2001 INFINITI QX4 elec

Valve name Function
Shift valve A Simultaneously switches three oil circuits using output pressure of shift solenoid valve
A to meet driving conditions (vehicle speed, throttle opening, etc.).
Provides automatic downshifting and up-shifting (1st,2nd,3rd,4th gears/4th
,3rd,2nd,1st gears) in combination with shift valve B.
Shift valve B Simultaneously switches three oil circuits using output pressure of shift solenoid valve
B in relation to driving conditions (vehicle speed, throttle opening, etc.).
Provides automatic downshifting and up-shifting (1st,2nd,3rd,4th gears/4th
,3rd,2nd,1st gears) in combination with shift valve A.
Shuttle shift valve S Switches hydraulic circuits to provide 3-2 timing control and overrun clutch control in
relation to the throttle opening.
Inactivates the overrun clutch to prevent interlocking in 4th gear when the throttle is
wide open.
Overrun clutch control valve Switches hydraulic circuits to prevent engagement of the overrun clutch simulta-
neously with application of the brake band in 4th gear. (Interlocking occurs if the
overrun clutch engages during D
4gear operation.)
4-2 relay valve Memorizes that the transmission is in 4th gear. Prevents the transmission from down-
shifting from 4th gear to 3rd and then to 2nd in combination with 4-2 sequence valve
and shift valves A and B when downshifting from 4th to 2nd gear.
4-2 sequence valve Prevents band servo pressure from draining before high clutch operating pressure
and band servo releasing pressure drain (from the same circuit) during downshifting
from 4th to 2nd gear.
Servo charger valve An accumulator and a one-way orifice are used in the 2nd gear band servo oil circuit
to dampen shifting shock when shifting from 1st to 2nd gear.
To maintain adequate flow rate when downshifting from 4th or 3rd gear to 2nd gear,
the servo charger valve directs 2nd gear band servo hydraulic pressure to the circuit
without going through the one-way orifice when downshifting from 3rd or a higher
gear.
3-2 timing valve Prevents a late operation of the brake band when shifting selector lever from ªDº to
ª1º or ª2º position while driving in D
3.
ª1º reducing valve Reduces low & reverse brake pressure to dampen engine-brake shock when down-
shifting from the ª1º position 2nd gear to 1st gear.
Overrun clutch reducing valve Reduces oil pressure directed to the overrun clutch and prevents engine-brake shock.
In ª1º and ª2º positions, line pressure acts on the overrun clutch reducing valve to
increase the pressure-regulating point, with resultant engine brake capability.
Torque converter relief valve Prevents an excessive rise in torque converter pressure.
Torque converter clutch control valve,
torque converter clutch control plug and
torque converter clutch control sleeveActivate or inactivate the lock-up function.
Also provide smooth lock-up through transient application and release of the lock-up
system.
Shuttle shift valve D Switches hydraulic circuits so that output pressure of the torque converter clutch sole-
noid valve acts on the lock-up valve in the ªDº position of 2nd, 3rd and 4th gears. (In
the ªDº position 1st gear, lock-up is inhibited.)
ILock-up control is not affected in ªDº position 2nd, 3rd or 4th gears, unless output
pressure of the torque converter clutch solenoid valve is generated by a signal
from the control unit.
OVERALL SYSTEM
Control Valve (Cont'd)
AT-32

