Engine control INFINITI QX4 2001 Factory Owner's Manual

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

Symptom ChartNBAT0233Numbers are arranged in order of inspection.
Perform inspections starting with number one and work up.
Items Symptom Condition Diagnostic Item Reference Page
No Lock-up
Engagement/TCC
InoperativeTorque converter
is not locked up.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. Park/neutral position (PNP) switch
adjustmentAT-276
4. Engine speed signal AT-116
5. A/T fluid temperature sensor AT-105
6. Line pressure test AT-62
7. Torque converter clutch solenoid valve AT-148
8. Control valve assembly AT-273
OFF vehicle 9. Torque converter AT-286
Torque converter
clutch piston slip.ON vehicle1. Fluid level AT-59
2. Throttle position sensor (Adjustment) EC-174
3. Line pressure test AT-62
4. Torque converter clutch solenoid valve AT-148
5. Line pressure solenoid valve AT-162
6. Control valve assembly AT-273
OFF vehicle 7. Torque converter AT-286
Lock-up point is
extremely high or
low.
AT-245ON 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. Torque converter clutch solenoid valve AT-148
4. Control valve assembly AT-273
Shift ShockSharp shock in
shifting from N to
D position.ON vehicle1. Engine idling rpm EC-431
2. Throttle position sensor (Adjustment) EC-174
3. Line pressure test AT-62
4. A/T fluid temperature sensor AT-105
5. Engine speed signal AT-116
6. Line pressure solenoid valve AT-162
7. Control valve assembly AT-273
8. Accumulator N-D AT-273
OFF vehicle9. Turbine revolution sensor EC-368
10. Forward clutch AT-320
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TROUBLE DIAGNOSIS Ð GENERAL DESCRIPTION
Symptom Chart
AT-81

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

Items Symptom Condition Diagnostic Item Reference Page
Slips/Will Not
EngageRaces extremely
fast or slips in
changing from D
4or D3to D1when
depressing pedal.ON vehicle1. Fluid level AT-59
2. Throttle position sensor (Adjustment) EC-174
3. Line pressure test AT-62
4. Line pressure solenoid valve AT-162
5. Control valve assembly AT-273
OFF vehicle6. Forward clutch AT-320
7. Forward one-way clutch AT-330
8. Low one-way clutch AT-328
Vehicle will not
run in any posi-
tion.ON vehicle1. Fluid level AT-59
2. Manual control linkage adjustment AT-276
3. Line pressure test AT-62
4. Line pressure solenoid valve AT-162
OFF vehicle5. Oil pump AT-297
6. High clutch AT-317
7. Brake band AT-333
8. Low & reverse brake AT-324
9. Torque converter AT-286
10. Parking pawl components AT-337
NOT USEDEngine cannot be
started in P and N
positions.
AT-221ON vehicle1. Ignition switch and starter EL-9, and SC-10
2. Manual control linkage adjustment AT-276
3. Park/neutral position (PNP) switch
adjustmentAT-276
Engine starts in
positions other
than P and N.
AT-221ON vehicle1. Manual control linkage adjustment AT-276
2. Park/neutral position (PNP) switch
adjustmentAT-276
Transmission
noise in P and N
positions.ON vehicle1. Fluid level AT-59
2. Line pressure test AT-62
3. Throttle position sensor (Adjustment) EC-174
4. Vehicle speed sensor´A/T (Revolution
sensor) and vehicle speed sensor´MTRAT- 111 , 1 9 7
5. Engine speed signal AT-116
OFF vehicle6. Oil pump AT-297
7. Torque converter AT-286
Vehicle moves
when changing
into P position or
parking gear does
not disengage
when shifted out
of P position.
AT-222ON vehicle 1. Manual control linkage adjustment AT-276
OFF vehicle 2. Parking pawl components AT-337
TROUBLE DIAGNOSIS Ð GENERAL DESCRIPTION
Symptom Chart (Cont'd)
AT-88

Items Symptom Condition Diagnostic Item Reference Page
NOT USEDVehicle runs in N
position.
AT-223ON vehicle 1. Manual control linkage adjustment AT-276
OFF vehicle2. Forward clutch AT-320
3. Reverse clutch AT-314
4. Overrun clutch AT-320
Vehicle braked
when shifting into
R position.ON vehicle1. Fluid level AT-59
2. Manual control linkage adjustment AT-276
3. Line pressure test AT-62
4. Line pressure solenoid valve AT-162
5. Control valve assembly AT-273
OFF vehicle6. High clutch AT-317
7. Brake band AT-333
8. Forward clutch AT-320
9. Overrun clutch AT-320
Excessive creep. ON vehicle 1. Engine idling rpm EC-431
Engine stops
when shifting
lever into R, D, 2
and 1.ON vehicle1. Engine idling rpm EC-431
2. Torque converter clutch solenoid valve AT-148
3. Control valve assembly AT-273
OFF vehicle 4. Torque converter AT-286
Vehicle braked by
gear change from
D
1to D2.ON vehicle 1. Fluid level AT-59
OFF vehicle2. Reverse clutch AT-314
3. Low & reverse brake AT-324
4. High clutch AT-317
5. Low one-way clutch AT-328
Vehicle braked by
gear change from
D
2to D3.ON vehicle 1. Fluid level AT-59
OFF vehicle 2. Brake band AT-333
Vehicle braked by
gear change from
D
3to D4.ON vehicle 1. Fluid level AT-59
OFF vehicle2. Overrun clutch AT-320
3. Forward one-way clutch AT-330
4. Reverse clutch AT-314
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TROUBLE DIAGNOSIS Ð GENERAL DESCRIPTION
Symptom Chart (Cont'd)
AT-89

