2008 INFINITI QX56 check engine

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
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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

P0744 TORQUE CONVERTERTM-65
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P0744 TORQUE CONVERTER
DescriptionINFOID:0000000001604081
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:0000000001604082
On Board Diagnosis LogicINFOID:0000000001604083
• 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:0000000001604084
• Harness or connectors
(The solenoid circuit is open or shorted.)
• Torque converter clutch solenoid valve
• Hydraulic control circuit
DTC Confirmation ProcedureINFOID:0000000001604085
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
Selector lever: “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 Gear Shifting Occurs".
- 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-66, "
Diagnosis Procedure".
Refer to shift schedule, TM-291, "
Vehicle Speed at Which Gear Shifting Occurs".
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: March 2010 2008 QX56

TM-66
< COMPONENT DIAGNOSIS >
P0744 TORQUE CONVERTER
Diagnosis Procedure
INFOID:0000000001604086
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-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-201, "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-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: March 2010 2008 QX56

P0745 PRESSURE CONTROL SOLENOID ATM-67
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P0745 PRESSURE CONTROL SOLENOID A
DescriptionINFOID:0000000001604087
The line pressure solenoid valve regulates the oil pum p discharge pressure to suit the driving condition in
response to a signal sent from the TCM.
The line pressure duty cycle value is not consistent when the closed throttle position signal is “ON”.
To confirm the line pressure duty cycle at low pressu re, the accelerator (throttle) should be open until
the closed throttle posi tion signal is “OFF”.
CONSULT-III Reference Val ue in Data Monitor ModeINFOID:0000000001604088
On Board Diagnosis LogicINFOID:0000000001604089
• This is an OBD-II self-diagnostic item.
• Diagnostic trouble code “P0745” 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:0000000001604090
• Harness or connectors
(The solenoid circuit is open or shorted.)
• Line pressure solenoid valve
DTC Confirmation ProcedureINFOID:0000000001604091
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” and select “DATA MONITOR” mode for “ENGINE” with CONSULT-III.
2. Engine start and wait at least 5 second.
3. If DTC is detected, go to TM-67, "
Diagnosis Procedure".
WITH GST
Follow the procedure “With CONSULT-III”.
Diagnosis ProcedureINFOID:0000000001604092
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 “LINE PRES SOL” while driving.
OK or NG
OK >> GO TO 4.
NG >> GO TO 2.
2.CHECK TCM POWER SUPPLY AND GROUND CIRCUIT
Item name Condition Display value (Approx.)
LINE PRES SOL During driving0.2 - 0.6 A
Item nameCondition Display value (Approx.)
LINE PRES SOL During driving 0.2 - 0.6 A
Revision: March 2010 2008 QX56

P1705 TP SENSORTM-69
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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

TM-70
< COMPONENT DIAGNOSIS >
P1705 TP SENSOR
OK or NG
OK >> GO TO 4.
NG >> GO TO 3.
3.CHECK DTC WITH ECM
With CONSULT-III
1. Turn ignition switch “ON”. (Do not start engine.)
2. Select “SELF-DIAG RESULTS” mode for “ENGINE” with CONSULT-III. Refer to TM-32, "
CONSULT-III
Function (TRANSMISSION)".
OK or NG
OK >> GO TO 4.
NG >> Check the DTC detected item. Refer to TM-116, "
DTC No. Index".
• If CAN communication line is detected, go to TM-38, "
Description".
4.CHECK DTC
Perform “DTC Confirmation Procedure”.
• Refer to TM-69, "
DTC Confirmation Procedure".
OK or NG
OK >> INSPECTION END
NG >> GO TO 5.
5.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 6.
NG >> Repair or replace damaged parts.
6.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-201, "Control Valve with TCM and A/T Fluid
Temperature Sensor 2".
NG >> Repair or replace damaged parts.
Revision: March 2010 2008 QX56

P1710 TRANSMISSION FLUID TEMPERATURE SENSOR
TM-71
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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