2008 INFINITI QX56 ECU

P0734 4GR INCORRECT RATIOTM-59
< COMPONENT DIAGNOSIS >
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P0734 4GR INCORRECT RATIO
DescriptionINFOID:0000000001604065
This malfunction is detected when the A/T does not shift into 4GR position as instructed by TCM. This is not
only caused by electrical malfunction (circuits open or shorted) but also by mechanical malfunction such as
control valve sticking, improper solenoid valve operation.
On Board Diagnosis LogicINFOID:0000000001604066
• This is an OBD-II self-diagnostic item.
• Diagnostic trouble code “P0734” is detected when TCM detec ts any inconsistency in the actual gear ratio.
Possible CauseINFOID:0000000001604067
• Harness or connectors
(Solenoid circuits are open or shorted.)
• Input clutch solenoid valve
• Front brake solenoid valve
• Direct clutch solenoid valve
• High and low reverse clutch solenoid valve
• Each clutch
• Hydraulic control circuit
DTC Confirmation ProcedureINFOID:0000000001604068
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 the engine and select “DATA MONITOR” mode for “TRANSMISSION” with CONSULT-III.
2. Make sure that “ATF TEMP 1” is within the following range. ATF TEMP 1: 20 °C – 140 °C
If out of range, drive vehicle to warm ATF or stop engine to cool ATF.
3. Select “4TH GR FNCTN P0734” of “DTC WORK SUPPORT” mode for “TRANSMISSION” with CON-
SULT-III.
4. Drive vehicle and maintain the following conditions.
VEHICLE SPEED: 10 km/h (6 MPH) or more
ACCELE POSI: 0.6/8 or more
ENGINE SPEED: INPUT SPEED − 50 rpm or more
INPUT SPEED: 300 rpm or more
GEAR: “4” position
MANU MODE SW: ON
5. Keep the current driving status for at least 5 consecutive seconds if CONSULT-III screen changes from “OUT OF CONDITION” to “TESTING”.
CAUTION:
If “TESTING” does not appear on CONSULT-III for a long time, select “SELF-DIAG RESULTS”. In
case a 1st trip DTC other than P0734 is shown, refer to “ TM-116, "
DTC No. Index"”.
If “COMPLETED RESULT NG” is detected, go toTM-60, "
Diagnosis Procedure".
If “STOP VEHICLE” is detec ted, go to the following step.
6. Stop vehicle.
7. Drive vehicle in “D” position allowing it to shift from 1GR to 5GR and check shift timing and shift shock.
- Touch “OK” to complete the inspection when normally shifted from the 1GR to 5GR.
- Touch “NG” when an unusual shift shock, etc. occurs in spite of shifting from the 1GR to 5GR. Go to TM-
189, "Description".
-Perform TM-32, "
CONSULT-III Functi on (TRANSMISSION)" when not shifted from the 1GR to 5GR. (Nei-
ther “OK” nor “NG” are indicated.)
Revision: March 2010 2008 QX56

