2007 INFINITI QX56 ESP

TROUBLE DIAGNOSIS
AT-59
< SERVICE INFORMATION >
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• Refer to AT-59, "Vehicle Speed When Shifting Gears".
With CONSULT-II
Read the gear position, throttle position and vehicle speed.
Does the A/T shift-up D2
→ D3 at the correct speed?
YES >> GO TO 4.
NO >> Enter a check mark at “Vehicle Does Not Shift: D2 → D3” on the diagnostics worksheet, then con-
tinue the road test.
4.CHECK SHIFT-UP D3 → D4 AND ENGINE BRAKE
When the transmission changes speed D3 → D4, return the accelerator pedal.
Does the A/T shift-up D3
→ D4 and apply the engine brake?
YES >> 1. Stop the vehicle.
2. See AT-59, "
Cruise Test - Part 3".
NO >> Enter a check mark at “Vehicle Does Not Shift: D3 → D4” on the diagnostics worksheet, then con-
tinue the road test.
Cruise Test - Part 3INFOID:0000000003532253
1.CHECK SHIFT-DOWN
During D
5 driving, move gear selector from D → 4 → 3 → 2 → 1.
With CONSULT-II
Read the gear position.
Is downshifting correctly performed?
YES >> GO TO 2.
NO >> Enter a check mark at “Vehicle does not shift” at the corresponding position (5th → 4th, 4th → 3rd,
3rd → 2nd, 2nd → 1st) on the diagnostics worksheet, then continue the road test.
2.CHECK ENGINE BRAKE
Does engine braking effectively reduce speed in 1
1 position?
YES >> 1. Stop the vehicle.
2. Carry out the self-diagnostics. Refer to AT-83, "
CONSULT-II Function (A/T)".
NO >> Enter a check mark at “Vehicle Does Not Decelerate By Engine Brake” on the diagnostics work-
sheet, then continue trouble diagnosis.
Vehicle Speed When Shifting GearsINFOID:0000000003532254
NORMAL MODE
• At half throttle, the accelerator opening is 4/8 of the full opening.
TOW MODE
Final
gear
ratioThrottle positionVehicle speed km/h (MPH)
D
1 →D2D2 →D3D3 →D4D4 →D5D5 →D4D4 →D3D3 →D2D2 →D1
2.937Full throttle 70 - 74
(44 - 46)112 - 120
(70 - 75)176 - 186
(110 - 116)249 - 259
(155 - 161)245 - 255
(152 - 159)166 - 176
(103 - 110)100 - 108
(62 - 67)43 - 47
(27 - 30)
Half throttle 46 - 50
(28 - 31)74 - 82
(46 - 51)103 - 113
(64 - 70)135 - 145
(84 - 90)109 - 119
(68 - 74)69 - 79
(43 - 49)44 - 52
(27 - 32)11 - 1 5
(7 - 10)
3.357Full throttle 61 - 65
(38 - 41)97 - 105
(61 - 66)153 - 163
(95 - 102)236 - 246
(147 - 153)232 - 242
(144 - 151)143 - 153
(89 - 95)87 - 95
(54 - 59)43 - 47
(27 - 29)
Half throttle 41 - 45
(26 - 28)66 - 74
(41 - 46)89 - 99
(56 - 62)11 7 - 1 2 7
(73 - 79)95 - 105
(59 - 65)59 - 69
(37 - 43)38 - 46
(24 - 29)11 - 1 5
(7 - 10)
Final
gear
ratioThrottle positionVehicle speed km/h (MPH)
D
1 →D2D2 →D3D3 →D4D4 →D5D5 →D4D4 →D3D3 →D2D2 →D1

