2005 INFINITI QX4 check engine

DTC P0725 ENGINE SPEED SIGNAL
AT-113
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Revision: October 20052005 QX56
DTC P0725 ENGINE SPEED SIGNALPFP:24825
DescriptionECS00CFH
The engine speed signal is sent from the ECM to the TCM.
CONSULT-II Reference ValueECS00CFI
On Board Diagnosis LogicECS0 0CF J

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 CauseECS00CFK
Harness or connectors
(The ECM to the TCM circuit is open or shorted.)
DTC Confirmation ProcedureECS00CFL
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 - 11 3 , "
Diagnostic Procedure" .
Diagnostic ProcedureECS0 0CF M
1. CHECK CAN COMMUNICATION LINE
Perform the self-diagnosis. Refer to AT - 8 5 , "
SELF-DIAGNOSTIC RESULT MODE" .
Is a malfunction in the CAN communication indicated in the results?
YES >> Check CAN communication line. Refer to AT- 9 5 , "DTC U1000 CAN COMMUNICATION LINE" .
NO >> GO TO 2.
Item name Condition Display value (rpm)
ENGINE SPEED Engine running Closely matches the tachometer reading.
BCIA0030E

AT-114
DTC P0725 ENGINE SPEED SIGNAL
Revision: October 20052005 QX56
2. CHECK DTC WITH TCM
With CONSULT-II
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-619, "IGNITION SIGNAL" .
3. CHECK DTC
Perform "DTC Confirmation Procedure".

Refer to AT-113, "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- 1 6 8 , "
MAIN POWER SUPPLY AND GROUND CIR-
CUIT" .
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 connec-
tor.
OK or NG
OK >> Replace the control valve with TCM. Refer to AT-231, "Control Valve With TCM and A/T Fluid
Temperature Sensor 2" .
NG >> Repair or replace damaged parts.
Item name Condition Display value (rpm)
ENGINE SPEED Engine running Closely matches the tachometer reading.
PCIA0041E

AT-116
DTC P0740 TORQUE CONVERTER CLUTCH SOLENOID VALVE
Revision: October 20052005 QX56
Diagnostic ProcedureECS00CFS
1. CHECK INPUT SIGNAL
With CONSULT-II
1. Turn ignition switch “ON”.
2. Select “MAIN SIGNALS” in “DATA MONITOR” mode for “A/T”
with CONSULT-II.
3. Start 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 AT- 1 6 8 , "
MAIN POWER SUPPLY AND GROUND CIR-
CUIT" .
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 connec-
tor.
OK or NG
OK >> Replace the control valve with TCM. Refer to AT-231, "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 AT-115, "DTC Confirmation Procedure" .
OK or NG
OK >>INSPECTION END
NG >> GO TO 2.
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
SCIA4793E

DTC P0744 A/T TCC S/V FUNCTION (LOCK-UP)
AT-117
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Revision: October 20052005 QX56
DTC P0744 A/T TCC S/V FUNCTION (LOCK-UP)PFP:31940
DescriptionECS00CFT
This malfunction is detected when the A/T does not shift into 5th gear position or the torque converter clutch
does not lock-up as instructed by the 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,
etc.
CONSULT-II Reference ValueECS00CFU
On Board Diagnosis LogicECS00CFV

This is an OBD-II self-diagnostic item.

Diagnostic trouble code “P0744 A/T TCC S/V FNCTN” with CONSULT-II 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 CauseECS00CFW

Harness or connectors
(The solenoid circuit is open or shorted.)

Torque converter clutch solenoid valve

Hydraulic control circuit
DTC Confirmation ProcedureECS00CFX
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 and Select “TCC S/V FNCTN CHECK” of “DTC
WORK SUPPORT” mode for “A/T” with CONSULT-II 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 AT- 3 2 2 , "Vehicle Speed When Performing and Releasing Complete
Lock-up" .
–If “TESTING” does not appear on CONSULT-II 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 displayed. (If “NG” is displayed, refer to “DIAGNOSTIC PROCEDURE”.)
Refer to AT- 11 8 , "
Diagnostic Procedure" .
Refer to shift schedule, AT-322, "
Vehicle Speed When Performing and Releasing Complete Lock-up" .
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
BCIA0030E

