2008 INFINITI QX56 oil change

SEC-98
< ECU DIAGNOSIS >[WITH INTELLIGENT KEY SYSTEM]
IPDM E/R (INTELLIGENT POWER DI
STRIBUTION MODULE ENGINE ROOM)
IPDM E/R (INTELLIGENT POWER DISTRIBUTION MODULE ENGINE
ROOM)
Reference ValueINFOID:0000000004807922
VALUES ON THE DIAGNOSIS TOOL
Monitor Item ConditionValue/Status
MOTOR FAN REQ Engine idle speed Changes depending on engine
coolant temperature, air conditioner
operation status, vehicle speed,
etc.0 - 100 %
A/C COMP REQ A/C switch OFF
OFF
A/C switch ON ON
TAIL&CLR REQ Lighting switch OFF
OFF
Lighting switch 1ST, 2ND, HI or AUTO (Light is illuminated) ON
HL LO REQ Lighting switch OFF
OFF
Lighting switch 2ND HI or AUTO (Light is illuminated) ON
HL HI REQ Lighting switch OFF
OFF
Lighting switch HI ON
FR FOG REQ Lighting switch 2ND or AUTO (Light
is illuminated) Front fog lamp switch OFF OFF
• Front fog lamp switch ON
• Daytime light activated (Canada
only) ON
HL WASHER REQ NOTE:
This item is displayed, but cannot be monitored.
OFF
FR WIP REQ Ignition switch ON Front wiper switch OFF
STOP
Front wiper switch INT 1LOW
Front wiper switch LO LOW
Front wiper switch HI HI
WIP AUTO STOP Ignition switch ON Front wiper stop position
STOP P
Any position other than front wiper
stop position ACT P
WIP PROT Ignition switch ON Front wiper operates normally OFF
Front wiper stops at fail-safe opera-
tion
BLOCK
ST RLY REQ Ignition switch OFF or ACC
OFF
Ignition switch START ON
IGN RLY Ignition switch OFF or ACC
OFF
Ignition switch ON ON
RR DEF REQ Rear defogger switch OFF
OFF
Rear defogger switch ON ON
OIL P SW Ignition switch OFF, ACC or engine running
OPEN
Ignition switch ON CLOSE
DTRL REQ Daytime light system requested OFF with CONSULT-III.
OFF
Daytime light system requested ON with CONSULT-III. ON
HOOD SW Hood closed.
OFF
Hood open. ON
Revision: March 2010 2008 QX56

IPDM E/R (INTELLIGENT POWER DISTRIBUTION MODULE ENGINE ROOM)
SEC-109
< ECU DIAGNOSIS > [WITH INTELLIGENT KEY SYSTEM]
C
D
E
F
G H
I
J
L
M A
B
SEC
N
O P
If No CAN Communication Is Available With BCM
IGNITION RELAY MALFUNCTION DETECTION FUNCTION
• IPDM E/R monitors the voltage at the contact circuit and excitation coil circuit of the ignition relay inside it.
• IPDM E/R judges the ignition relay error if the voltage differs between the contact circuit and the excitation
coil circuit.
• If the ignition relay cannot turn OFF due to contact seizure, it activates the tail lamp relay for 10 minutes to alert the user to the ignition relay malfunction when the ignition switch is turned OFF.
NOTE:
The tail lamp turns OFF when the ignition switch is turned ON.
FRONT WIPER CONTROL
IPDM E/R detects front wiper stop posit ion by a front wiper auto stop signal.
When a front wiper auto stop signal is in the conditions listed below, IPDM E/R stops power supply to wiper
after repeating a front wiper 10 second activation and 20 second stop five times.
NOTE:
This operation status can be confirmed on the IPDM E/R “DATA MONITOR” that displays “Block” for the item
“WIP PROT” while the wiper is stopped.
STARTER MOTOR PROTECTION FUNCTION
IPDM E/R turns OFF the starter control relay to protect the starter motor when the starter control relay remains
active for 90 seconds.
Control part Fail-safe in operation
Cooling fan • Turns ON the cooling fan relay when the ignition switch is turned ON
• Turns OFF the cooling fan relay when the ignition switch is turned OFF
Control part
Fail-safe in operation
Headlamp • Turns ON the headlamp low relay when the ignition switch is turned ON
• Turns OFF the headlamp low relay when the ignition switch is turned OFF
• Headlamp high relay OFF
•Parking lamps
• License plate lamps
• Tail lamps • Turns ON the tail lamp relay when the ignition switch is turned ON
• Turns OFF the tail lamp relay when the ignition switch is turned OFF
Front wiper • The status just before activation of fail-safe control is maintained until the ignition
switch is turned OFF while the front wiper is operating at LO or HI speed.
• The wiper is operated at LO speed until the ignition switch is turned OFF if the fail- safe control is activated while the front wipe r is set in the INT mode and the front wiper
motor is operating.
Rear window defogger Rear window defogger relay OFF
A/C compressor A/C relay OFF
Front fog lamps Front fog lamp relay OFF
Ignition switch Ignition relayTail lamp relay
ON ON —
OFF OFF —
Ignition switchFront wiper switch Auto stop signal
ON OFF
Front wiper stop position signal cannot be
input 10 seconds.
ON The signal does not change for 10 seconds.
Revision: March 2010 2008 QX56