DTC P0720 VEHICLE SPEED SENSOR A/T (REVOLUTION SENSOR)
AT-105
< SERVICE INFORMATION >
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DTC P0720 VEHICLE SPEED SENSOR A/T (REVOLUTION SENSOR)
DescriptionINFOID:0000000003532291
The revolution sensor detects the revolution of the idler gear parking pawl lock gear and emits a pulse signal.
The pulse signal is sent to the TCM which converts it into vehicle speed.
CONSULT-II Reference Value in Data Monitor ModeINFOID:0000000003532292
On Board Diagnosis LogicINFOID:0000000003532293
• This is an OBD-II self-diagnostic item.
• Diagnostic trouble code “P0720 VEH SPD SEN/CIR AT” with CONSULT-II is detected under the following
conditions.
- When TCM does not receive the proper voltage signal from the sensor.
- After ignition switch is turned “ON”, irregular signal input from vehicle speed sensor MTR before the vehicle
starts moving.
Possible CauseINFOID:0000000003532294
• Harness or connectors
(The sensor circuit is open or shorted.)
• Revolution sensor
• Vehicle speed sensor MTR
DTC Confirmation ProcedureINFOID:0000000003532295
CAUTION:
• Always drive vehicle at a safe speed.
• Be careful not to rev engine into the red zone on the tachometer.
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. Drive vehicle and check for an increase of “VHCL/S SE·A/T”
value in response to “VHCL/S SE·MTR” value.
If the check result is NG, go to AT-107, "
Diagnosis Procedure".
If the check result is OK, go to following step.
4. Select “DATA MONITOR” mode for “ENGINE” with CONSULT-II.
5. Start engine and maintain the following conditions for at least 5
consecutive seconds.
VHCL SPEED SE: 30 km/h (19 MPH) or more
THRTL POS SEN: More than 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.
If the check result is NG, go to AT-107, "
Diagnosis Procedure".
If the check result is OK, go to following step.
6. Maintain the following conditions for at least 5 consecutive seconds.
ENGINE SPEED: 3,500 rpm or more
THRTL POS SEN: More than 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.
Item name Condition Display value (km/h)
VHCL/S SE·A/T During driving Approximately matches the speedometer 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
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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

DTC P0745 LINE PRESSURE SOLENOID VALVE
AT-115
< SERVICE INFORMATION >
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DTC P0745 LINE PRESSURE SOLENOID VALVE
DescriptionINFOID:0000000003532316
The line pressure solenoid valve regulates the oil pump 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 pressure, the accelerator (throttle) should be open until
the closed throttle position signal is “OFF”.
CONSULT-II Reference Value in Data Monitor ModeINFOID:0000000003532317
On Board Diagnosis LogicINFOID:0000000003532318
• This is an OBD-II self-diagnostic item.
• Diagnostic trouble code “P0745 L/PRESS SOL/CIRC” with CONSULT-II is detected under the following con-
ditions.
- 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:0000000003532319
• Harness or connectors
(The solenoid circuit is open or shorted.)
• Line pressure solenoid valve
DTC Confirmation ProcedureINFOID:0000000003532320
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
“ENGINE” with CONSULT-II.
2. Engine start and wait at least 5 second.
3. If DTC is detected, go to AT-115, "
Diagnosis Procedure".
WITH GST
Follow the procedure “With CONSULT-II”.
Diagnosis ProcedureINFOID:0000000003532321
1.CHECK INPUT SIGNAL
With CONSULT-II
Item name Condition Display value (Approx.)
LINE PRES SOL During driving 0.2 - 0.6 A
BCIA0031E

AT-126
< SERVICE INFORMATION >
DTC P1730 A/T INTERLOCK
DTC P1730 A/T INTERLOCK
DescriptionINFOID:0000000003532342
• Fail-safe function to detect interlock conditions.
On Board Diagnosis LogicINFOID:0000000003532343
• This is an OBD-II self-diagnostic item.
• Diagnostic trouble code “P1730 A/T INTERLOCK” with CONSULT-II is detected when TCM does not receive
the proper voltage 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:0000000003532344
• Harness or connectors
(The solenoid and switch circuit is open or shorted.)
• Low coast brake solenoid valve
• ATF pressure switch 2
DTC Confirmation ProcedureINFOID:0000000003532345
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.
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 AT-127, "
Diagnosis Procedure".
WITH GST
Follow the procedure “With CONSULT-II”.
Judgement of A/T InterlockINFOID:0000000003532346
When A/T Interlock is judged to be malfunctioning, the vehicle should be fixed in 2nd gear, and should be set
in a condition in which it can travel.
When one of the following fastening patterns is detected, the fail-safe function in correspondence with the indi-
vidual pattern should be performed.
A/T INTERLOCK COUPLING PATTERN TABLE
BCIA0031E

