2008 INFINITI QX56 transmission

MAIN POWER SUPPLY AND GROUND CIRCUITTM-93
< COMPONENT DIAGNOSIS >
CEF
G H
I
J
K L
M A
B
TM
N
O P
5.DETECT MALFUNCTIONING ITEM
Check the following items:
• The A/T assembly harness connector terminals for damage or loose connection with harness connector.
OK or NG
OK >> GO TO 6.
NG >> Repair or replace damaged parts.
6.PERFORM SELF-DIAGNOSIS
Perform self-diagnosis. Refer to TM-32, "
CONSULT-III Function (TRANSMISSION)".
OK or NG
OK >> INSPECTION END
NG-1 >> Self-diagnosis does not activate: GO TO 7.
NG-2 >> DTC is displayed: Check t he malfunctioning system. Refer to TM-32, "
CONSULT-III Function
(TRANSMISSION)".
7.CHECK TERMINAL CORD ASSEMBLY
1. Remove control valve with TCM. Refer to TM-201, "
Control Valve with TCM and A/T Fluid Temperature
Sensor 2".
2. Disconnect A/T assembly harness connector and TCM connector.
3. Check continuity between A/T assembly harness connector ter- minals and TCM connector terminals.
4. Check continuity between A/T assembly harness connector ter- minals and TCM connector terminals.
5. If OK, check harness for short to ground and short to power.
OK or NG
OK >> Replace the control valve with TCM. Refer to TM-201, "Control Valve with TCM and A/T Fluid
Temperature Sensor 2".
NG >> Replace open circuit or short to ground and short to power in harness or connectors.
Item Connector Terminal Continuity
A/T assembly harness con-
nector F9
1
Ye s
TCM connector F5029
A/T assembly harness con-
nector F9
2
Ye s
TCM connector F50210
A/T assembly harness con-
nector F9
6
Ye s
TCM connector F5024
SCIA5464E
Item Connector Terminal Continuity
A/T assembly harness con-
nector F9
5
Ye s
TCM connector F50421
A/T assembly harness con-
nector F9
10
Ye s
TCM connector F50422
SCIA5465E
Revision: March 2010 2008 QX56

TM-94
< COMPONENT DIAGNOSIS >
CLOSED THROTTLE POSITION AND WIDE OPEN THROTTLE POSITION CIR-
CUIT
CLOSED THROTTLE POSITION AND WIDE OPEN THROTTLE POSITION
CIRCUIT
CONSULT-III Reference Value in Data Monitor ModeINFOID:0000000001604161
Diagnosis ProcedureINFOID:0000000001604162
1.CHECK CAN COMMUNICATION LINE
Perform the self-diagnosis. Refer to TM-32, "
CONSULT-III Function (TRANSMISSION)".
Is a malfunction in the CAN communication indicated in the results?
YES >> Check CAN communication line. Refer to TM-38.
NO >> GO TO 2.
2.CHECK THROTTLE POSI TION SIGNAL CIRCUIT
With CONSULT-III
1. Turn ignition switch “ON”. (Do not start engine.)
2. Select “ECU INPUT SIGNALS” in “DATA MONI TOR” mode for “TRANSMISSION” with CONSULT-III.
3. Depress accelerator pedal and read out the value of “CLSD THL POS” and “W/O THL POS”.
OK or NG
OK >> INSPECTION END
NG >> Check the following items. If NG, repair or replace damaged parts. • Perform the self-diagnosis for “ENGINE” with CONSULT-III.
• Open circuit or short to ground or shor t to power in harness or connectors.
• Pin terminals for damage or loos e connection with harness connector.
Item nameCondition Display value
CLSD THL POS Released accelerator pedal.
ON
Fully depressed accelerator pedal. OFF
W/O THL POS Fully depressed accelerator pedal.
ON
Released accelerator pedal. OFF
Accelerator Pedal OperationMonitor Item
CLSD THL POS W/O THL POS
Released ONOFF
Fully depressed OFFON
Revision: March 2010 2008 QX56

