torque INFINITI QX56 2010 Factory Service Manual

DIAGNOSIS SYSTEM (TCM)TM-33
< FUNCTION DIAGNOSIS >
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4GR INCORRECT RA-
TIO • A/T cannot shift to 4GR.
P0734 P0734TM-62
5GR INCORRECT RA-
TIO• A/T cannot shift to 5GR.
P0735 P0735TM-64
TORQUE CONVERT-
ER• Normal voltage not applied to solenoid due to cut line,
short, or the like. P0740 P0740
TM-65
TORQUE CONVERT-
ER• A/T cannot perform lock-up even if electrical circuit is
good.
• TCM detects as irregular by comparing difference val-
ue with slip rotation. P0744 P0744*2
TM-68
PC SOLENOID A• Normal voltage not applied to solenoid due to cut line,
short, or the like.
• TCM detects as irregular by comparing target value
with monitor value. P0745 P0745
TM-69
TP SENSOR• TCM does not receive the proper accelerator pedal po-
sition signals (input by CAN communication) from
ECM. P1705 P1705
TM-71
FLUID TEMP SENSOR• During running, the ATF temperature sensor signal
voltage is excessively high or low. P1710 P0710
TM-73
VEHICLE SPEED SIG-
NAL• Signal (CAN communication) from vehicle speed sig-
nal not input due to cut line or the like.
• Unexpected signal input during running. P1721
—TM-76
INTERLOCK • Except during shift change, the gear position and ATF
pressure switch states are monitored and comparative
judgement made. P1730 P1730
TM-78
1GR E/BRAKING• Each ATF pressure switch and solenoid current is
monitored and if a pattern is detected having engine
braking 1GR other than in the "1" position, a malfunc-
tion is detected. P1731
—TM-80
INPUT CLUTCH SOLE-
NOID • Normal voltage not applied to solenoid due to function-
al malfunction, cut line, short, or the like.
• TCM detects as irregular by comparing target value
with monitor value. P1752 P1752
TM-82
FR BRAKE SOLENOID• Normal voltage not applied to solenoid due to function-
al malfunction, cut line, short, or the like.
• TCM detects as irregular by comparing target value
with monitor value. P1757 P1757
TM-84
DRCT CLUTCH SOLE-
NOID• Normal voltage not applied to solenoid due to cut line,
short, or the like.
• TCM detects as irregular by comparing target value
with monitor value. P1762 P1762
TM-86
HLR CLUTCH SOLE-
NOID• Normal voltage not applied to solenoid due to function-
al malfunction, cut line, short, or the like.
• TCM detects as irregular by comparing target value
with monitor value. P1767 P1767
TM-88
L C BRAKE SOLENOID• Normal voltage not applied to solenoid due to function-
al malfunction, cut line, short, or the like. P1772 P1772
TM-90
Items (CONSULT-III
screen terms) Malfunction is detected when... TCM self-di-
agnosis OBD (DTC)
Reference
“TRANSMIS-
SION” with
CONSULT-III MIL indicator
lamp*1, “EN-
GINE” with
CONSULT-III or
GST
Revision: April 20092010 QX56

TM-34
< FUNCTION DIAGNOSIS >
DIAGNOSIS SYSTEM (TCM)
*1: Refer to EC-55, "Malfunction Indicator Lamp (MIL)".
*2:These malfunctions cannot be displayed MIL if another malfunction is assigned to MIL.
DATA MONITOR MODE
Display Items List
X: Standard, —: Not applicable
L C BRAKE SOLENOID • TCM detects an improper voltage drop when it tries to
operate the solenoid valve.
• Condition of ATF pressure switch 2 is different from
monitor value, and relation between gear position and
actual gear ratio is irregular. P1774 P1774*2
TM-93
NO DTC IS DETECTED
FURTHER TESTING
MAY BE REQUIRED• No NG item has been detected.
XX —
Items (CONSULT-III
screen terms) Malfunction is detected when... TCM self-di-
agnosis OBD (DTC)
Reference
“TRANSMIS-
SION” with
CONSULT-III MIL indicator
lamp*1, “EN-
GINE” with
CONSULT-III or
GST
Monitored item (Unit) Monitor Item Selection
Remarks
ECU IN-
PUT SIG-
NALS MAIN SIG-
NALS SELEC-
TION
FROM
MENU
VHCL/S SE-A/T (km/h) XXX Output speed sensor
VHCL/S SE-MTR (km/h) X— X —
ACCELE POSI (0.0/8) X— X Accelerator pedal position signal
THROTTLE POSI (0.0/8) XXXDegree of opening for accelerator recognized by
the TCM.
For fail-safe operation, the specific value used
for control is displayed.
CLSD THL POS (ON-OFF display) X— X
Signal input with CAN communications.
W/O THL POS (ON-OFF display) X— X
BRAKESW (ON-OFF display) X— X Stop lamp switch
GEAR —XXGear position recognized by the TCM updated
after gear-shifting.
ENGINE SPEED (rpm) XXX —
INPUT SPEED (rpm) XXX —
OUTPUT REV (rpm) XXX —
GEAR RATIO —XX —
TC SLIP SPEED (rpm) —XXDifference between engine speed and torque
converter input shaft speed.
F SUN GR REV (rpm) —— X —
F CARR GR REV (rpm) —— X —
ATF TEMP SE 1 (V) X— X —
ATF TEMP 1 (° C) —XX —
ATF TEMP 2 (° C) —XX —
BATTERY VOLT (V) X— X —
ATF PRES SW 1 (ON-OFF display) XXX —
ATF PRES SW 2 (ON-OFF display) XXX (for LC/B solenoid)
Revision: April 20092010 QX56

