2007 INFINITI QX56 ECU

TF-42
< SERVICE INFORMATION >
TROUBLE DIAGNOSIS
CAUTION:
When using a circuit tester to measure voltage for inspection, be sure not to extend forcibly any connector terminals.
CONSULT-II Function (ALL MODE AWD/4WD)INFOID:0000000003532527
FUNCTION
CONSULT-II can display each diagnostic item using the diagnostic test modes shown following.
41 RTransfer motor relay moni-
tor• Accelerator pedal
depressed
• Vehicle stopped
• Engine running
• Brake pedal de-
pressed4WD shift switch: 2WD 0V
4WD shift switch: AUTO or 4LO (A/T selec-
tor lever “P” or “N” position)0V
(Battery volt-
age for approx.
2 sec. after
shifting to “P”
and “N”.)
4WD shift switch: AUTO or 4LO (Except for
A/T selector lever “P” or “N” position)Battery voltage
4WD shift switch: 4H (A/T selector lever
“P” position)0V
(Battery volt-
age for approx.
2 sec. after
shifting to “P”.)
4WD shift switch: 4H (Except for A/T selec-
tor lever “P” position)Battery voltage
42 P/GTransfer shift low relay
monitor• Vehicle stopped
• Engine running
• A/T selector lever
“N” position
• Brake pedal de-
pressed4WD shift switch: 4LO to 4H (“Wait” func-
tion is operating.)Battery voltage
Except the above 0V
43 G/Y Wait detection switch• Vehicle stopped
• Engine running
• A/T selector lever
“N” position
• Brake pedal de-
pressed4WD shift switch: 2WD, AUTO or 4H Battery voltage
4WD shift switch: 4H to 4LO (While actua-
tor motor is operating.)Battery voltage
→ 0V
4WD shift switch: 4LO to 4H (While actua-
tor motor is operating.)0V → Battery
voltage
4WD shift switch: 4LO 0V
44 LG/BActuator position switch 1
(Low)• Vehicle stopped
• Engine running
• A/T selector lever
“N” position
• Brake pedal de-
pressed4WD shift switch: 4LO 0V
4WD shift switch: 2WD, AUTO or 4H Battery voltage
45 B Ground Always 0V
47 WPower supply
(Memory back-up)Ignition switch: ON Battery voltage
Ignition switch: OFF Battery voltage Te r m i n a lWire
colorItem Condition Data (Approx.)
ALL MODE AWD/4WD diag-
nostic modeDescription
SELF-DIAG RESULTS Displays transfer control unit self-diagnosis results.
DATA MONITOR Displays transfer control unit input/output data in real time.
WORK SUPPORTSupports inspections and adjustments. Commands are transmitted to the transfer control unit for set-
ting the status suitable for required operation, input/output signals are received from the transfer control
unit and received data is displayed.
CAN DIAG SUPPORT MNTR The results of transmit/receive diagnosis of CAN communication can be read.
ECU PART NUMBER Transfer control unit part number can be read.

TROUBLE DIAGNOSIS
TF-45
< SERVICE INFORMATION >
C
E
F
G
H
I
J
K
L
MA
B
TF
N
O
P
2. Start engine and select “SELF-DIAG RESULTS” mode for “ALL MODE AWD/4WD” with CONSULT-II.
3. Touch “ERASE” on CONSULT-II screen to erase DTC memory.
CAUTION:
If memory cannot be erased, perform applicable diagnosis.
DATA MONITOR MODE
Operation Procedure
Refer to GI-36, "CONSULT-II Start Procedure".
Display Item List
×: Standard –: Not applicable
Monitored item (Unit)Monitor item selection
Remarks
ECU INPUT
SIGNALSMAIN
SIGNALSSELEC-
TION FROM
MENU
VHCL/S SEN·FR [km/h] or [mph]×–×Wheel speed calculated by ABS actuator and
electric unit (control unit).
Signal input with CAN communication line.
VHCL/S SEN·RR [km/h] or [mph]×–×Wheel speed calculated by TCM.
Signal input with CAN communication line.
ENGINE SPEED [rpm]×–×Engine speed calculated by ECM.
Signal input with CAN communication line.
THRTL POS SEN [V]×–×Accelerator pedal position (APP) sensor sig-
nal voltage is displayed.
Signal input with CAN communication line.
FLUID TEMP SE [V]×–×Transfer fluid temperature sensor signal volt-
age is displayed.
BATTERY VOLT [V]×–×Power supply voltage for transfer control unit.
2WD SWITCH [ON/OFF]×–×4WD shift switch status is displayed.
AUTO SWITCH [ON/OFF]×–×4WD shift switch status is displayed.
LOCK SWITCH [ON/OFF]×–×4WD shift switch status is displayed.
(LOCK means 4H of 4WD shift switch.)
4L SW [ON/OFF]×–×4WD shift switch status is displayed.
(4L means 4LO of 4WD shift switch.)
N POSI SW TF [ON/OFF]×–×Neutral-4LO switch signal status is displayed.
ATP SWITCH [ON/OFF]×–×ATP switch signal status is displayed.
WAIT DETCT SW [ON/OFF]×–×Wait detection switch status is displayed.
LINE PRES SW [ON/OFF]×–×Line pressure switch status is displayed.
CL PRES SW [ON / OFF]×–×Clutch pressure switch status is displayed.
N POSI SW AT [ON/OFF]זדN” position signal of A/T PNP switch status is
displayed.
Signal input with CAN communication line.
R POSI SW AT [ON/OFF]זדR” position signal of A/T PNP switch status is
displayed.
Signal input with CAN communication line.
P POSI SW AT [ON/OFF]זדP” position signal of A/T PNP switch status is
displayed.
Signal input with CAN communication line.
ABS OPER SW [ON/OFF]×–×ABS operation signal status is displayed.
Signal input with CAN communication line.
VDC OPER SW [ON/OFF]×–×VDC operation signal status is displayed.
Signal input with CAN communication line.
TCS OPER SW [ON/OFF]×–×TCS operation signal status is displayed.
Signal input with CAN communication line.