Priority Items
1 Freeze frame data Misfire Ð DTC: P0300 - P0306
Fuel Injection System Function Ð DTC: P0171, P0172, P0174, P0175
2 Except the above items (Includes A/T related items)
3 1st trip freeze frame data
Both 1st trip freeze frame data and freeze frame data (along with the DTCs) are cleared when the ECM
memory is erased.
HOW TO ERASE DTCNBAT0016S02The diagnostic trouble code can be erased by CONSULT-II, GST or ECM DIAGNOSTIC TEST MODE as
described following.
IIf the battery terminal is disconnected, the diagnostic trouble code will be lost within 24 hours.
IWhen you erase the DTC, using CONSULT-II or GST is easier and quicker than switching the mode
selector on the ECM.
The following emission-related diagnostic information is cleared from the ECM memory when erasing DTC
related to OBD-II. For details, refer to EC-60, ªEmission-related Diagnostic Informationº.
IDiagnostic trouble codes (DTC)
I1st trip diagnostic trouble codes (1st trip DTC)
IFreeze frame data
I1st trip freeze frame data
ISystem readiness test (SRT) codes
ITest values
HOW TO ERASE DTC (WITH CONSULT-II)NBAT0016S03IIf a DTC is displayed for both ECM and TCM, it needs to be erased for both ECM and TCM.
1. If the ignition switch stays ªONº after repair work, be sure to turn ignition switch ªOFFº once. Wait at least
5 seconds and then turn it ªONº (engine stopped) again.
2. Turn CONSULT-II ªONº and touch ªA/Tº.
3. Touch ªSELF-DIAG RESULTSº.
4. Touch ªERASEº. (The DTC in the TCM will be erased.) Then touch ªBACKº twice.
5. Touch ªENGINEº.
6. Touch ªSELF-DIAG RESULTSº.
7. Touch ªERASEº. (The DTC in the ECM will be erased.)
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ON BOARD DIAGNOSTIC SYSTEM DESCRIPTION
OBD-II Diagnostic Trouble Code (DTC) (Cont'd)
AT-35

SAT017K
HOW TO ERASE DTC (WITH GST)NBAT0016S041. If the ignition switch stays ªONº after repair work, be sure to turn ignition switch ªOFFº once. Wait at least
5 seconds and then turn it ªONº (engine stopped) again.
2. Perform ªOBD-II SELF-DIAGNOSTIC PROCEDURE (No Tools)º. Refer to AT-46. (The engine warm-up
step can be skipped when performing the diagnosis only to erase the DTC.)
3. Select Mode 4 with Generic Scan Tool (GST). For details, refer to EC-95, ªDESCRIPTIONº.
HOW TO ERASE DTC (NO TOOLS)NBAT0016S051. If the ignition switch stays ªONº after repair work, be sure to turn ignition switch ªOFFº once. Wait at least
5 seconds and then turn it ªONº (engine stopped) again.
2. Perform ªTCM SELF-DIAGNOSTIC PROCEDURE (No Tools)º. Refer to AT-46. (The engine warm-up step
can be skipped when performing the diagnosis only to erase the DTC.)
ON BOARD DIAGNOSTIC SYSTEM DESCRIPTION
OBD-II Diagnostic Trouble Code (DTC) (Cont'd)
AT-36

SAT964I
Malfunction Indicator Lamp (MIL)=NBAT0183The MIL is located on the instrument panel.
1. The MIL will light up when the ignition switch is turned ON
without the engine running. This is a bulb check.
IIf the MIL does not light up, refer to EL-114, ªSchematicº.
(Or refer to EC-648, ªWiring Diagramº.)
2. When the engine is started, the MIL should go off.
If the MIL remains on, the on board diagnostic system has
detected an engine system malfunction. For detail, refer to
EC-59, ªIntroductionº.
CONSULT-IINBAT0184After performing ªSELF-DIAGNOSTIC PROCEDURE (WITH CON-
SULT-II)º (AT-37), place check marks for results on the ªDIAGNOS-
TIC WORKSHEETº, AT-55. Reference pages are provided follow-
ing the items.
NOTICE:
1) The CONSULT-II electrically displays shift timing and lock-up
timing (that is, operation timing of each solenoid).
Check for time difference between actual shift timing and the
CONSULT-II display. If the difference is noticeable, mechani-
cal parts (except solenoids, sensors, etc.) may be malfunction-
ing. Check mechanical parts using applicable diagnostic pro-
cedures.
2) Shift schedule (which implies gear position) displayed on
CONSULT-II and that indicated in Service Manual may differ
slightly. This occurs because of the following reasons:
IActual shift schedule has more or less tolerance or allowance,
IShift schedule indicated in Service Manual refers to the point
where shifts start, and
IGear position displayed on CONSULT-II indicates the point
where shifts are completed.
3) Shift solenoid valve ªAº or ªBº is displayed on CONSULT-II at
the start of shifting. Gear position is displayed upon completion
of shifting (which is computed by TCM).
4) Additional CONSULT-II information can be found in the Opera-
tion Manual supplied with the CONSULT-II unit.
SAT014K
SELF-DIAGNOSTIC PROCEDURE (WITH CONSULT-II)NBAT0184S011. Turn on CONSULT-II and touch ªENGINEº for OBD-II detected
items or touch ªA/Tº for TCM self-diagnosis.
If A/T is not displayed, check TCM power supply and ground
circuit. Refer to AT-92. If result is NG, refer to EL-9, ªSche-
maticº.
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ON BOARD DIAGNOSTIC SYSTEM DESCRIPTION
Malfunction Indicator Lamp (MIL)
AT-37