DIAGNOSIS SYSTEM (TCM)TM-39
< FUNCTION DIAGNOSIS >
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Erase Self-diagnosis
• In order to make it easier to find the cause of
hard-to-duplicate malfunctions, malfunction information is
stored into the control unit as necessary during use by the user. This memory is not erased no matter how
many times the ignition switch is turned ON and OFF.
• However, this information is erased by turning ignition switch OFF after executing self-diagnostics or by erasing the memory using the CONSULT-III.
No. Malfunctioning item No.Malfunctioning item
1 Output speed sensor TM-50
12 Interlock TM-78
2 Direct clutch solenoid TM-8613 1st engine braking TM-80
3 Torque converter TM-65, TM-6714 Starter relay TM-41
4 Line pressure solenoid TM-6915 Accelerator pedal position sensor TM-71
5 Input clutch solenoid TM-8216 Engine speed TM-53
6 Front brake solenoid TM-8417 CAN communication line TM-40
7 Low coast brake solenoid TM-90, TM-9218 1GR incorrect ratio TM-55
8 High and low reverse clutch solenoid TM-8819 2GR incorrect ratio TM-57
9 Transmission range switch TM-4520 3GR incorrect ratio TM-59
10 A/T fluid temperature sensor TM-7321 4GR incorrect ratio TM-61
11 Input speed sensor TM-4822 5GR incorrect ratio TM-63
Revision: April 20092010 QX56

P0740 TORQUE CONVERTERTM-65
< COMPONENT DIAGNOSIS >
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P0740 TORQUE CONVERTER
DescriptionINFOID:0000000005148593
• The torque converter clutch solenoid valve is activated, with the gear in D4, D5 by the TCM in response to
signals sent from the output speed sensor and accele rator pedal position sensor. Torque converter clutch
piston operation will then be controlled.
• Lock-up operation, however, is prohibited when A/T fluid temperature is too low.
• When the accelerator pedal is depressed (less than 1/8) in lock-up condition, the engine speed should not change abruptly. If there is a big jump in engine speed, there is no lock-up.
CONSULT-III Reference Val ue in Data Monitor ModeINFOID:0000000005148594
On Board Diagnosis LogicINFOID:0000000005148595
• This is an OBD-II self-diagnostic item.
• Diagnostic trouble code “P0740 TORQUE CONVERTER” wi th CONSULT-III is detected under the following
conditions.
- When TCM detects an improper voltage drop when it tries to operate the solenoid valve.
- When TCM detects as irregular by comparing target value with monitor value.
Possible CauseINFOID:0000000005148596
• Torque converter clutch solenoid valve
• Harness or connectors (The solenoid circuit is open or shorted.)
DTC Confirmation ProcedureINFOID:0000000005148597
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. Turn ignition switch “ON”. (Do not start engine.)
2. Select “DATA MONITOR” mode for “ENGINE” with CONSULT-III.
3. Start engine and maintain the following conditions for at least 5 consecutive seconds.
VHCL/S SE-A/T: 80 km/h (50 MPH) or more
ACCELE POSI: 0.5/8 - 1.0/8
SLCT LVR POSI: “D” position
Driving location: Driving the vehic le uphill (increased engine load) will help maintain the driving
conditions required for this test.
4. If DTC is detected go to TM-65, "
Diagnosis Procedure".
WITH GST
Follow the procedure “With CONSULT-III”.
Diagnosis ProcedureINFOID:0000000005148598
1.CHECK INPUT SIGNAL
With CONSULT-III
1. Turn ignition switch “ON”.
2. Select “MAIN SIGNALS” in “DATA MONITOR” mode for “TRANSMISSION” 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-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 >
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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 >
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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