2009 INFINITI QX56 torque

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-90
NO DTC IS DETECTED
FURTHER TESTING
MAY BE REQUIRED No NG item has been detected. X X
Items (CONSULT-III
screen terms) Malfunction is detected when... TCM self-di-
agnosis OBD (DTC)
Reference page
“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) X X X 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) X X X Degree 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
BRAKE SW (ON-OFF display) X — X Stop lamp switch
GEAR — X X Gear position recognized by the TCM updated
after gear-shifting
ENGINE SPEED (rpm) X X X
INPUT SPEED (rpm) X X X
OUTPUT REV (rpm) X X X
GEAR RATIO — X X
TC SLIP SPEED (rpm) — X X Difference 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 SE 2 (V) X — X
ATF TEMP 1 ( °C) — X X
ATF TEMP 2 ( °C) — X X
BATTERY VOLT (V) X — X
ATF PRES SW 2 (ON-OFF display) X X X (for LC/B solenoid)
Revision: December 20092009 QX56

TM-64
< COMPONENT DIAGNOSIS >
P0740 TORQUE CONVERTER
P0740 TORQUE CONVERTER
DescriptionINFOID:0000000003771890
 The torque converter clutch solenoid valve is activated, with the gear in D4, D5 by the TCM in response to
signals sent from the vehicle speed sensor and accelera tor pedal position sensor (throttle 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 Value in Data Monitor ModeINFOID:0000000003771891
On Board Diagnosis LogicINFOID:0000000003771892
 This is an OBD-II self-diagnostic item.
 Diagnostic trouble code “P0740” with 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:0000000003771893
 Torque converter clutch solenoid valve
 Harness or connectors (The solenoid circuit is open or shorted.)
DTC Confirmation ProcedureINFOID:0000000003771894
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 proc edure 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 vehicle uphill (increased engine load) will help maintain the driving
conditions required for this test.
4. If DTC is detected go to TM-64, "Diagnosis Procedure"
.
WITH GST
Follow the procedure “With CONSULT-III”.
Diagnosis ProcedureINFOID:0000000003771895
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 engine.
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: December 20092009 QX56

P0740 TORQUE CONVERTERTM-65
< COMPONENT DIAGNOSIS >
CEF
G H
I
J
K L
M A
B
TM
N
O P
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-92, "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-203, "Control Valve with TCM and A/T Fluid
Temperature Sensor 2".
NG >> Repair or replace damaged parts.
4.CHECK DTC
Perform “DTC Confirmation Procedure”.
 Refer to TM-64, "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: December 20092009 QX56

TM-66
< COMPONENT DIAGNOSIS >
P0744 TORQUE CONVERTER
P0744 TORQUE CONVERTER
DescriptionINFOID:0000000003771896
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 Value in Data Monitor ModeINFOID:0000000003771897
On Board Diagn osis LogicINFOID:0000000003771898
 This is an OBD-II self-diagnostic item.
 Diagnostic trouble code “P0744” with 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:0000000003771899
 Harness or connectors
(The solenoid circuit is open or shorted.)
 Torque converter clutch solenoid valve
 Hydraulic control circuit
DTC Confirmation ProcedureINFOID:0000000003771900
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 proc edure 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-291, "Vehicle Speed at Which Lock-up Occurs/Releases"
.
- If “TESTING” does not ap pear on CONSULT-III for a long ti me, 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 displayed. (If “NG” is displayed, refer to “DIAGNOSTIC PROCEDURE”.)
Refer to TM-67, "Diagnosis Procedure"
.
Refer to shift schedule, TM-291, "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: December 20092009 QX56

P0744 TORQUE CONVERTERTM-67
< COMPONENT DIAGNOSIS >
CEF
G H
I
J
K L
M A
B
TM
N
O P
Diagnosis ProcedureINFOID:0000000003771901
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.
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-92, "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-203, "Control Valve with TCM and A/T Fluid
Temperature Sensor 2".
NG >> Repair or replace damaged parts.
4.CHECK DTC
Perform “DTC Confirmation Procedure”.
 Refer to TM-66, "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: December 20092009 QX56

TM-116
< 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 t he 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 s peed sensor installed on the transmission and from com-
bination meter so normal driving is possible even if ther e 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” range 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 gear engine brake judgment malfunc tion, 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 se t 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 is not 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: December 20092009 QX56

