2007 INFINITI QX56 ECU

DTC P0720 VEHICLE SPEED SENSOR A/T (REVOLUTION SENSOR)
AT-107
< SERVICE INFORMATION >
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Diagnosis ProcedureINFOID:0000000003532297
1.CHECK INPUT SIGNAL
With CONSULT-II
1. Turn ignition switch “ON”.
2. Select “ECU INPUT SIGNALS” in “DATA MONITOR” mode for
“A/T” with CONSULT-II.
3. Start the engine.
4. Read out the value of “VHCL/S SE·A/T” while driving.
Check the value changes according to driving speed.
OK or NG
OK >> GO TO 6.
NG >> GO TO 2.
2.CHECK TCM POWER SUPPLY AND GROUND CIRCUIT
Check TCM power supply and ground circuit. Refer to AT-158
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 >> GO TO 4.
NG >> Repair or replace damaged parts.
4.CHECK SUB-HARNESS
1. Remove control valve with TCM. Refer to AT-210, "
Control Valve with TCM and A/T Fluid Temperature
Sensor 2".
2. Disconnect park/neutral position switch connector and TCM connector.
3. Check continuity between park/neutral position switch connector
terminals and TCM connector terminals.
4. If OK, check harness for short to ground and short to power.
5. Reinstall any part removed.
OK or NG
OK >> GO TO 5.
NG >> Replace open circuit or short to ground and short to power in harness or connectors.
5.REPLACE THE REVOLUTION SENSOR AND CHECK DTC
Item name Condition Display value (km/h)
VHCL/S SE·A/T During driving Approximately matches the
speedometer reading.
SCIA2148E
Item Connector Terminal Continuity
Park/neutral position switch
connectorF505 8
Ye s
TCM connector F503 20
Park/neutral position switch
connectorF505 9
Ye s
TCM connector F503 17
Park/neutral position switch
connectorF505 10
Ye s
TCM connector F503 16
SCIA5458E

DTC P0725 ENGINE SPEED SIGNAL
AT-109
< SERVICE INFORMATION >
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DTC P0725 ENGINE SPEED SIGNAL
DescriptionINFOID:0000000003532298
The engine speed signal is sent from the ECM to the TCM.
CONSULT-II Reference Value in Data Monitor ModeINFOID:0000000003532299
On Board Diagnosis LogicINFOID:0000000003532300
• This is not an OBD-II self-diagnostic item.
• Diagnostic trouble code “P0725 ENGINE SPEED SIG” with CONSULT-II is detected when TCM does not
receive the ignition signal from ECM during engine cranking or running.
Possible CauseINFOID:0000000003532301
Harness or connectors
(The ECM to the TCM circuit is open or shorted.)
DTC Confirmation ProcedureINFOID:0000000003532302
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-II
1. Turn ignition switch “ON” and select “DATA MONITOR” mode for
“A/T” with CONSULT-II.
2. Start engine and maintain the following conditions for at least 10
consecutive seconds.
VHCL SPEED SE: 10 km/h (6 MPH) or more
ACCELE POSI: More than 1/8
Selector lever: “D” position
3. If DTC is detected, go to AT-109, "
Diagnosis Procedure".
Diagnosis ProcedureINFOID:0000000003532303
1.CHECK CAN COMMUNICATION LINE
Perform the self-diagnosis. Refer to AT-83, "
CONSULT-II Function (A/T)".
Is a malfunction in the CAN communication indicated in the results?
YES >> Check CAN communication line. Refer to AT- 9 1.
NO >> GO TO 2.
2.CHECK DTC WITH TCM
With CONSULT-II
Item name Condition Display value (rpm)
ENGINE SPEED Engine running Closely matches the tachometer reading.
BCIA0031E