POWER STEERING GEAR AND LINKAGEST-31
< DISASSEMBLY AND ASSEMBLY >
C
DE
F
H I
J
K L
M A
B
ST
N
O P
POWER STEERING GEAR AND LINKAGE
Disassembly and AssemblyINFOID:0000000004920105
CAUTION:
• Secure steering gear assembly with a vise, using copper plates or something similar to prevent it
from being damaged. Do not grip cylinder with a vise.
• Before performing disassembly, clean steering gear assembly with kerosene. Be careful not to bring
any kerosene into contact with the di scharge and return port connectors.
DISASSEMBLY
1. Remove cylinder tubes from gear housing assembly.
2. Loosen lock nuts of outer sockets, and remove outer sockets.
3. Remove boot clamps of the small diameter si de and the large diameter side, then remove boot.
CAUTION:
When removing boots, be careful not to damage inner socket and gear housing assembly. If they
are damaged, change th em to avoid oil leaks.
4. Remove inner sockets.
INSPECTION AFTER DISASSEMBLY
Boot
Check boot for tears, cracks and deformation. Replace if necessary.
1. Boot clamp 2. Inner socket3. Boot
4. Boot clamp 5. Outer socket6. Cylinder tubes
7. Gear housing assembly 8. Connector
AWGIA0087GB
Revision: March 2010 2008 QX56

A/T CONTROL SYSTEMTM-23
< FUNCTION DIAGNOSIS >
CEF
G H
I
J
K L
M A
B
TM
N
O P
• This line pressure solenoid controls the pressure regulat or valve as the signal pressure and adjusts the pres-
sure of the operating oil discharged from the oil pump to the line pressure most appropriate to the driving
state.
LINE PRESSURE CONTROL IS BASED ON THE TCM LINE PRESSURE CHARACTERISTIC PAT-
TERN
• The TCM has stored in memory a number of patterns fo r the optimum line pressure characteristic for the
driving state.
• In order to obtain the most appropriate line pressure char acteristic to meet the current driving state, the TCM
controls the line pressure solenoid current value and thus controls the line pressure.
Normal Control
Each clutch is adjusted to the necessary pressure to match the
engine drive force.
Back-up Control (Engine Brake)
When the select operation is performed during driving and the trans-
mission is shifted down, the line pressure is set according to the
vehicle speed.
During Shift Change
PCIA0007E
PCIA0008E
PCIA0009E
Revision: March 2010 2008 QX56

TM-24
< FUNCTION DIAGNOSIS >
A/T CONTROL SYSTEM
The necessary and adequate line pressure for shift change is set.
For this reason, line pressure pattern setting corresponds to input
torque and gearshift selection. Also, line pressure characteristic is
set according to engine speed, during engine brake operation.
At Low Fluid Temperature
When the A/T fluid temperature drops below the prescribed tempera-
ture, in order to speed up the action of each friction element, the line
pressure is set higher than the normal line pressure characteristic.
Shift ControlINFOID:0000000001603994
The clutch pressure control solenoid is controlled by the signals from the switches and sensors. Thus, the
clutch pressure is adjusted to be appropriate to the engine load state and vehicle driving state. It becomes
possible to finely control the clutch hydraulic pressure with high precision and a smoother shift change charac-
teristic is attained.
SHIFT CHANGE
The clutch is controlled with the optimum timing and oil pressure by the engine speed, engine torque informa-
tion, etc.
Shift Change System Diagram
PCIA0010E
PCIA0011E
PCIA0012E
Revision: March 2010 2008 QX56

A/T CONTROL SYSTEMTM-25
< FUNCTION DIAGNOSIS >
CEF
G H
I
J
K L
M A
B
TM
N
O P
*1: Full phase real-time feedback control monitors move ment of gear ratio at gear change, and controls oil
pressure at real-time to achieve the best gear ratio.
Lock-up ControlINFOID:0000000001603995
The torque converter clutch piston in the torque conv erter is engaged to eliminate torque converter slip to
increase power transmission efficiency.
The torque converter clutch control valve operation is controlled by the torque conver ter clutch solenoid valve,
which is controlled by a signal from TCM, and the torque converter clutch control valve engages or releases
the torque converter clutch piston.
Lock-up Operation Condition Table
TORQUE CONVERTER CLUTCH CONTROL VALVE CONTROL
Lock-up Control System Diagram
Lock-up Released
• In the lock-up released state, the torque converter clutch control valve is set into the unlocked state by the
torque converter clutch solenoid and the lock-up apply pressure is drained.
In this way, the torque converter clutch piston is not coupled.
Lock-up Applied
• In the lock-up applied state, the torque converter clutch control valve is set into the locked state by the
torque converter clutch solenoid and lock-up apply pressure is generated.
In this way, the torque converter clutch piston is pressed and coupled.
SMOOTH LOCK-UP CONTROL
PCIA0013E
Select lever D position4 position 3 position 2 position
G ear p osit io n 54432
Lock-up ×– ×××
Slip lock-up ××–––
PCIA0014E
Revision: March 2010 2008 QX56