TF-46
< SERVICE INFORMATION >
TROUBLE DIAGNOSIS
THROTTLE POSI [0.0/8] –××Thottle position status is displayed.
Signal input with CAN communication line.
4WD MODE [AUTO/LOCK/2WD/4L] –××Control status of 4WD recognized by transfer
control unit. (AUTO, 4H, 2WD or 4LO)
VHCL/S COMP [km/h] or [mph] –××Vehicle speed recognized by transfer control
unit.
COMP CL TORQ [kgm] –××Calculated torque recognized by transfer con-
trol unit.
DUTY SOLENOID [%] –××Control value of clutch pressure solenoid.
2-4WD SOL [ON/OFF] –××Output condition to 2-4WD solenoid.
2-4WD SOL MON [ON/OFF] – –×Check signal for transfer control unit signal
output.
MOTOR RELAY [ON/OFF] –××Transfer motor relay signal status is dis-
played.
MOTOR RELAY MON [ON/OFF] – –×Check signal for transfer control unit signal
output.
4WD FAIL LAMP [ON/OFF] –××Control status of 4WD warning lamp is dis-
played.
2WD IND [ON/OFF] – –×Control status of 4WD shift indicator lamp
(2WD indicator lamp) is displayed.
AUTO IND [ON/OFF] – –×Control status of 4WD shift indicator lamp
(2WD and AUTO indicator lamp) is displayed.
LOCK IND [ON/OFF] – –×Control status of 4WD shift indicator lamp
(2WD, AUTO and Lock indicator) is displayed.
4L IND [ON/OFF] – –×Control status of 4LO indicator lamp is dis-
played.
ATP IND [ON/OFF] – –×Control status of ATP warning lamp is dis-
played.
SHIFT POS SW1 [ON/OFF]×–×Actuator position switch 1 (Low) signal status
is displayed.
SHIFT POS SW2 [ON/OFF]×–×Actuator position switch 2 (high) signal status
is displayed.
SHIFT ACT1 [ON/OFF] –××Output condition to actuator motor (clockwise)
SHIFT AC MON1 [ON/OFF]×–×Check signal for transfer control unit signal
output
SHIFT ACT2 [ON/OFF] –××Output condition to actuator motor (counter-
clockwise)
SHIFT AC MON2 [ON/OFF]×–×Check signal for transfer control unit signal
output
T/F F SPEED [km/h] or [mph]×–×Displayed, but do not use.
A/T R SPEED [km/h] or [mph]×–×Output shaft revolution signal (Revolution
sensor) calculated by TCM.
Signal input with CAN communication line.
AT GEAR POSI [1/2/3/4/5]
×–×A/T actual gear position is displayed.
Voltage [V] – –×The value measured by the voltage probe is
displayed. Monitored item (Unit)Monitor item selection
Remarks
ECU INPUT
SIGNALSMAIN
SIGNALSSELEC-
TION FROM
MENU

