INFINITI QX4 2001 Factory Service Manual

2 CHECK ASCD PUMP CIRCUIT
1. Disconnect ASCD control unit harness connector.
2. Check harness for open or short between ASCD control unit and ASCD pump.
SEL269WB
OK or NG
OK©GO TO 3.
NG©Repair harness.
3 CHECK ASCD PUMP POWER SUPPLY
1. Jack-up the drive wheels.
2. Maintain the conditions below.
IVehicle speed is more than 40 km/h (25 MPH).
IMain switch (CRUISE lamp) is ON.
ISet/coast switch (SET lamp) is ON.
Check voltage between ASCD control unit harness connector terminal 12 and ground.
SEL381WB
OK or NG
OK©ASCD pump power supply is OK.
NG©Replace ASCD control unit.
AUTOMATIC SPEED CONTROL DEVICE (ASCD)
Trouble Diagnoses (Cont'd)
EL-236

ASCD ACTUATOR/PUMP CHECK=NBEL0218S08
1 CHECK VACUUM HOSE
Check vacuum hose (between ASCD actuator and ASCD pump) for breakage, cracks or fracture.
MEL402G
OK or NG
OK©GO TO 2.
NG©Repair or replace hose.
2 CHECK ASCD WIRE
Check wire for improper installation, rust formation or breaks.
OK or NG
OK©GO TO 3.
NG©Repair or replace wire. Refer to ªASCD Wire Adjustmentº (EL-240).
3 CHECK ASCD ACTUATOR
1. Disconnect vacuum hose from ASCD actuator.
2. Connect the hose of hand vacuum pump to ASCD actuator.
SEL264W
OK or NG
OK©GO TO 4.
NG©Replace ASCD actuator.
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AUTOMATIC SPEED CONTROL DEVICE (ASCD)
Trouble Diagnoses (Cont'd)
EL-237

4 CHECK ASCD PUMP
1. Disconnect vacuum hose from ASCD pump and ASCD pump connector.
2. If necessary remove ASCD pump.
3. Connect vacuum gauge to ASCD pump.
4. Apply 12V direct current to ASCD pump and check operation.
SEL265WB
OK or NG
OK©INSPECTION END
NG©Replace ASCD pump.
AUTOMATIC SPEED CONTROL DEVICE (ASCD)
Trouble Diagnoses (Cont'd)
EL-238

SEL302X
Electrical Component Inspection=NBEL0219ASCD BRAKE SWITCH AND STOP LAMP SWITCHNBEL0219S02
ConditionContinuity
ASCD brake
switchStop lamp switch
When brake pedal is depressed No Yes
When brake pedal is released Yes No
Check each switch after adjusting brake pedal Ð refer to BR-14,
ªBRAKE PEDAL AND BRACKETº.
SEL303X
PARK/NEUTRAL POSITION SWITCHNBEL0219S03
A/T selector lever positionContinuity
Between terminals 1 and 2
ªPº Yes
ªNº Yes
Except ªPº and ªNº No
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AUTOMATIC SPEED CONTROL DEVICE (ASCD)
Electrical Component Inspection
EL-239

ASCD Wire Adjustment=NBEL0220
MEL383K
CAUTION:
IBe careful not to twist ASCD wire when removing it.
IDo not tense ASCD wire excessively during adjustment.
Adjust the tension of ASCD wire in the following manner.
1. Loosen lock nut and adjusting nut.
2. Make sure that accelerator wire is properly adjusted. Refer to
FE-3, ªACCELERATOR CONTROL SYSTEMº.
3. Tighten adjusting nut just until throttle drum starts to move.
4. Loosen adjusting nut again 1/2 to 1 turn.
5. Tighten lock nut.
AUTOMATIC SPEED CONTROL DEVICE (ASCD)
ASCD Wire Adjustment
EL-240

