2010 INFINITI QX56 torque

TM-66
< COMPONENT DIAGNOSIS >
P0740 TORQUE CONVERTER
3. Start engine.
4. Read out the value of “TCC SOLENOID” while driving.
OK or NG
OK >> GO TO 4.
NG >> GO TO 2.
2.CHECK TCM POWER SUPPLY AND GROUND CIRCUIT
Check TCM power supply and ground circuit. Refer to TM-94, "
Diagnosis Procedure".
OK or NG
OK >> GO TO 3.
NG >> Repair or replace damaged parts.
3.DETECT MALFUNCTIONING ITEM
Check the following items:
• The A/T assembly harness connector pin terminals for damage or loose connection with harness connector.
OK or NG
OK >> Replace the control valve with TCM. Refer to TM-172, "Control Valve with TCM and A/T Fluid
Temperature Sensor 2 and Plug".
NG >> Repair or replace damaged parts.
4.CHECK DTC
Perform “DTC Confirmation Procedure”.
• Refer to TM-65, "
DTC Confirmation Procedure".
OK or NG
OK >> INSPECTION END
NG >> GO TO 2.
Item name Condition Display value (Approx.)
TCC SOLENOID When performing slip lock-up.
0.2 - 0.4 A
When performing lock-up. 0.4 - 0.6 A
Revision: April 20092010 QX56

P0744 TORQUE CONVERTERTM-67
< COMPONENT DIAGNOSIS >
CEF
G H
I
J
K L
M A
B
TM
N
O P
P0744 TORQUE CONVERTER
DescriptionINFOID:0000000005148599
This malfunction is detected when the A/T does not lock-up. This is not only caused by electrical malfunction
(circuits open or shorted) but also by mechanical malfunc tion such as control valve sticking, improper solenoid
valve operation, etc.
CONSULT-III Reference Val ue in Data Monitor ModeINFOID:0000000005148600
On Board Diagnosis LogicINFOID:0000000005148601
• This is an OBD-II self-diagnostic item.
• Diagnostic trouble code “P0744 TORQUE CONVERTER” wi th CONSULT-III is detected under the following
conditions.
- When A/T cannot perform lock-up even if electrical circuit is good.
- When TCM detects as irregular by comparing difference value with slip rotation.
Possible CauseINFOID:0000000005148602
• Harness or connectors (The solenoid circuit is open or shorted.)
• Torque converter clutch solenoid valve
• Hydraulic control circuit
DTC Confirmation ProcedureINFOID:0000000005148603
CAUTION:
Always drive vehicle at a safe speed.
NOTE:
If “DTC Confirmation Procedure” has been previously performed, always turn ignition switch “OFF”
and wait at least 10 seconds before performing the next test.
After the repair, perform the following procedure to confirm the malfunction is eliminated.
WITH CONSULT-III
1. Start engine and Select “TCC S/V FNCTN CHECK” of “DTC WORK SUPPORT” mode for “TRANSMIS- SION” with CONSULT-III and touch “START”.
2. Accelerate vehicle to more than 80 km/h (50 MPH) and maintain the following condition continuously until “TESTING” has turned to “COMPLETE”. (It will take approximately 30 seconds after “TESTING” shows.)
ACCELE POSI: More than 1.0/8 (at all times during step 4)
TCC SOLENOID: 0.4 - 0.6 A
SLCT LVR POSI: “D” position
[Reference speed: Constant speed of more than 80 km/h (50 MPH)]
- Make sure “GEAR” shows “5”.
- For shift schedule, refer to TM-266, "
Vehicle Speed at Which Lock-up Occurs/Releases".
- If “TESTING” does not appear on CONSULT-III for a long time, select “SELF-DIAG RESULTS”. In
case a 1st trip DTC other than P0744 is shown, refer to applicable “TROUBLE DIAGNOSIS FOR
DTC”.
3. Make sure that “OK” is disp layed. (If “NG” is displayed, refer to “DIAGNOSTIC PROCEDURE”.)
Refer to TM-68, "
Diagnosis Procedure".
Refer to shift schedule, TM-266, "
Vehicle Speed at Which Lock-up Occurs/Releases".
WITH GST
Follow the procedure “With CONSULT-III”.
Item name Condition Display value (Approx.)
TCC SOLENOID When performing slip lock-up.
0.2 - 0.4 A
When performing lock-up. 0.4 - 0.6 A
Revision: April 20092010 QX56