BRAKE SIGNAL CIRCUITTM-95
< COMPONENT DIAGNOSIS >
CEF
G H
I
J
K L
M A
B
TM
N
O P
BRAKE SIGNAL CIRCUIT
CONSULT-III Reference Val ue in Data Monitor ModeINFOID:0000000001604163
Diagnosis ProcedureINFOID:0000000001604164
1.CHECK CAN COMMUNICATION LINE
Perform the self-diagnosis. Refer to TM-32, "
CONSULT-III Function (TRANSMISSION)".
Is a malfunction in the CAN communication indicated in the results?
YES >> Check CAN communication line. Refer to TM-38, "Diagnosis Procedure".
NO >> GO TO 2.
2.CHECK STOP LAMP SWITCH CIRCUIT
With CONSULT-III
1. Turn ignition switch “ON”. (Do not start engine.)
2. Select “ECU INPUT SIGNALS” in “DATA MONITO R” mode for “TRANSMISSION” with CONSULT-III.
3. Read out ON/OFF switching action of the “BRAKE SW”.
OK or NG
OK >> INSPECTION END
NG >> GO TO 3.
3.CHECK STOP LAMP SWITCH
Check continuity between stop lamp switch terminals 1 and 2.
Check stop lamp switch after adjusting brake pedal — refer to
BR-15, "
Inspection and Adjustment".
OK or NG
OK >> Check stop lamp switch circuit.
NG >> Repair or replace stop lamp switch.
Item name Condition Display value
BRAKE SW Depressed brake pedal.
ON
Released brake pedal. OFF
ConditionContinuity
When brake pedal is depressed Yes
When brake pedal is released No
AWDIA0165ZZ
Revision: March 2010 2008 QX56

TM-96
< COMPONENT DIAGNOSIS >
TOW MODE SWITCH
TOW MODE SWITCH
DescriptionINFOID:0000000001604165
When tow mode switch is “ON”, tow mode switch signals are sent to TCM from combination meter by CAN
communication line.Then it`s a tow mode condition.
Diagnosis ProcedureINFOID:0000000001604167
1.CHECK CAN COMMUNICATION LINE
Perform the self-diagnosis. Refer to TM-32, "
CONSULT-III Function (TRANSMISSION)".
Is any malfunction in the CAN communication indicated in the results?
YES >> Check CAN communication line. Refer to TM-38.
NO >> GO TO 2.
2.CHECK POWER SOURCE
1. Turn ignition switch “ON”. (Do not start engine.)
2. Check the voltage between tow mode switch connector M258 terminal 1 and ground.
OK or NG
OK >> INSPECTION END
NG >> GO TO 3.
3.CHECK TOW MODE SWITCH
1. Turn ignition switch “OFF”.
2. Disconnect tow mode switch connector.
3. Check continuity between tow mode switch terminals 1 and 2.
OK or NG
OK >> GO TO 4.
NG >> Repair or replace tow mode switch.
4.DETECT MALFUNCTIONING ITEM
Check the following items. If any items are damaged, repair or replace damaged parts.
• Harness for short or open between combination meter connector terminal 35 and tow mode switch connec- tor terminal 1.
• Harness for short or open between tow mode switch connector terminal 2 and ground.
OK or NG
OK >> GO TO 5.
NG >> Repair or replace damaged parts.
5.CHECK COMBINATION METER
Check the combination meter. Refer to MWI-4, "
Work Flow".
OK or NG
OK >> INSPECTION END
NO >> Repair or replace damaged parts.
Condition To w m o d e
switch Data (Approx.)
When ignition switch is turned to “ON” ON
0V
OFF Battery voltage
SCIA5156E
Condition Continuity
Tow mode switch “ON” Yes
Tow mode switch “OFF” No
SCIA5584E
Revision: March 2010 2008 QX56

TM-114
< ECU DIAGNOSIS >
TCM
Fail-Safe
INFOID:0000000001604175
The TCM has an electrical fail-safe mode. This mode make s it possible to operate even if there is an error in a
main electronic control input/output signal circuit.
The TCM has an electrical fail-safe mode. This mode make s it possible to operate even if there is an error in a
main electronic control input/output signal circuit. In fa il-safe mode the transmission is fixed in 2nd, 4th or 5th
(depending on the breakdown position), so the customer should feel “slipping” or “poor acceleration”.
AADIA0076GB
Revision: March 2010 2008 QX56

TCM
TM-115
< ECU DIAGNOSIS >
C EF
G H
I
J
K L
M A
B
TM
N
O P
Even when the electronic circuits are normal, under s pecial 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 vehicle 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 t here is a malfunction in one of the systems. And if output
speed sensor has unusual cases, 5GR is prohibited.
Accelerator Pedal 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 tr ansmission is fixed in 2GR to make driving possible.
NOTE:
When the vehicle is driven fixed in 2GR, a inpu t 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 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 4th gear 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: March 2010 2008 QX56