P0735 5GR INCORRECT RATIOTM-61
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P0735 5GR INCORRECT RATIO
DescriptionINFOID:0000000001604070
This malfunction is detected when the A/T does not shift into 5GR position as instructed by TCM. This is not
only caused by electrical malfunction (circuits open or shorted) but also by mechanical malfunction such as
control valve sticking, improper solenoid valve operation.
On Board Diagnosis LogicINFOID:0000000001604071
• This is an OBD-II self-diagnostic item.
• Diagnostic trouble code “P0735” is detected when TCM detec ts any inconsistency in the actual gear ratio.
Possible CauseINFOID:0000000001604072
• Harness or connectors
(Solenoid circuits are open or shorted.)
• Input clutch solenoid valve
• Front brake solenoid valve
• Direct clutch solenoid valve
• High and low reverse clutch solenoid valve
• Each clutch
• Hydraulic control circuit
DTC Confirmation ProcedureINFOID:0000000001604073
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 the engine and select “DATA MONITOR” mode for “TRANSMISSION” with CONSULT-III.
2. Make sure that “ATF TEMP 1” is within the following range. ATF TEMP 1: 20 °C – 140 °C
If out of range, drive vehicle to warm ATF or stop engine to cool ATF.
3. Select “5TH GR FNCTN P0735” of “DTC WORK SUPPORT” mode for “TRANSMISSION” with CON-
SULT-III.
4. Drive vehicle and maintain the following conditions.
VEHICLE SPEED: 10 km/h (6 MPH) or more
ACCELE POSI: 0.6/8 or more
ENGINE SPEED: INPUT SPEED − 50 rpm or more
INPUT SPEED: 300 rpm or more
GEAR: “5” position
MANU MODE SW: ON
5. Keep the current driving status for at least 5 consecutive seconds if CONSULT-III screen changes from “OUT OF CONDITION” to “TESTING”.
CAUTION:
If “TESTING” does not appear on CONSULT-III for a long time, select “SELF-DIAG RESULTS”. In
case a 1st trip DTC other than P0735 is shown, refer to “ TM-116, "
DTC No. Index"”.
If “COMPLETED RESULT NG” is detected, go to TM-62, "
Diagnosis Procedure".
If “STOP VEHICLE” is detec ted, go to the following step.
6. Stop vehicle.
7. Drive vehicle in “D” position allowing it to shift from 1GR to 5GR and check shift timing and shift shock.
- Touch “OK” to complete the inspection when normally shifted from the 1GR to 5GR.
- Touch “NG” when an unusual shift shock, etc. occurs in spite of shifting from the 1GR to 5GR. Go to TM-
189, "Description".
-Perform TM-32, "
CONSULT-III Functi on (TRANSMISSION)" when not shifted from the 1GR to 5GR. (Nei-
ther “OK” nor “NG” are indicated.)
Revision: March 2010 2008 QX56

P0740 TORQUE CONVERTERTM-63
< COMPONENT DIAGNOSIS >
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P0740 TORQUE CONVERTER
DescriptionINFOID:0000000001604075
• The torque converter clutch solenoid valve is activated, with the gear in D4, D5 by the TCM in response to
signals sent from the input speed s ensor and accelerator pedal position s ensor (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 Val ue in Data Monitor ModeINFOID:0000000001604076
On Board Diagnosis LogicINFOID:0000000001604077
• 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:0000000001604078
• Torque converter clutch solenoid valve
• Harness or connectors
(The solenoid circuit is open or shorted.)
DTC Confirmation ProcedureINFOID:0000000001604079
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 SPEED SE: 80 km/h (50 MPH) or more
ACCELE POS: 0.5/8 - 1.0/8
SELECTOR LEVER: “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-63, "
Diagnosis Procedure".
WITH GST
Follow the procedure “With CONSULT-III”.
Diagnosis ProcedureINFOID:0000000001604080
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 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: March 2010 2008 QX56

P1705 TP SENSORTM-69
< COMPONENT DIAGNOSIS >
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P1705 TP SENSOR
DescriptionINFOID:0000000001604093
Electric throttle control actuator consists of throttle control motor, accelerator pedal position sensor, throttle
position sensor, etc. The actuator sends a signal to the ECM, and ECM sends signals to TCM with CAN com-
munication.
CONSULT-III Reference Val ue in Data Monitor ModeINFOID:0000000001604094
On Board Diagnosis LogicINFOID:0000000001604095
• This is not an OBD-II self-diagnostic item.
• Diagnostic trouble code “P1705” with CONSULT-III is detected when TCM does not receive the proper
accelerator pedal position signals (input by CAN communication) from ECM.
Possible CauseINFOID:0000000001604096
Harness or connectors
(The sensor circuit is open or shorted.)
DTC Confirmation ProcedureINFOID:0000000001604097
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 “TRANSMISSION” with CONSULT-III.
3. Start engine and let it idle for 1 second.
4. If DTC is detected, go to TM-69, "
Diagnosis Procedure".
Diagnosis ProcedureINFOID:0000000001604098
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 DTC WITH TCM
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. Depress accelerator pedal and read out the value of “ACCELE POSI”.
4. Select “SELF-DIAG RESULTS” mode for “T RANSMISSION” with CONSULT-III. Refer to TM-32, "
CON-
SULT-III Function (TRANSMISSION)".
Item name Condition Display value (Approx.)
ACCELE POSI Released accelerator pedal.
0.0/8
Fully depressed accelerator pedal. 8/8
Item nameCondition Display value
(Approx.)
ACCELE POSI Released accelerator pedal.
0.0/8
Fully depressed accelerator pedal. 8/8
Revision: March 2010 2008 QX56