AT-130
< SERVICE INFORMATION >
DTC P1752 INPUT CLUTCH SOLENOID VALVE
DTC P1752 INPUT CLUTCH SOLENOID VALVE
DescriptionINFOID:0000000003532354
Input clutch solenoid valve is controlled by the TCM in response to signals sent from the PNP switch, vehicle
speed sensor and accelerator pedal position sensor (throttle position sensor). Gears will then be shifted to the
optimum position.
CONSULT-II Reference Value in Data Monitor ModeINFOID:0000000003532355
On Board Diagnosis LogicINFOID:0000000003532356
• This is an OBD-II self-diagnostic item.
• Diagnostic trouble code “P1752 I/C SOLENOID/CIRC” with CONSULT-II is detected under the following con-
ditions.
- 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:0000000003532357
• Harness or connectors
(The solenoid circuit is open or shorted.)
• Input clutch solenoid valve
DTC Confirmation ProcedureINFOID:0000000003532358
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.
4. Drive vehicle and maintain the following conditions for at least 5
consecutive seconds.
ACCELE POS: 1.5/8 - 2.0/8
Selector lever: “D” position
Gear position: 3rd ⇒ 4th Gear (I/C ON/OFF)
Driving location: Driving the vehicle uphill (increased
engine load) will help maintain the driving conditions
required for this test.
5. If DTC is detected go to AT-130, "
Diagnosis Procedure".
WITH GST
Follow the procedure “With CONSULT-II”.
Diagnosis ProcedureINFOID:0000000003532359
1.CHECK INPUT SIGNAL
With CONSULT-II
Item name Condition Display value (Approx.)
I/C SOLENOIDInput clutch disengaged. Refer to AT- 2 0
. 0.6 - 0.8 A
Input clutch engaged. Refer to AT- 2 0
.0 - 0.05 A
BCIA0031E

AT-132
< SERVICE INFORMATION >
DTC P1754 INPUT CLUTCH SOLENOID VALVE FUNCTION
DTC P1754 INPUT CLUTCH SOLENOID VALVE FUNCTION
DescriptionINFOID:0000000003532360
• Input clutch solenoid valve is controlled by the TCM in response to signals sent from the PNP switch, vehicle
speed sensor and accelerator pedal position sensor (throttle position sensor). Gears will then be shifted to
the optimum position.
• 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.
CONSULT-II Reference Value in Data Monitor ModeINFOID:0000000003532361
On Board Diagnosis LogicINFOID:0000000003532362
• This is an OBD-II self-diagnostic item.
• Diagnostic trouble code “P1754 I/C SOLENOID FNCTN” with CONSULT-II is detected under the following
conditions.
- When TCM detects that actual gear ratio is irregular, and relation between gear position and condition of
pressure switch 3 is irregular during depressing accelerator pedal. (Other than during shift change)
- When TCM detects that relation between gear position and condition of ATF pressure switch 3 is irregular
during releasing accelerator pedal. (Other than during shift change)
Possible CauseINFOID:0000000003532363
• Harness or connectors
(The solenoid and switch circuits are open or shorted.)
• Input clutch solenoid valve
• ATF pressure switch 3
DTC Confirmation ProcedureINFOID:0000000003532364
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. Start engine.
2. Accelerate vehicle to maintain the following conditions.
ACCELE POSI: 1.5/8 - 2.0/8
Selector lever: “D” position
Gear position: 3rd ⇒ 4th Gear (I/C ON/OFF)
Driving location: Driving the vehicle uphill (increased
engine load) will help maintain the driving conditions
required for this test.
3. Perform step “2” again.
4. Turn ignition switch “OFF”, then perform step “1” to “3” again.
5. Check “SELF-DIAG RESULTS” mode for “A/T” with CONSULT-
II. If DTC (P1754) is detected, refer to AT-133, "
Diagnosis Pro-
cedure".
If DTC (P1752) is detected, go to AT-133, "
Diagnosis Procedure".
If DTC (P1843) is detected, go to AT-152, "
Diagnosis Procedure".
Item name Condition Display value (Approx.)
I/C SOLENOIDInput clutch disengaged. Refer to AT- 2 0
. 0.6 - 0.8 A
Input clutch engaged. Refer to AT- 2 0
.0 - 0.05 A
ATF PRES SW 3Input clutch engaged. Refer to AT- 2 0
.ON
Input clutch disengaged. Refer to AT- 2 0
.OFF
BCIA0031E