TM-116
< ECU DIAGNOSIS >
TCM
High and Low Reverse 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 turbine revolution sensors, 5GR is prohibited.
DTC Inspection Priority ChartINFOID:0000000001604176
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 perform the trouble diagnosis for DTC U1000. Refer to
TM-38, "
Diagnosis Procedure".
DTC No. IndexINFOID:0000000001604177
NOTE:
If DTC U1000 is displayed with other DTC, first pe rform the trouble diagnosis for DTC U1000. Refer to
TM-38, "
Diagnosis Procedure".
Priority Detected items (DTC)
1 U1000 CAN COMM CIRCUIT
2 Except above
DTC
Items
(CONSULT- III screen terms) Reference page
OBD- II
Except OBD- II
CONSULT- III GST (*1) CONSULT- III only
“TRANSMISSION”
— P0615STARTER RELAY TM-39
P0700P0700TRANSMISSION CONT TM-42
P0705P0705T/M RANGE SWITCH A TM-43
P0710P1710TRANS FLUID TEMP SEN TM-71
P0717P0717INPUT SPEED SENSOR A TM-46
P0720P0720OUTPUT SPEED SENSOR TM-49
—P0725ENGINE SPEED TM-51
P0731P07311GR INCORRECT RATIO TM-54
P0732P07322GR INCORRECT RATIO TM-56
P0733P07333GR INCORRECT RATIO TM-58
P0734P07344GR INCORRECT RATIO TM-60
P0735P07355GR INCORRECT RATO TM-62
P0740P0740TORQUE CONVERTER TM-63
P0744 P0744 TORQUE CONVERTER TM-66
P0745P0745PC SOLENOID A TM-67
—P1705TP SENSOR TM-69
—P1721VEHICLE SPEED SIGNAL TM-74
P1730P1730INTERLOCK TM-76
—P17311GR E/BRAKING TM-78
P1752P1752INPUT CLUTCH SOL TM-80
P1757P1757FR BRAKE SOLENOID TM-82
P1762P1762DRCT CLUTCH SOL TM-84
P1767P1767HLR CLUTCH SOLENOID TM-86
Revision: March 2010 2008 QX56

TCM
TM-117
< ECU DIAGNOSIS >
C EF
G H
I
J
K L
M A
B
TM
N
O P
*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:0000000001604178
NOTE:
If DTC U1000 is displayed with other DTC, first pe rform the trouble diagnosis for DTC U1000. Refer to
TM-38, "
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-88
P1774 (2*) P1774 LC BRAKE SOLENOID TM-90
U1000U1000CAN COMM CIRCUIT TM-38
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”
1GR E/BRAKING —P1731TM-78
1GR INCORRECT RATIO P0731P0731TM-54
2GR INCORRECT RATIO P0732P0732TM-56
3GR INCORRECT RATIO P0733P0733TM-58
4GR INCORRECT RATIO P0734P0734TM-60
5GR INCORRECT RATIO P0735P0735TM-62
INTERLOCK P1730P1730TM-76
TORQUE CONVERTER P0744 P0744 TM-66
TRANS FLUID TEMP SEN P0710P1710TM-71
CAN COMM CIRCUIT U1000U1000TM-38
DRCT CLUTCH SOL P1762P1762 TM-84
ENGINE SPEED —P0725TM-51
FR BRAKE SOLENOID P1757P1757TM-82
HLR CLUTCH SOLENOID P1767P1767TM-86
INPUT CLUTCH SOL P1752P1752TM-80
PC SOLENOID A P0745P0745TM-67
L C BRAKE SOLENOID P1772P1772TM-88
L C BRAKE SOLENOID P1774 P1774 TM-90
T/M RANGE SWITCH A P0705P0705TM-43
STARTER RELAY —P0615TM-39
TORQUE CONVERTER P0740P0740TM-63
TRANSMISSION CONT P0700P0700TM-42
TP SENSOR —P1705TM-69
INPUT SPEED SENSOR A P0717P0717TM-46
VEHICLE SPEED SIGNAL —P1721TM-74
OUTPUT SPEED SENSOR P0720P0720TM-49
Revision: March 2010 2008 QX56