AT-110
< SERVICE INFORMATION >
DTC P0725 ENGINE SPEED SIGNAL
1. Start engine.
2. Select “ECU INPUT SIGNALS” in “DATA MONITOR” mode for
“A/T” with CONSULT-II.
3. While monitoring engine speed, check for engine speed change
corresponding to wide-open throttle position signal.
OK or NG
OK >> GO TO 3.
NG >> Check the ignition signal circuit.
• Refer to EC-626
.
3.CHECK DTC
Perform "DTC Confirmation Procedure".
• Refer to AT-109, "
DTC Confirmation Procedure".
OK or NG
OK >>INSPECTION END
NG >> GO TO 4.
4.CHECK TCM POWER SUPPLY AND GROUND CIRCUIT
Check TCM power supply and ground circuit. Refer to AT-158
.
OK or NG
OK >> GO TO 5.
NG >> Repair or replace damaged parts.
5.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 AT-210, "Control Valve with TCM and A/T Fluid Tem-
perature Sensor 2".
NG >> Repair or replace damaged parts.
Item name Condition Display value (rpm)
ENGINE SPEED Engine running Closely matches the tachometer reading.
PCIA0041E

DTC P0740 TORQUE CONVERTER CLUTCH SOLENOID VALVE
AT-111
< SERVICE INFORMATION >
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DTC P0740 TORQUE CONVERTER CLUTCH SOLENOID VALVE
DescriptionINFOID:0000000003532304
• 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 accelerator 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-II Reference Value in Data Monitor ModeINFOID:0000000003532305
On Board Diagnosis LogicINFOID:0000000003532306
• This is an OBD-II self-diagnostic item.
• Diagnostic trouble code “P0740 TCC SOLENOID/CIRC” with CONSULT-II 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:0000000003532307
• Torque converter clutch solenoid valve
• Harness or connectors
(The solenoid circuit is open or shorted.)
DTC Confirmation ProcedureINFOID:0000000003532308
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-II
1. Turn ignition switch “ON”. (Do not start engine.)
2. Select “DATA MONITOR” mode for “ENGINE” with CONSULT-II.
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 vehicle uphill (increased
engine load) will help maintain the driving conditions
required for this test.
4. If DTC is detected go to AT- 111 , "
Diagnosis Procedure".
WITH GST
Follow the procedure “With CONSULT-II”.
Diagnosis ProcedureINFOID:0000000003532309
1.CHECK INPUT SIGNAL
With CONSULT-II
Item name Condition Display value (Approx.)
TCC SOLENOIDWhen performing slip lock-up 0.2 - 0.4 A
When performing lock-up 0.4 - 0.6 A
BCIA0031E

AT-118
< SERVICE INFORMATION >
DTC P1705 THROTTLE POSITION SENSOR
1. Turn ignition switch “ON”. (Do not start engine.)
2. Select “ECU INPUT SIGNALS” in “DATA MONITOR” mode for
“A/T” with CONSULT-II.
3. Depress accelerator pedal and read out the value of “ACCELE
POSI”.
4. Select “SELF-DIAG RESULTS” mode for “A/T” with CONSULT-
II. Refer to AT-83, "
CONSULT-II Function (A/T)".
OK or NG
OK >> GO TO 4.
NG >> GO TO 3.
3.CHECK DTC WITH ECM
With CONSULT-II
1. Turn ignition switch “ON”. (Do not start engine.)
2. Select “SELF-DIAG RESULTS” mode for “ENGINE” with CON-
SULT-II. Refer to AT-83, "
CONSULT-II Function (A/T)".
OK or NG
OK >> GO TO 4.
NG >> Check the DTC detected item. Refer to AT-83, "
CON-
SULT-II Function (A/T)".
• If CAN communication line is detected, go to AT- 9 1
.
4.CHECK DTC
Perform “DTC Confirmation Procedure”.
• Refer to AT-117, "
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 AT-158
.
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 AT-210, "Control Valve with TCM and A/T Fluid Tem-
perature Sensor 2".
NG >> Repair or replace damaged parts.
Item name Condition Display value
(Approx.)
ACCELE POSIReleased accelerator pedal. 0.0/8
Fully depressed accelerator pedal. 8/8
PCIA0070E
BCIA0031E