P1710 TRANSMISSION FLUID TEMPERATURE SENSOR
TM-71
< COMPONENT DIAGNOSIS >
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P1710 TRANSMISSION FLUI D TEMPERATURE SENSOR
DescriptionINFOID:0000000001604099
The A/T fluid temperature sensor detects the A/ T fluid temperature and sends a signal to the TCM.
CONSULT-III Reference Value in Data Monitor ModeINFOID:0000000001604100
On Board Diagnosis LogicINFOID:0000000001604101
• This is an OBD-II self-diagnostic item.
• Diagnostic trouble code “P1710 (A/T), P0710 (ENGINE)” with CONSULT-III is detected when TCM receives
an excessively low or high voltage from the sensor.
Possible CauseINFOID:0000000001604102
• Harness or connectors (The sensor circuit is open or shorted.)
• A/T fluid temperature sensors 1, 2
DTC Confirmation ProcedureINFOID:0000000001604103
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 10 minutes (Total). (It is not necessary to maintain continuously.)
VHCL SPEED SE: 10 km/h (6 MPH) or more
THRTL POS SEN: More than 1.0/8
Selector lever: “D” position
4. If DTC is detected, go to TM-71, "
Diagnosis Procedure".
WITH GST
Follow the procedure “With CONSULT-III”.
Diagnosis ProcedureINFOID:0000000001604104
1.CHECK A/T FLUID TEMPERATURE SENSOR 1 SIGNAL
With CONSULT-III
1. Start engine.
2. Select “ECU INPUT SIGNALS” in “DATA MONITO R” mode for “TRANSMISSION” with CONSULT-III.
3. Read out the value of “ATF TEMP SE 1”.
OK or NG
OK >> GO TO 2.
NG >> GO TO 3.
Item name Condition °C ( °F) Display value (Approx.)
ATF TEMP SE 1 0 (32) - 20 (68) - 80 (176) 3.3 - 2.7 - 0.9 V
ATF TEMP SE 2 3.3 - 2.5 - 0.7 V
Item nameCondition °C ( °F) Display value (Approx.)
ATF TEMP SE 1 0 (32) - 20 (68) - 80 (176) 3.3 - 2.7 - 0.9 V
Revision: March 2010 2008 QX56

TM-72
< COMPONENT DIAGNOSIS >
P1710 TRANSMISSION FLUID TEMPERATURE SENSOR
2.CHECK A/T FLUID TEMPERATURE SENSOR 2 SIGNAL
With CONSULT-III
1. Start engine.
2. Select “ECU INPUT SIGNALS” in “DATA MONI TOR” mode for “TRANSMISSION” with CONSULT-III.
3. Read out the value of “ATF TEMP SE 2”.
OK or NG
OK >> GO TO 8.
NG >> GO TO 5.
3.CHECK A/T FLUID TEMPERATURE SENSOR 1
Check A/T fluid temperature sensor 1. Refer to TM-73, "
Component Inspection".
OK or NG
OK >> GO TO 4.
NG >> Replace the control valve with TCM. Refer to TM-201, "
Control Valve with TCM and A/T Fluid
Temperature Sensor 2".
4.CHECK SUB-HARNESS
1. Disconnect transmission range switch connector and TCM connector.
2. Check continuity between transmission range switch connector (A) terminals and TCM connector (B) terminals.
3. If OK, check harness for short to ground and short to power.
OK or NG
OK >> GO TO 7.
NG >> Replace open circuit or short to ground and short to power in harness or connectors.
5.CHECK A/T FLUID TEMPERATURE SENSOR 2
Check A/T fluid temperature sensor 2. Refer to TM-73, "
Component Inspection".
OK or NG
OK >> GO TO 6.
NG >> Replace the A/T fluid temperature sensor 2. Refer to TM-201, "
Control Valve with TCM and A/T
Fluid Temperature Sensor 2".
6.CHECK TERMINAL CORD ASSEMBLY
1. Disconnect A/T fluid temperature sensor 2 connector and TCM connector.
2. Check continuity between A/T fluid temperature sensor 2 con- nector terminals and TCM connector terminals.
Item name Condition °C (°F) Display value (Approx.)
ATF TEMP SE 2 0 (32) - 20 (68) - 80 (176) 3.3 - 2.5 - 0.7 V
Item Connector Terminal Continuity
Transmission range switch con-
nector F505 (A)
6
Ye s
TCM connector F503 (B)19
Transmission range switch con-
nector F505 (A)
7
Ye s
TCM connector F503 (B)18
JSDIA1330ZZ
Item Connector Terminal Continuity
A/T fluid temperature sensor 2
connector F507
1
Ye s
TCM connector F5023
A/T fluid temperature sensor 2
connector F507
2
Ye s
TCM connector F5025
SCIA5462E
Revision: March 2010 2008 QX56