SAT987J
2. Touch ªSELF-DIAG RESULTSº.
Display shows malfunction experienced since the last erasing
operation.
CONSULT-II performs REAL-TIME SELF-DIAGNOSIS.
Also, any malfunction detected while in this mode will be dis-
played at real time.
SELF-DIAGNOSTIC RESULT TEST MODENBAT0184S02
Detected items
(Screen terms for CONSULT-II, ªSELF-DIAG
RESULTSº test mode)
Malfunction is detected when ...TCM self-diagnosis OBD-II (DTC)
Available by
O/D OFF
indicator lamp or
ªA/Tº on CONSULT-IIAvailable by
malfunction
indicator lamp*2,
ªENGINEº on CON-
SULT-II or GST ªA/Tº ªENGINEº
PNP switch circuitITCM does not receive the cor-
rect voltage signal (based on
the gear position) from the
switch.Ð P0705
ÐPNP SW/CIRC
Revolution sensorITCM does not receive the
proper voltage signal from the
sensor.X P0720
VHCL SPEED
SEN´A/TVEH SPD SEN/CIR
AT
Vehicle speed sensor (Meter)ITCM does not receive the
proper voltage signal from the
sensor.XÐ
VHCL SPEED
SEN´MTRÐ
A/T 1st gear functionIA/T cannot be shifted to the 1st
gear position even if electrical
circuit is good.Ð P0731*1
ÐA/T 1ST GR FNCTN
A/T 2nd gear functionIA/T cannot be shifted to the 2nd
gear position even if electrical
circuit is good.Ð P0732*1
ÐA/T 2ND GR FNCTN
A/T 3rd gear functionIA/T cannot be shifted to the 3rd
gear position even if electrical
circuit is good.Ð P0733*1
ÐA/T 3RD GR FNCTN
A/T 4th gear functionIA/T cannot be shifted to the 4th
gear position even if electrical
circuit is good.Ð P0734*1
ÐA/T 4TH GR FNCTN
A/T TCC S/V function (lock-up)IA/T cannot perform lock-up
even if electrical circuit is good.Ð P0744*1
Ð A/T TCC S/V FNCTN
Shift solenoid valve AITCM detects an improper volt-
age drop when it tries to operate
the solenoid valve.X P0750
SHIFT SOLENOID/V
ASFT SOL A/CIRC
Shift solenoid valve BITCM detects an improper volt-
age drop when it tries to operate
the solenoid valve.X P0755
SHIFT SOLENOID/V
BSFT SOL B/CIRC
ON BOARD DIAGNOSTIC SYSTEM DESCRIPTION
CONSULT-II (Cont'd)
AT-38

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-
played.GI
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ON BOARD DIAGNOSTIC SYSTEM DESCRIPTION
CONSULT-II (Cont'd)
AT-41

SAT014K
5. Touch ªA/Tº.
SAT971J
6. Touch ªDTC WORK SUPPORTº.
SAT018K
7. Touch select item menu (1ST, 2ND, etc.).
SAT589J
8. Touch ªSTARTº.
SAT019K
9. Perform driving test according to ªDTC CONFIRMATION PRO-
CEDUREº in ªTROUBLE DIAGNOSIS FOR DTCº.
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ON BOARD DIAGNOSTIC SYSTEM DESCRIPTION
CONSULT-II (Cont'd)
AT-43

1 CHECK O/D OFF INDICATOR LAMP
1. Start the engine with selector lever in ªPº position. Warm engine to normal operating temperature.
2. Turn ignition switch to ªOFFº position.
3. Wait 5 seconds.
SAT967I
4. Turn ignition switch to ªONº position.
(Do not start engine.)
5. Does O/D OFF indicator lamp come on for about 2 seconds?
SAT133K
YesorNo
Ye s©GO TO 2.
No©Go to ª1. O/D OFF Indicator Lamp Does Not Come Onº, AT-218.
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ON BOARD DIAGNOSTIC SYSTEM DESCRIPTION
Diagnostic Procedure Without CONSULT-II (Cont'd)
AT-47