AT-118
DTC P0744 A/T TCC S/V FUNCTION (LOCK-UP)
Revision: October 20052005 QX56
WITH GST
Follow the procedure “With CONSULT-II”.
Diagnostic ProcedureECS00CFY
1. CHECK INPUT SIGNAL
With CONSULT-II
1. Turn ignition switch “ON”.
2. Select “MAIN SIGNALS” in “DATA MONITOR” mode for “A/T”
with CONSULT-II.
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 AT- 1 6 8 , "
MAIN POWER SUPPLY AND GROUND CIR-
CUIT" .
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 connec-
tor.
OK or NG
OK >> Replace the control valve with TCM. Refer to AT-231, "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 AT-117, "DTC Confirmation Procedure" .
OK or NG
OK >>INSPECTION END
NG >> GO TO 2.
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
SCIA4793E

AT-120
DTC P0745 LINE PRESSURE SOLENOID VALVE
Revision: October 20052005 QX56
Diagnostic ProcedureECS00CG4
1. CHECK INPUT SIGNAL
With CONSULT-II
1. Turn ignition switch “ON”.
2. Select “MAIN SIGNALS” in “DATA MONITOR” mode for “A/T”
with CONSULT-II.
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
Check TCM power supply and ground circuit. Refer to AT- 1 6 8 , "
MAIN POWER SUPPLY AND GROUND CIR-
CUIT" .
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 connec-
tor.
OK or NG
OK >> Replace the control valve with TCM. Refer to AT-231, "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 AT-119, "DTC Confirmation Procedure" .
OK or NG
OK >>INSPECTION END
NG >> GO TO 2.
Item name Condition Display value (Approx.)
LINE PRES SOL During driving 0.2 - 0.6 A
SCIA4793E

DTC P1702 TRANSMISSION CONTROL MODULE (RAM)
AT-121
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Revision: October 20052005 QX56
DTC P1702 TRANSMISSION CONTROL MODULE (RAM)PFP:31036
DescriptionECS00CG5
The TCM consists of a microcomputer and connectors for signal input and output and for power supply. The
TCM controls the A/T.
On Board Diagnosis LogicECS00CG6

This is not an OBD-II self-diagnostic item.

Diagnostic trouble code “P1702 TCM·RAM” with CONSULT-II is detected when TCM memory RAM is
malfunctioning.
Possible CauseECS00CG7
TCM.
DTC Confirmation ProcedureECS00CG8
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. Run engine for at least 2 consecutive seconds at idle speed.
5. If DTC is detected, go to AT - 1 2 1 , "
Diagnostic Procedure" .
Diagnostic ProcedureECS00CG9
1. CHECK DTC
With CONSULT-II
1. Turn ignition switch “ON”. (Do not start engine.)
2. Select “SELF-DIAG RESULTS” mode for “A/T” with CONSULT-
II.
3. Touch “ERASE”.
4. Turn ignition switch “OFF” and wait at least 10 seconds.
5. Perform “DTC Confirmation Procedure”, AT-121, "
DTC Confir-
mation Procedure" .
Is the
“TCM·RAM” displayed again?
YES >> Replace the control valve with TCM. Refer to AT-231,
"Control Valve With TCM and A/T Fluid Temperature
Sensor 2" .
NO >>INSPECTION END
BCIA0030E
BCIA0031E

AT-122
DTC P1703 TRANSMISSION CONTROL MODULE (ROM)
Revision: October 20052005 QX56
DTC P1703 TRANSMISSION CONTROL MODULE (ROM)PFP:31036
DescriptionECS00CGA
The TCM consists of a microcomputer and connectors for signal input and output and for power supply. The
TCM controls the A/T.
On Board Diagnosis LogicECS00CGB

This is not an OBD-II self-diagnostic item.

Diagnostic trouble code “P1703 TCM·ROM” with CONSULT-II is detected when TCM memory ROM is
malfunctioning.
Possible CauseECS00CGC
TCM.
DTC Confirmation Procedure ECS00CGD
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 to “ON”. (Do not start engine.)
2. Select “DATA MONITOR” mode for A/T with CONSULT-II.
3. Start engine.
4. Run engine for at least 2 consecutive seconds at idle speed.
5. If DTC is detected, go to AT-122, "
Diagnostic Procedure" .
Diagnostic ProcedureECS00CGE
1. CHECK DTC
With CONSULT-II
1. Turn ignition switch “ON”. (Do not start engine.)
2. Select “SELF-DIAG RESULTS” mode for “A/T” with CONSULT-
II.
3. Touch “ERASE”.
4. Turn ignition switch “OFF” and wait at least 10 seconds.
5. Perform “DTC Confirmation Procedure”, AT-122, "
DTC Confir-
mation Procedure" .
Is the
“TCM·ROM” displayed again?
YES >> Replace the control valve with TCM. Refer to AT-231,
"Control Valve With TCM and A/T Fluid Temperature
Sensor 2" .
NO >>INSPECTION END
BCIA0030E
BCIA0031E