TM-68
< COMPONENT DIAGNOSIS >
P0744 TORQUE CONVERTER
Diagnosis Procedure
INFOID:0000000005148604
1.CHECK INPUT SIGNAL
With CONSULT-III
1. Turn ignition switch “ON”.
2. Select “MAIN SIGNALS” in “DATA MONITO R” mode for “TRANSMISSION” with CONSULT-III.
3. Start the engine.
4. Read out the value of “TCC SOLENOID” while driving.
OK or NG
OK >> GO TO 4.
NG >> GO TO 2.
2.CHECK TCM POWER SUPPLY AND GROUND CIRCUIT
Check TCM power supply and ground circuit. Refer to TM-94, "
Diagnosis Procedure".
OK or NG
OK >> GO TO 3.
NG >> Repair or replace damaged parts.
3.DETECT MALFUNCTIONING ITEM
Check the following items:
• The A/T assembly harness connector pin terminals for damage or loose connection with harness connector.
OK or NG
OK >> Replace the control valve with TCM. Refer to TM-172, "Control Valve with TCM and A/T Fluid
Temperature Sensor 2 and Plug".
NG >> Repair or replace damaged parts.
4.CHECK DTC
Perform “DTC Confirmation Procedure”.
• Refer to TM-67, "
DTC Confirmation Procedure".
OK or NG
OK >> INSPECTION END
NG >> GO TO 2.
Item name Condition Display value (Approx.)
TCC SOLENOID When performing slip lock-up.
0.2 - 0.4 A
When performing lock-up. 0.4 - 0.6 A
Revision: April 20092010 QX56

TM-118
< ECU DIAGNOSIS >
TCM
Even when the electronic circuits are normal, under special conditions (for example, when slamming on the
brake with the wheels spinning drastically and stopping the tire rotation), the transmission can go into fail-safe
mode. If this happens, switch “OFF” the ignition switch for 10 seconds, then switch it “ON” again to return to
the normal shift pattern. Therefore, the customer's v ehicle has returned to normal, so handle according to the
“diagnostics flow” (Refer to TM-5, "
Work Flow").
FAIL-SAFE FUNCTION
If any malfunction occurs in a sensor or solenoid, th is function controls the A/T to mark driving possible.
Output Speed Sensor
• Signals are input from two systems - from output speed sensor installed on the transmission and from com-
bination meter so normal driving is possible even if there is a malfunction in one of the systems. And if output
speed sensor has unusual cases, 5GR is prohibited.
Accelerator Peda l Position Sensor
• If there is a malfunction in one of the systems, the accelerator opening angle is controlled by ECM according
to a pre-determined accelerator angle to make driving possible. And if there are malfunctions in tow sys-
tems, the engine speed is fixed by ECM to a pre-determined engine speed to make driving possible.
Throttle Position Sensor
• If there is a malfunction in one of the systems, the accelerator opening angle is controlled by ECM according
to a pre-determined accelerator angle to make driving possible. And if there are malfunctions in tow sys-
tems, the accelerator opening angle is controlled by the idle signal sent from the ECM which is based on
input indicating either idle condition or off-idle condition (pre-determined accelerator opening) in order to
make driving possible.
Transmission Range Switch
• In the unlikely event that a malfunction signal enters t he TCM, the position indicator is switched “OFF”, the
starter relay is switched “OFF” (starter starting is disabled), the back-up lamp relay switched “OFF” (back-up
lamp is OFF) and the position is fixed to the “D” position to make driving possible.
Starter Relay
• The starter relay is switched “OFF”. (Starter starting is disabled.)
Interlock
• If there is an interlock judgment malfunction, the trans mission is fixed in 2GR to make driving possible.
NOTE:
When the vehicle is driven fixed in 2GR, a input speed sensor malfunction is displayed, but this is
not a input speed sensor malfunction.
• When the interlock is detected at the 3GR or more, it is locked at the 2GR.
1st Engine Braking
• When there is an 1st engine brake judgment malfunction, the low coast brake solenoid is switched “OFF” to
avoid the engine brake operation.
Line Pressure Solenoid
• The solenoid is switched “OFF” and the line pressure is set to the maximum hydraulic pressure to make driv- ing possible.
Torque Converter Clutch Solenoid
• The solenoid is switched “OFF” to release the lock-up.
Low Coast Brake Solenoid
• When a (electrical or functional) malfunction occurs, in order to make driving possible, the engine brake isnot applied in 1GR and 2GR.
Input Clutch Solenoid
• If a (electrical or functional) malfunction occurs with the solenoid either “ON” or “OFF”, the transmission is
held in 4GR to make driving possible.
Direct Clutch Solenoid
• If a (electrical or functional) malfunction occurs with the solenoid either “ON” or “OFF”, the transmission is
held in 4GR to make driving possible.
Front Brake Solenoid
• If a (electrical or functional) malfunction occurs with the solenoid “ON”, in order to make driving possible, the
A/T is held in 5GR; if the solenoid is OFF, 4GR.
Revision: April 20092010 QX56