System DescriptionNBEL0102Power is supplied at all times
Ifrom 40A fusible link (letterf, located in the fuse and fusible link box)
Ito circuit breaker terminal 1
Ithrough circuit breaker terminal 2
Ito power window relay terminal 3,
Ito front power window main switch terminal 4, and
Ito front power window switch RH terminal 6.
With ignition switch in ON or START position, power is supplied
Ithrough 7.5A fuse [No. 11, located in the fuse block (J/B)]
Ito power window relay terminal 2, and
Ito smart entrance control unit terminal 33.
Ground is supplied to power window relay terminal 1
Ithrough body grounds M4, M66 and M147.
The power window relay is energized and power is supplied
Ithrough power window relay terminal 5
Ito front power window main switch terminal 11,
Ito front power window switch RH terminal 13,
Ito rear power window switch LH and RH terminals 5.
MANUAL OPERATIONNBEL0102S01Front Door LHNBEL0102S0101Ground is supplied
Ito front power window main switch terminal 5
Ithrough body grounds M77 and M111.
WINDOW UP
When the front LH switch in the front power window main switch is pressed in the up position, power is sup-
plied
Ito front power window regulator LH terminal 1
Ithrough front power window main switch terminal 2.
Ground is supplied
Ito front power window regulator LH terminal 3
Ithrough front power window main switch terminal 3.
Then, the motor raises the window until the switch is released.
WINDOW DOWN
When the LH switch in the front power window main switch is pressed in the down position, power is supplied
Ito front power window regulator LH terminal 3
Ithrough front power window main switch terminal 3.
Ground is supplied
Ito front power window regulator LH terminal 1
Ithrough front power window main switch terminal 2.
Then, the motor lowers the window until the switch is released.
Front Door RHNBEL0102S0102Ground is supplied
Ito front power window main switch terminal 5
Ithrough body grounds M77 and M111.
NOTE:
Numbers in parentheses are terminal numbers, when power window switch is pressed in the UP and DOWN
positions respectively.
FRONT POWER WINDOW MAIN SWITCH OPERATION
When front RH switch in the front power window main switch is pressed UP or DOWN, a signal is supplied
Ithrough front power window main switch terminal 8
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POWER WINDOW
System Description
EL-241

Ito front power window switch RH terminal 11.
The subsequent operation is the same as the front power window switch RH operation.
FRONT POWER WINDOW SWITCH RH OPERATION
Power is supplied
Ithrough front power window switch RH (5, 4)
Ito front power window regulator RH (1, 3).
Ground is supplied
Ito front power window regulator RH (3, 1)
Ithrough front power window switch RH (4, 5)
Ito front power window switch RH terminal 12
Ithrough front power window main switch terminal 1.
Then, the motor raises or lowers the window until the switch is released.
Rear Door LHNBEL0102S0104Ground is supplied
Ito front power window main switch terminal 5
Ithrough body grounds the M77 and M111.
NOTE:
Numbers in parentheses are terminal numbers, when the power window switch is pressed in the UP and
DOWN positions.
FRONT POWER WINDOW MAIN SWITCH OPERATION
Power is supplied
Ithrough front power window main switch terminal (13, 12)
Ito rear power window switch LH terminal (3, 4)
The subsequent operation is the same as the rear power window switch LH operation.
REAR POWER WINDOW SWITCH LH
Power is supplied
Ithrough rear power window switch LH (1, 2)
Ito rear power window regulator LH (1, 2)
Ground is supplied
Ito rear power window regulator LH (2, 1)
Ithrough rear power window switch LH (2, 1)
Ito rear power window switch LH terminal (4, 3)
Ithrough front power window main switch terminal (12, 13)
Then, the motor raises or lowers the window until the switch is released.
Rear Door RHNBEL0102S0105Rear door RH windows will rise and lower in the same manner as the rear door LH window.
AUTO OPERATIONNBEL0102S02The power window AUTO feature enables the driver or front passenger to open or close the driver's and front
passenger's window without holding the window switch in the up or down position.
The AUTO feature only operates on the driver's and front passenger's window upward and downward move-
ment.
POWER WINDOW LOCKNBEL0102S03The power window lock is designed to lock operation of all windows except for driver's door window.
When the lock switch is pressed to lock position, the ground of the front and rear power window switches, in
the power window main switch, is disconnected. This prevents the power window motors from operating.
RETAINED POWER OPERATIONNBEL0102S04When the ignition switch is turned to OFF position from ON or START position, power is supplied for 45 sec-
onds
Ito power window relay terminal 2
Ifrom smart entrance control unit terminal 5.
Ground is always supplied
POWER WINDOW
System Description (Cont'd)
EL-242

Ito power window relay terminal 1
Ithrough body grounds.
When power and ground are supplied, the power window relay continues to be energized, and the power win-
dow can be operated.
The retained power operation is canceled when the driver or passenger side door is opened.
INTERRUPTION DETECTION FUNCTIONNBEL0102S05Front power window main switch and front power window switch RH monitor the power window regulator motor
operation and the power window position (full closed or other) for driver's and passenger's power window by
the signals from encoder and limit switch in front power window regulator LH or RH.
When front power window main switch or front power window switch RH detects interruption during the fol-
lowing close operation in the driver's or front passenger's side door,
Iautomatic close operation when ignition switch is in the ªONº position
Iautomatic close operation during retained power operation
front power window main switch or front power window switch RH controls driver's or front passenger's power
window regulator motor for open and the power window will be lowered about 150 mm (5.91 in).
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POWER WINDOW
System Description (Cont'd)
EL-243

SchematicNBEL0103
MEL842L
POWER WINDOW
Schematic
EL-244

Wiring Diagram Ð WINDOW ÐNBEL0104
MEL008O
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POWER WINDOW
Wiring Diagram Ð WINDOW Ð
EL-245