DTC P1710 A/T FLUID TEMPERATURE SENSOR CIRCUIT
AT-121
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1. Start engine.
2. Select “ECU INPUT SIGNALS” in “DATA MONITOR” mode for
“A/T” with CONSULT-II.
3. Read out the value of “ATF TEMP SE 1”.
OK or NG
OK >> GO TO 2.
NG >> GO TO 3.
2.CHECK A/T FLUID TEMPERATURE SENSOR 2 SIGNAL
With CONSULT-II
1. Start engine.
2. Select “ECU INPUT SIGNALS” in “DATA MONITOR” mode for
“A/T” with CONSULT-II.
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 AT-122, "
Component Inspection".
OK or NG
OK >> GO TO 4.
NG >> Replace the control valve with TCM. Refer to AT-210, "
Control Valve with TCM and A/T Fluid Tem-
perature Sensor 2".
4.CHECK SUB-HARNESS
1. Disconnect park/neutral position switch connector and TCM connector.
2. Check continuity between park/neutral position switch connector
terminals and TCM connector 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 AT-122, "
Component Inspection".
OK or NG
OK >> GO TO 6.
NG >> Replace the A/T fluid temperature sensor 2. Refer to AT-210, "
Control Valve with TCM and A/T
Fluid Temperature Sensor 2".
6.CHECK TERMINAL CORD ASSEMBLY
Item name Condition °C (°F) Display value (Approx.)
ATF TEMP SE 1 0 (32) - 20 (68) - 80 (176) 3.3 - 2.7 - 09 V
PCIA0039E
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
PCIA0039E
Item Connector Terminal Continuity
Park/neutral position switch con-
nectorF505 6
Ye s
TCM connector F503 19
Park/neutral position switch con-
nectorF505 7
Ye s
TCM connector F503 18
SCIA5461E

AT-124
< SERVICE INFORMATION >
DTC P1721 VEHICLE SPEED SENSOR MTR
DTC P1721 VEHICLE SPEED SENSOR MTR
DescriptionINFOID:0000000003532336
The vehicle speed sensor·MTR signal is transmitted from combination meter to TCM by CAN communication
line. The signal functions as an auxiliary device to the revolution sensor when it is malfunctioning. The TCM
will then use the vehicle speed sensor·MTR signal.
CONSULT-II Reference Value in Data Monitor ModeINFOID:0000000003532337
On Board Diagnosis LogicINFOID:0000000003532338
• This is not an OBD-II self-diagnostic item.
• Diagnostic trouble code “P1721 VHE SPD SE·MTR” with CONSULT-II is detected when TCM does not
receive the proper vehicle speed sensor MTR signal (input by CAN communication) from combination meter.
Possible CauseINFOID:0000000003532339
Harness or connectors
(The sensor circuit is open or shorted.)
DTC Confirmation ProcedureINFOID:0000000003532340
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-II
1. Turn ignition switch “ON”. (Do not start engine.)
2. Select “DATA MONITOR” mode for “A/T” with CONSULT-II.
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 AT-124, "
Diagnosis Procedure".
Diagnosis ProcedureINFOID:0000000003532341
1.CHECK CAN COMMUNICATION LINE
Perform the self-diagnosis. Refer AT-83, "
CONSULT-II Function (A/T)".
Is a malfunction in the CAN communication indicated in the results?
YES >> Check CAN communication line. Refer to AT- 9 1.
NO >> GO TO 2.
2.CHECK INPUT SIGNAL
With CONSULT-II
Item name Condition Display value (km/h)
VHCL/S SE·MTR During driving Approximately matches the speedometer reading.
BCIA0031E

DTC P1721 VEHICLE SPEED SENSOR MTR
AT-125
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1. Start engine.
2. Select “ECU INPUT SIGNALS” in “DATA MONITOR” mode for
“A/T” with CONSULT-II.
3. Drive vehicle and read out the value of “VHCL/S SE·MTR”.
OK or NG
OK >> GO TO 4.
NG >> GO TO 3.
3.CHECK COMBINATION METERS
Check CAN communication line. Refer to DI-15, "
How to Proceed with Trouble Diagnosis".
OK or NG
OK >> GO TO 4.
NG >> Repair or replace damaged parts.
4.CHECK DTC
Perform “DTC Confirmation Procedure”.
• Refer to AT-124, "
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 AT-158
.
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 AT-210, "Control Valve with TCM and A/T Fluid Tem-
perature Sensor 2".
NG >> Repair or replace damaged parts.
Item name Condition Display value (Approx.)(km/h)
VHCL/S SE·MTR During drivingApproximately matches the speed-
ometer reading.
SCIA2148E