TCM
TM-117
< 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 4th gear 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:0000000003771988
If some DTCs are displayed at the same time, per form 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-39, "Diagnosis Procedure"
.
DTC No. IndexINFOID:0000000003771989
NOTE:
If DTC U1000 is displayed with other DTC, first pe rform the trouble diagnosis for DTC U1000. Refer to
TM-39, "Diagnosis Procedure"
.
Priority Detected items (DTC)
1 U1000 CAN COMM CIRCUT
2 Except above
DTC Items
(CONSULT- III screen terms) Reference page
OBD- II Except OBD- II
CONSULT- III GST (*1) CONSULT- III only
“TRANSMISSION”
— P0615 STARTER RELAY TM-40
P0700 P0700 TRANSMISSION CONT TM-43
P0705 P0705 T/M RANGE SWITCH ATM-44
P0710 P1710 TRANS FLUID TEMP SENTM-72
P0717 P0717 INPUT SPEED SENSOR ATM-47
P0720 P0720 OUTPUT SPEED SENSORTM-50
— P0725 ENGINE SPEEDTM-52
P0731 P0731 1GR INCORRECT RATIO TM-55
P0732 P0732 2GR INCORRECT RATIOTM-57
P0733 P0733 3GR INCORRECT RATIOTM-59
P0734 P0734 4GR INCORRECT RATIOTM-61
P0735 P0735 5GR INCORRECT RATIOTM-63
P0740 P0740 TORQUE CONVERTERTM-64
P0744 P0744 TORQUE CONVERTERTM-67
P0745 P0745 PC SOLENOID ATM-68
— P1705 TP SENSORTM-70
— P1721 VEHICLE SPEED SIGNALTM-74
P1730 P1730 INTERLOCK TM-76
— P1731 1GR E/BRAKINGTM-78
P1752 P1752 INPUT CLUTCH SOLENOID TM-80
P1757 P1757 FR BRAKE SOLENOIDTM-82
P1762 P1762 DRCT CLUTCH SOLENOIDTM-84
P1767 P1767 HLR CLUTCH SOLLENOIDTM-86
Revision: December 20092009 QX56

TM-118
< 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:0000000003771990
NOTE:
If DTC U1000 is displayed with other DTC, first perform the trouble diagnosis for DTC U1000. Refer to
TM-39, "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 P1772 L C BRAKE SOLENOID
TM-88
P1774 (2*) P1774 L C BRAKE SOLENOID TM-90
U1000 U1000 CAN COMM CIRCUITTM-39
DTC
Items
(CONSULT- III screen terms) Reference page
OBD- II Except OBD- II
CONSULT- III GST (*1) CONSULT- III only
“TRANSMISSION”
Items
(CONSULT- III screen terms) DTC
Reference page
OBD- II Except OBD- II
CONSULT- III GST (*1) CONSULT- III only
“TRANSMISSION”
1ST E/BRAKING — P1731 TM-78
1GR INCORRECT RATIO P0731 P0731TM-55
2GR INCORRECT RATIO P0732 P0732TM-57
3GR INCORRECT RATIO P0733 P0733TM-59
4GR INCORRECT RATIO P0734 P0734TM-61
5GR INCORRECT RATIO P0735 P0735TM-63
INTERLOCK P1730 P1730TM-76
TORQUE CONVERTER P0744 P0744 TM-67
TRAXIS FLUID TEMP SEN P0710 P1710TM-72
CAN COMM CIRCUIT U1000 U1000TM-39
DRCT CLUTCH SOLENOID P1762 P1762 TM-84
ENGINE SPEED — P0725 TM-52
FR BRAKE SOLENOID P1757 P1757TM-82
HLR CLUTCH SOLENOID P1767 P1767TM-86
INPUT CLUTCH SOLENOID P1752 P1752TM-80
PC SOLENOID A P0745 P0745TM-68
LC BRAKE SOLENOID P1772 P1772TM-88
LC BRAKE SOLENOID P1774 P1774 TM-90
T/M RANGE SWITCH A P0705 P0705TM-44
STARTER RELAY — P0615TM-40
TORQUE CONVERTER P0740 P0740TM-64
TRANSMISSION CONT P0700 P0700TM-43
TP SENSOR — P1705TM-70
INPUT SPEED SENSOR A P0717 P0717TM-47
VEHICLE SPEED SIGNAL — P1721TM-74
OUTPUT SPEED SENSOR P0720 P0720TM-50
Revision: December 20092009 QX56