A/T CONTROL SYSTEMTM-27
< FUNCTION DIAGNOSIS >
CEF
G H
I
J
K L
M A
B
TM
N
O P
FUNCTION OF PRESSURE SWITCH
Pilot valve A Adjusts the line pressure and produces the constant pressure (pilot pressure) required
for line pressure control, shift change control, and lock-up control.
Pilot valve B Adjusts the line pressure and produces the constant pressure (pilot pressure) required
for shift change control.
Low coast brake switching valve During engine braking, supplies the line pressure to the low coast brake reducing valve.
Low coast brake reducing valve When the low coast brake is coupled, adjusts the line pressure to the optimum pressure
(low coast brake pressure) and supplies it to the low coast brake.
N-R accumulator Produces the stabilizing pressure for when N-R is selected.
Direct clutch piston switching valve Operates in 4GR gear and switches the direct clutch coupling capacity.
High and low reverse clutch control valve When the high and low reverse clutch is coupled, adjusts the line pressure to the opti-
mum pressure (high and low reverse clutch pressure) and supplies it to the high and low
reverse clutch. (In 1GR, 3GR, 4GR and 5GR, adjusts the clutch pressure.)
Input clutch control valve When the input clutch is coupled, adjusts the line pressure to the optimum pressure (in-
put clutch pressure) and supplies it to the input clutch. (In 4GR and 5GR, adjusts the
clutch pressure.)
Direct clutch control valve When the direct clutch is coupled, adjusts the line pressure to the optimum pressure (di-
rect clutch pressure) and supplies it to the direct clutch. (In 2GR, 3GR, and 4GR, adjusts
the clutch pressure.)
TCC control valve
TCC control plug
TCC control sleeve Switches the lock-up to operating or released. Also, by performing the lock-up operation
transiently, lock-up smoothly.
Torque converter lubrication valve Operates during lock-up to switch the torque converter, cooling, and lubrication system
oil path.
Cool bypass valve Allows excess oil to bypass cooler circuit without being fed into it.
Line pressure relief valve Discharges excess oil from line pressure circuit.
N-D accumulator Produces the stabilizing pressure for when N-D is selected.
Manual valve Sends line pressure to each circuit according to the select position. The circuits to which
the line pressure is not sent drain.
Name
Function
Name Function
Pressure switch 2 (LC/B) Detects any malfunction in the low coast brake hydraulic pressure. When it detects any
malfunction, it puts the system into fail-safe mode.
Revision: March 2010
2008 QX56

TM-160
< SYMPTOM DIAGNOSIS >
SYSTEM SYMPTOM
25Slips/Will
Not en-
gage Does not hold lock-up
condition.
Refer to TM-139, "A/T
Does Not Hold Lock-
up Condition".
ON vehicle 1. Fluid level and state
TM-178
2. Line pressure testTM-187
3. Engine speed signal TM-51
4. Input speed sensorTM-46
5. Torque converter clutch solenoid valveTM-63
6. CAN communication line LAN-4
7. Control valve with TCMTM-201
OFF vehicle8. Torque converter
TM-2329. Oil pump assemblyTM-250
26Lock-up is not re-
leased.
Refer to TM-140,
"Lock-up Is Not Re-
leased".ON vehicle1. Fluid level and state
TM-178
2. Line pressure testTM-187
3. Engine speed signal TM-51
4. Input speed sensorTM-46
5. Torque converter clutch solenoid valveTM-63
6. CAN communication line LAN-4
7. Control valve with TCMTM-201
OFF vehicle8. Torque converter
TM-2329. Oil pump assemblyTM-250
27No shock at all or the
clutch slips when vehi-
cle changes speed D1
→ D2. ON vehicle
1. Fluid level and state
TM-178
2. Output speed sensor and vehicle speed sensor TM-48,
TM-74
3. Direct clutch solenoid valve TM-84
4. CAN communication line LAN-4
5. Line pressure testTM-187
6. Control valve with TCMTM-201
OFF vehicle7. Torque converter
TM-232
8. Oil pump assemblyTM-250
9. 3rd one-way clutchTM-252
10. Gear systemTM-220
11. Direct clutchTM-266
12. Forward brake (Parts behind drum support is impossible
to perform inspection by disassembly. Refer to TM-8
, TM-9TM-232
No. Items Symptom Condition Diagnostic ItemReference
page
Revision: March 2010 2008 QX56