Items Symptom Condition Diagnostic Item Reference Page
NOT USEDMaximum speed
not attained.
Acceleration poor.ON vehicle1. Fluid level AT-59
2. Park/neutral position (PNP) switch
adjustmentAT-276
3. Shift solenoid valve A AT-168
4. Shift solenoid valve B AT-172
5. Control valve assembly AT-273
OFF vehicle6. Reverse clutch AT-314
7. High clutch AT-317
8. Brake band AT-333
9. Low & reverse brake AT-324
10. Oil pump AT-297
11. Torque converter AT-286
Transmission
noise in D, 2, 1
and R positions.ON vehicle 1. Fluid level AT-59
ON vehicle 2. Torque converter AT-286
Engine brake
does not operate
in ª1º position.
AT-252ON vehicle1. Park/neutral position (PNP) switch
adjustmentAT-276
2. Manual control linkage adjustment AT-276
3. Throttle position sensor (Adjustment) EC-174
4. Vehicle speed sensor´A/T (Revolution
sensor) and vehicle speed sensor´MTRAT- 111 , 1 9 7
5. Shift solenoid valve A AT-168
6. Control valve assembly AT-273
7. Overrun clutch solenoid valve AT-185
OFF vehicle8. Overrun clutch AT-320
9. Low & reverse brake AT-324
Transmission
overheats.ON vehicle1. Fluid level AT-59
2. Engine idling rpm EC-431
3. Throttle position sensor (Adjustment) EC-174
4. Line pressure test AT-62
5. Line pressure solenoid valve AT-162
6. Control valve assembly AT-273
OFF vehicle7. Oil pump AT-297
8. Reverse clutch AT-314
9. High clutch AT-317
10. Brake band AT-333
11. Forward clutch AT-320
12. Overrun clutch AT-320
13. Low & reverse brake AT-324
14. Torque converter AT-286
TROUBLE DIAGNOSIS Ð GENERAL DESCRIPTION
Symptom Chart (Cont'd)
AT-90

Items Symptom Condition Diagnostic Item Reference Page
NOT USEDATF shoots out
during operation.
White smoke
emitted from
exhaust pipe dur-
ing operation.ON vehicle 1. Fluid level AT-59
OFF vehicle2. Reverse clutch AT-314
3. High clutch AT-317
4. Brake band AT-333
5. Forward clutch AT-320
6. Overrun clutch AT-320
7. Low & reverse brake AT-324
Offensive smell at
fluid charging
pipe.ON vehicle 1. Fluid level AT-59
OFF vehicle2. Torque converter AT-286
3. Oil pump AT-297
4. Reverse clutch AT-314
5. High clutch AT-317
6. Brake band AT-333
7. Forward clutch AT-320
8. Overrun clutch AT-320
9. Low & reverse brake AT-324
Engine is stopped
at R, D, 2 and 1
positions.ON vehicle1. Fluid level AT-59
2. Torque converter clutch solenoid valve AT-148
3. Shift solenoid valve B AT-172
4. Shift solenoid valve A AT-168
5. Control valve assembly AT-273
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TROUBLE DIAGNOSIS Ð GENERAL DESCRIPTION
Symptom Chart (Cont'd)
AT-91

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

Terminal
No.Wire color Item ConditionJudgement
standard
(Approx.)
39 W/BEngine speed
signal
Refer to EC-127, ªECM INSPECTION
TABLEº.Ð
40 W/LVehicle speed
sensor
When moving vehicle at 2 to 3 km/h (1 to 2
MPH) for1m(3ft)ormore.Voltage varies
between less
than 1.0V and
more than
4.5V.
41 PThrottle position
sensor
When depressing accelerator pedal slowly
after warming up engine.
(Voltage rises gradually in response to throttle
position.)Fully-closed
throttle:
0.5V - 0.7V
Fully-open
throttle:
4V
42 BThrottle position
sensor
(Ground)Ð0V
45 G/Y Stop lamp switchWhen depressing brake pedalBattery volt-
age
When releasing brake pedal 0V
46 WTransfer control
unitÐÐ
47 RA/T fluid tempera-
ture sensorWhen ATF temperature is 20ÉC (68ÉF). 1.5V
When ATF temperature is 80ÉC (176ÉF). 0.5V
48 B Ground
Ð0V
*1: These terminals are connected to the ECM.
*2: These terminals are connected to the Data link connector for CONSULT-II.
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TROUBLE DIAGNOSIS Ð GENERAL DESCRIPTION
TCM Terminals and Reference Value (Cont'd)
AT-95