TM-74
< COMPONENT DIAGNOSIS >
P1721 VEHICLE SPEED SIGNAL
P1721 VEHICLE SPEED SIGNAL
DescriptionINFOID:0000000001604106
The vehicle speed signal is transmitted from combination meter to TCM by CAN communication line. The sig-
nal functions as an auxiliary device to the output speed sensor when it is malfunctioning. The TCM will then
use the vehicle speed signal.
CONSULT-III Reference Value in Data Monitor ModeINFOID:0000000001604107
On Board Diagn osis LogicINFOID:0000000001604108
• This is not an OBD-II self-diagnostic item.
• Diagnostic trouble code “P1721” with CONSULT-III is det ected when TCM does not receive the proper vehi-
cle speed signal (input by CAN communication) from combination meter.
Possible CauseINFOID:0000000001604109
Harness or connectors
(The sensor circuit is open or shorted.)
DTC Confirmation ProcedureINFOID:0000000001604110
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 “TRANSMISSION” with CONSULT-III.
3. Start engine and maintain the following conditions for at least 5 consecutive seconds. ACCELE POS: 1/8 or less
VHCL SPEED SE: 30 km/h (17 MPH) or more
4. If DTC is detected, go to TM-74, "
Diagnosis Procedure".
Diagnosis ProcedureINFOID:0000000001604111
1.CHECK CAN COMMUNICATION LINE
Perform the self-diagnosis. Refer 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 INPUT SIGNAL
With CONSULT-III
1. Start engine.
2. Select “ECU INPUT SIGNALS” in “DATA MONI TOR” mode for “TRANSMISSION” with CONSULT-III.
3. Drive vehicle and read out the value of “VHCL/S SE·MTR”.
OK or NG
Item name Condition Display value (km/h)
VHCL/S SE·MTR During driving Approximately matches the speedometer reading.
Item nameCondition Displa y value (Approx.)(km/h)
VHCL/S SE·MTR During driving Approximately matches the speed-
ometer reading.
Revision: March 2010
2008 QX56

TM-76
< COMPONENT DIAGNOSIS >
P1730 INTERLOCK
P1730 INTERLOCK
DescriptionINFOID:0000000001604112
• Fail-safe function to detect interlock conditions.
On Board Diagnosis LogicINFOID:0000000001604113
• This is an OBD-II self-diagnostic item.
• Diagnostic trouble code “P1730” with CONSULT-III is detected when TCM does not receive the proper volt-
age signal from the sensor and switch.
• TCM monitors and compares gear position and conditions of each ATF pressure switch when gear is steady.
Possible CauseINFOID:0000000001604114
• Harness or connectors (The solenoid and switch circuit is open or shorted.)
• Low coast brake solenoid valve
• ATF pressure switch 2
DTC Confirmation ProcedureINFOID:0000000001604115
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 “TRANSMISSION” with CONSULT-III.
3. Start engine.
4. Drive vehicle and maintain the following conditions for at least 2 consecutive seconds. Selector lever: “D” position
5. If DTC is detected, go to TM-5, "
Work Flow".
WITH GST
Follow the procedure “With CONSULT-III”.
Judgement of InterlockINFOID:0000000001604116
• When Interlock is judged to be malfunctioning, the vehi cle should be fixed in 2GR, and should be set in a
condition in which it can travel.
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 interlock is detected at the 3GR or more, it is locked at the 2GR.
Diagnosis ProcedureINFOID:0000000001604117
1.SELF-DIAGNOSIS
With CONSULT-III
1. Drive vehicle.
2. Stop vehicle and turn ignition switch “OFF”.
3. Turn ignition switch “ON”.
4. Select “SELF-DIAG RESULTS” mode fo r “TRANSMISSION” with CONSULT-III.
OK or NG
OK >> GO TO 2.
NG >> Check low coast brake solenoid valve circuit and function. Refer to TM-88, "
Diagnosis Proce-
dure", TM-90, "Diagnosis Procedure".
2.CHECK DTC
Perform “DTC Confirmation Procedure”.
Revision: March 2010 2008 QX56