSPECTION
Road Test (Cont'd)
AT-77

Terminal
No.Wire color Item ConditionJudgement
standard
(Approx.)
11 L/WShift solenoid
valve A
When shift solenoid valve A operates.
(When driving in ªD
1ºorªD4º.)Battery volt-
age
When shift solenoid valve A does not operate.
(When driving in ªD
2ºorªD3º.)0V
12 L/RShift solenoid
valve BWhen shift solenoid valve B operates.
(When driving in ªD
1ºorªD2º.)Battery volt-
age
When shift solenoid valve B does not operate.
(When driving in ªD
3ºorªD4º.)0V
13 GYO/D OFF indica-
tor lamp
When setting overdrive control switch in ªONº
position.Battery volt-
age
When setting overdrive control switch in
ªOFFº position.0V
14 Ð Ð Ð Ð
15 Ð Ð Ð Ð
16 OR/WClosed throttle
position switch
(in throttle posi-
tion switch)When releasing accelerator pedal after warm-
ing up engine.
Refer to ªPreparationº, ªTCM SELF-DIAG-
NOSTIC PROCEDURE (No Tools)º, AT-46.Battery volt-
age
When depressing accelerator pedal after
warming up engine.
Refer to ªPreparationº, ªTCM SELF-DIAG-
NOSTIC PROCEDURE (No Tools)º, AT-46.0V
17 OR/BWide open
throttle position
switch
(in throttle posi-
tion switch)When depressing accelerator pedal more than
half-way after warming up engine.Battery volt-
age
When releasing accelerator pedal after warm-
ing up engine.0V
18 B/YASCD cruise sig-
nal
When ASCD cruise is being performed.
(ªCRUISEº light comes on.)Battery volt-
age
When ASCD cruise is not being performed.
(ªCRUISEº light does not comes on.)0V
19 W/R Power source
Same as No. 10
20 L/BOverrun clutch
solenoid valve
When overrun clutch solenoid valve operates.Battery volt-
age
When overrun clutch solenoid valve does not
operate.0V
21 Ð Ð
ÐÐ
22 GYOverdrive control
switchWhen setting overdrive control switch in ªONº
positionBattery volt-
age
When setting overdrive control switch in
ªOFFº position0V
23 Ð Ð Ð Ð
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TROUBLE DIAGNOSIS Ð GENERAL DESCRIPTION
TCM Terminals and Reference Value (Cont'd)
AT-93

7 CHECK CONTROL VALVE
1. Disassemble control valve assembly. Refer to AT-301.
2. Check line pressure circuit valves for sticking.
IPressure regulator valve
IPilot valve
IPressure modifier valve
SAT367H
OK or NG
OK©GO TO 8.
NG©Repair control valve.
8 CHECK SHIFT UP (D3TO D4)
Does A/T shift from D3to D4at the specified speed?
OK or NG
OK©GO TO 9.
NG©Check control valve again. Repair or replace control valve assembly.
9 CHECK DTC
Perform Diagnostic Trouble Code (DTC) confirmation procedure, AT-140.
OK or NG
OK©INSPECTION END
NG©Perform ªCruise test Ð Part 1º again and return to the start point of this flow chart.
DTC P0734 IMPROPER SHIFTING TO 4TH GEAR POSITION
Diagnostic Procedure (Cont'd)
AT-146

Diagnostic Procedure=NBAT0055
1 CHECK SHIFT UP (D3TO D4)
During ªCruise test þ Part 1º, AT-71.
Does A/T shift from D
3to D4at the specified speed?
SAT988H
YesorNo
Ye s©IGO TO 10.
IAnd check for proper lock-up.
No©GO TO 2.
2 CHECK LINE PRESSURE
Perform line pressure test. Refer to AT-62.
OK or NG
OK©GO TO 3.
NG©GO TO 6.
3 CHECK CONTROL VALVE
1. Disassemble control valve assembly. Refer to AT-301.
2. Check to ensure that:
IValve, sleeve and plug slide along valve bore under their own weight.
IValve, sleeve and plug are free from burrs, dents and scratches.
IControl valve springs are free from damage, deformation and fatigue.
IHydraulic line is free from obstacles.
SAT367H
OK or NG
OK©GO TO 4.
NG©Repair control valve.
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DTC P0744 IMPROPER LOCK-UP OPERATION
Diagnostic Procedure
AT-157