TCM
TM-119
< ECU DIAGNOSIS >
C EF
G H
I
J
K L
M A
B
TM
N
O P
High and Low Revers
e Clutch Solenoid
• If a (electrical or functional) malfunction occurs with the solenoid either “ON” or “OFF”, the transmission is
held in 4GR to make driving possible.
Input Speed Sensor 1 or 2
• The control is the same as if there were no input speed sensors, 5GR is prohibited.
DTC Inspection Priority ChartINFOID:0000000005148691
If some DTCs are displayed at the same time, perform inspections one by one based on the following priority
chart.
NOTE:
If DTC U1000 is displayed with other DTCs, first pe rform the trouble diagnosis for DTC U1000. Refer to
TM-40, "
Diagnosis Procedure".
DTC No. IndexINFOID:0000000005148692
NOTE:
If DTC U1000 is displayed with other DTC, first pe rform the trouble diagnosis for DTC U1000. Refer to
TM-40, "
Diagnosis Procedure".
Priority Detected items (DTC)
1 U1000 CAN COMM CIRCUIT
2 Except above
DTC
Items
(CONSULT- III screen terms) Reference
OBD- II
Except OBD- II
CONSULT- III GST (*1) CONSULT- III only
“TRANSMISSION”
— P0615STARTER RELAY TM-41
P0700P0700TRANSMISSION CONTROL TM-44
P0705P0705T/M RANGE SWITCH A TM-45
P0710P1710FLUID TEMP SENSOR TM-73
P0717P0717INPUT SPEED SENSOR A TM-48
P0720P0720OUTPUT SPEED SENSOR TM-51
—P0725ENGINE SPEED TM-53
P0731P07311GR INCORRECT RATIO TM-56
P0732P07322GR INCORRECT RATIO TM-58
P0733P07333GR INCORRECT RATIO TM-60
P0734P07344GR INCORRECT RATIO TM-62
P0735P07355GR INCORRECT RATIO TM-64
P0740P0740TORQUE CONVERTER TM-65
P0744 P0744 TORQUE CONVERTER TM-68
P0745P0745PC SOLENOID A TM-69
—P1705TP SENSOR TM-71
—P1721VEHICLE SPEED SIGNAL TM-76
P1730P1730INTERLOCK TM-78
—P17311GR E/BRAKING TM-80
P1752P1752INPUT CLUTCH SOLENOID TM-82
P1757P1757FR BRAKE SOLENOID TM-84
P1762P1762DRCT CLUTCH SOLENOID TM-86
P1767P1767HLR CLUTCH SOLENOID TM-88
Revision: April 20092010 QX56

TM-120
< ECU DIAGNOSIS >
TCM
*1: These numbers are prescribed by SAE J2012.
*2: These malfunctions cannot be displayed MIL if another malfunction is assigned to MIL.
DTC Alphabetical IndexINFOID:0000000005148693
NOTE:
If DTC U1000 is displayed with other DTC, first perform the trouble diagnosis for DTC U1000. Refer to
TM-40, "
Diagnosis Procedure".
*1: These numbers are prescribed by SAE J2012.
*2: These malfunctions cannot be displayed MIL if another malfunction is assigned to MIL. P1772
P1772L C BRAKE SOLENOID TM-90
P1774 (2*) P1774 L C BRAKE SOLENOID TM-93
U1000U1000CAN COMM CIRCUIT TM-40
DTC
Items
(CONSULT- III screen terms) Reference
OBD- II
Except OBD- II
CONSULT- III GST (*1) CONSULT- III only
“TRANSMISSION”
Items
(CONSULT- III screen terms) DTC
Reference
OBD- II
Except OBD- II
CONSULT- III GST (*1) CONSULT- III only “TRANS-
MISSION”
1ST E/BRAKING —P1731TM-80
1GR INCORRECT RATIO P0731P0731TM-56
2GR INCORRECT RATIO P0732P0732TM-58
3GR INCORRECT RATIO P0733P0733TM-60
4GR INCORRECT RATIO P0734P0734TM-62
5GR INCORRECT RATIO P0735P0735TM-64
INTERLOCK P1730P1730TM-78
TORQUE CONVERTER P0744 P0744 TM-68
FLUID TEMP SENSOR P0710P1710TM-73
CAN COMM CIRCUIT U1000U1000TM-40
DRCT CLUTCH SOLENOID P1762P1762 TM-86
ENGINE SPEED —P0725TM-53
FR BRAKE SOLENOID P1757P1757TM-84
HLR CLUTCH SOLENOID P1767P1767TM-88
INPUT CLUTCH SOLENOID P1752P1752TM-82
PC SOLENOID A P0745P0745TM-69
L C BRAKE SOLENOID P1772P1772TM-90
L C BRAKE SOLENOID P1774 P1774 TM-93
T/M RANGE SWITCH A P0705P0705TM-45
STARTER RELAY —P0615TM-41
TORQUE CONVERTER P0740P0740TM-65
TRANSMISSION CONTROL P0700P0700TM-44
TP SENSOR —P1705TM-71
INPUT SPEED SENSOR A P0717P0717TM-48
VEHICLE SPEED SIGNAL —P1721TM-76
OUTPUT SPEED SENSOR P0720P0720TM-51
Revision: April 20092010 QX56