TROUBLE DIAGNOSIS
TF-47
< SERVICE INFORMATION >
C
E
F
G
H
I
J
K
L
MA
B
TF
N
O
PWORK SUPPORT
When there is no problem with transfer and 4WD system, following symptom in “AUTO” mode may be claimed
by a customer.
• Vibration when accelerating on a low µ road (snow-covered or icy road)
It is possible to deal with these symptoms by changing “CLUTCH FORCE RELEASE LIMIT VALUE”. How-
ever, be careful when changing the values because it may adversely affect driving performance.
NOTE:
A slight shock is felt at a few hertz as if it were being pushed lightly from behind.
Operation Procedure
1. Refer to GI-36, "CONSULT-II Start Procedure".
2. Select “CLUTCH/F RLS LIM ADJ”.
Clutch Force Release Limit Adjustment
1. Current CLUTCH FORCE RELEASE LIMIT value “0.3 kgm”
appears under “CONDITION SETTING” on CONSULT-II display.
2. Touch “1.2” on the display.
3. Display changes to “NOW ADJUSTING” in a short time.
Frequency [Hz] – –×
The value measured by the pulse probe is dis-
played. DUTY-HI (high) [%] – –×
DUTY-LOW (low) [%] – –×
PLS WIDTH-HI [msec] – –×
PLS WIDTH-LOW [msec] – –× Monitored item (Unit)Monitor item selection
Remarks
ECU INPUT
SIGNALSMAIN
SIGNALSSELEC-
TION FROM
MENU
1.2 kg-m : Tight corner braking symptom is alleviated.
However, vibration may occur when acceler-
ating on a low µ road (icy road, etc.).
0.3 kg-m : Initial set value.
0.2 kg-m : Do not set to this value because the tight
corner braking symptom will get worse.
SMT968D
SMT969D

TF-144
< SERVICE INFORMATION >
TRANSFER ASSEMBLY
d. Place the control valve with the lower body facing up. Remove
the two bolts, and then remove the lower body and separator
plate from the upper body.
CAUTION:
Do not drop relief balls. Detach lower body carefully.
e. Make sure the reverse balls, relief balls, relief springs, accumu-
lator pistons and valve springs are securely installed as shown,
and remove them.
f. Remove the retainer plates.
g. Remove each control valve, spring and plug.
37. Remove the transfer motor bolts and motor from the center
case. Then remove the O-ring from the transfer motor.
SDIA3187E
SDIA2126E
SDIA2127E
SDIA3317E
SDIA2133E

TF-152
< SERVICE INFORMATION >
TRANSFER ASSEMBLY
f. With the lower body down, tighten the two bolts shown.
g. Apply ATF to the new O-rings, and install them to each solenoid
valve, switch and terminal body.
CAUTION:
Do not reuse O-rings.
h. Install the following to the control valve assembly:
• Clutch pressure solenoid valve
• 2-4WD shift solenoid valve
• Clutch pressure switch
• Line pressure switch
• Transfer fluid temperature sensor
10. Apply ATF to the new lip seals, and install them to the center
case.
CAUTION:
• Do not reuse lip seals.
• There are 2 kinds of lip seals (lip seal of large inner diam-
eter: 5 pieces, lip seal of small inner diameter: 2 pieces).
Confirm their position for installation.
11. Install the control valve assembly to the center case, and tighten
to the specified torque. Refer to TF-128, "
Disassembly and
Assembly".
CAUTION:
• Do not reuse any part that has been dropped or damaged.
• Make sure valve is assembled in the proper direction.
• Do not use a magnet because residual magnetism stays
during assembly.
12. Install the connector assembly into the center case, and secure
with a snap ring.
13. Apply ATF to the new O-rings, and install them on the oil
strainer.
CAUTION:
Do not reuse O-rings.
14. Install the oil strainer to the control valve assembly.
WDIA0198E
SDIA2123E
SDIA2121E
SDIA2122E
SDIA2782E

TF-156
< SERVICE INFORMATION >
TRANSFER ASSEMBLY
30. Install the new snap ring to the main shaft.
CAUTION:
Do not reuse snap ring.
31. Install the mainshaft rear bearing to the center case using Tool.
32. Press the mainshaft assembly into the center case using Tools.
33. Install the C-rings to the mainshaft.
34. Set the washer holder on the mainshaft, and secure it with a
new snap ring using suitable tool.
CAUTION:
Do not reuse snap ring.
SDIA2195E
Tool number : ST15310000 (J-25640-B)
SDIA2196E
Tool number A: ST30911000 ( — )
B: ST33052000 ( — )
SDIA2197E
SDIA2201E
SDIA2104E

TF-160
< SERVICE INFORMATION >
TRANSFER ASSEMBLY
5. Install the sun gear assembly to the planetary carrier assembly.
6. Install the new snap ring to the planetary carrier assembly.
CAUTION:
Do not reuse snap ring.
7. Set the input bearing into the front case and install using Tool.
8. Install the new snap ring into the front case.
CAUTION:
Do not reuse snap ring.
9. Install the internal gear with its groove facing the new snap ring
into the front case. Then secure it with the new snap ring.
CAUTION:
Do not reuse snap ring.
SDIA2180E
SDIA2181E
Tool number : ST30720000 (J-25405)
SDIA2172E
SDIA2171E
WDIA0100E