SYSTEM SYMPTOMTM-123
< SYMPTOM DIAGNOSIS >
CEF
G H
I
J
K L
M A
B
TM
N
O P
7
Shift
Shock Shock is too large for
upshift when accelera-
tor pedal is released.
ON vehicle1. Accelerator pedal position sensor
TM-71
2. Control cable adjustmentTM-164
3. Engine speed signal TM-53
4. CAN communication line LAN-4
5. Input speed sensorInput speed sensorTM-48
6. Output speed sensor and vehicle speed signalTM-50,
TM-76
7. Fluid level and state TM-148
8. Control valve with TCMTM-172
OFF vehicle9. Front brake (brake band)
TM-19210. Input clutchTM-227
11. High and low reverse clutchTM-237
12. Direct clutchTM-239
8Shock is too large for
lock-up. ON vehicle1. Accelerator pedal position sensor
TM-71
2. Control cable adjustmentTM-164
3. Engine speed signal TM-53
4. CAN communication line LAN-4
5. Input speed sensorTM-48
6. Output speed sensor and vehicle speed signalTM-50,
TM-76
7. Torque converter clutch solenoid valve TM-65
8. Fluid level and stateTM-148
9. Control valve with TCMTM-172
OFF vehicle 10. Torque converter TM-172
9Shock is too large dur-
ing engine brake. ON vehicle
1. Accelerator pedal position sensor
TM-71
2. Control cable adjustmentTM-164
3. CAN communication line LAN-4
4. Fluid level and stateTM-148
5. Control valve with TCMTM-172
OFF vehicle6. Front brake (brake band)
TM-1727. Input clutchTM-172
8. High and low reverse clutchTM-172
9. Direct clutchTM-172
No. ItemsSymptom Condition Diagnostic ItemReference
page
Revision: April 20092010 QX56

TM-128
< SYMPTOM DIAGNOSIS >
SYSTEM SYMPTOM
22Slips/Will
Not En-
gage When “D” position, re-
mains in 5GR.
ON vehicle1. Fluid level and state
TM-148
2. Output speed sensor and vehicle speed signal TM-50,
TM-76
3. Front brake solenoid valve TM-84
4. Line pressure testTM-157
5. CAN communication line LAN-4
6. Control valve with TCMTM-172
OFF vehicle7. Front brake (brake band)
TM-1728. Input clutchTM-172
9. Gear systemTM-172
10. High and low reverse clutchTM-172
23Vehicle cannot be
started from D1.ON vehicle
1. Fluid level and state
TM-148
2. Accelerator pedal position sensor TM-71
3. Line pressure testTM-157
4. CAN communication line LAN-4
5. Control valve with TCMTM-172
OFF vehicle6. Torque converter
TM-172
7. Oil pump assemblyTM-223
8. 3rd one-way clutchTM-172
9. 1st one-way clutchTM-232
10. Gear systemTM-172
11. Reverse brakeTM-172
12. Forward one-way clutch (Parts behind drum support is im-
possible to perform inspection by disassembly. Refer to TM-
8, TM-9. TM-172
13. Forward brake (Parts behind drum support is impossible
to perform inspection by disassembly. Refer to
TM-8
, TM-9. TM-172
24
Does not lock-up. ON vehicle1. Fluid level and state
TM-148
2. Line pressure testTM-157
3. Engine speed signal TM-53
4. Input speed sensorTM-48
5. Torque converter clutch solenoid valveTM-65
6. CAN communication line LAN-4
7. Control valve with TCMTM-172
OFF vehicle8. Torque converter
TM-1729. Oil pump assemblyTM-172
No. ItemsSymptom Condition Diagnostic ItemReference
page
Revision: April 20092010 QX56