2004 INFINITI QX56 engine

AT-134
DTC P1716 TURBINE REVOLUTION SENSOR
Revision: August 20072004 QX56
DTC P1716 TURBINE REVOLUTION SENSORPFP:31935
DescriptionUCS002FC
The turbine revolution sensor detects input shaft rpm (revolutions per minute). It is located on the input side of
the automatic transmission. Monitors revolution of sensor 1 and sensor 2 for non-standard conditions.
CONSULT-II Reference ValueUCS002FD
On Board Diagnosis LogicUCS002FE

This is an OBD-II self-diagnostic item.

Diagnostic trouble code “TURBINE REV S/CIRC” with CONSULT-II or P1716 without CONSULT-II is
detected under the following conditions.
–When TCM does not receive the proper voltage signal from the sensor.
–When TCM detects an irregularity only at position of 4th gear for turbine revolution sensor 2.
Possible CauseUCS002FF

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

Turbine revolution sensor 1, 2
DTC Confirmation ProcedureUCS002FG
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.
VHCL SPEED SE: 40 km/h (25 MPH) or more
ENGINE SPEED: 1,500 rpm or more
ACCELE POS: 0.5/8 or more
Selector lever: “D” position
Gear position (Turbine revolution sensor 1): 4th or 5th posi-
tion
Gear position (Turbine revolution sensor 2): All 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-135, "
Diagnostic Procedure" .
WITH GST
Follow the procedure “With CONSULT-II”.
Item name Condition Display value (rpm)
TURBINE REV During driving (lock-up ON) Approximately matches the engine speed.
BCIA0030E

DTC P1716 TURBINE REVOLUTION SENSOR
AT-135
D
E
F
G
H
I
J
K
L
MA
B
AT
Revision: August 20072004 QX56
Diagnostic ProcedureUCS002FH
1. CHECK INPUT SIGNAL
With CONSULT-II
1. Start engine.
2. Select “ECU INPUT SIGNALS” in “DATA MONITOR” mode for
“A/T” with CONSULT-II.
3. Vehicle start and read out the value of “TURBINE REV”.
OK or NG
OK >> GO TO 6.
NG >> GO TO 2.
2. CHECK TCM
Perform TCM input/output signals inspection. Refer to AT-90, "
TCM Input/Output Signal Reference Values" .
OK or NG
OK >> GO TO 3.
NG >> GO TO 5.
3. CHECK DTC
Perform “DTC Confirmation Procedure”.

Refer to AT- 1 3 4 , "DTC Confirmation Procedure" .
OK or NG
OK >>INSPECTION END
NG >> GO TO 4.
4. DETECT MALFUNCTIONING ITEM
Check the following items:

The A/T assembly harness connector terminals for damage or loose connection with harness connector.
OK or NG
OK >> Replace the control valve with TCM. Refer to AT - 2 4 1 , "Control Valve With TCM and A/T Fluid
Temperature Sensor 2" .
NG >> Repair or replace damaged parts.
5. DETECT MALFUNCTIONING ITEM
Check the following items:

Power supply and ground circuit for TCM.

The A/T assembly harness connector terminals for damage or loose connection with harness connector.
OK or NG
OK >> GO TO 6.
NG >> Repair or replace damaged parts.
6. CHECK DTC
Perform “DTC Confirmation Procedure”.

Refer to AT- 1 3 4 , "DTC Confirmation Procedure" .
OK or NG
OK >>INSPECTION END
NG >> GO TO 2.
Item name Condition Display value (rpm)
TURBINE REV During driving (lock-up ON) Approximately matches the
engine speed.
PCIA0041E

AT-136
DTC P1721 VEHICLE SPEED SENSOR MTR
Revision: August 20072004 QX56
DTC P1721 VEHICLE SPEED SENSOR MTRPFP:24814
DescriptionUCS002FI
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 ValueUCS002FJ
On Board Diagnosis LogicUCS002FK

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

Diagnostic trouble code “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 CauseUCS002FL
Harness or connectors
(The sensor circuit is open or shorted.)
DTC Confirmation ProcedureUCS002FM
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-137, "
Diagnostic Procedure" .
Item name Condition Display value (Approx.) (km/h)
VHCL/S SE·MTR During driving Approximately matches the speedometer reading.
BCIA0030E

DTC P1721 VEHICLE SPEED SENSOR MTR
AT-137
D
E
F
G
H
I
J
K
L
MA
B
AT
Revision: August 20072004 QX56
Diagnostic ProcedureUCS002FN
1. CHECK CAN COMMUNICATION LINE
Perform the self-diagnosis. Refer AT-93, "
SELF-DIAGNOSTIC RESULT MODE" .
Is a malfunction in the CAN communication indicated in the results?
YES >> Check CAN communication line. Refer to AT- 1 0 3 , "DTC U1000 CAN COMMUNICATION LINE" .
NO >> GO TO 2.
2. CHECK INPUT SIGNAL
With CONSULT-II
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 METER
Check combination meter. Refer to DI-17, "
How to Proceed With Trouble Diagnosis"
OK or NG
OK >> GO TO 8.
NG >> Repair or replace damaged parts.
4. CHECK TCM
Perform TCM input/output signals inspection. Refer to AT-90, "
TCM Input/Output Signal Reference Values" .
OK or NG
OK >> GO TO 5.
NG >> GO TO 7.
5. CHECK DTC
Perform “DTC Confirmation Procedure”.

Refer to AT- 1 3 6 , "DTC Confirmation Procedure" .
OK or NG
OK >>INSPECTION END
NG >> GO TO 6.
6. DETECT MALFUNCTIONING ITEM
Check the following items:

The A/T assembly harness connector terminals for damage or loose connection with harness connector.
OK or NG
OK >> Replace the control valve with TCM. Refer to AT - 2 4 1 , "Control Valve With TCM and A/T Fluid
Temperature Sensor 2" .
NG >> Repair or replace damaged parts.
Item name Condition Display value (km/h)
VHCL/S SE·MTR During driving Approximately matches the
speedometer reading.
SCIA2148E

DTC P1730 A/T INTERLOCK
AT-139
D
E
F
G
H
I
J
K
L
MA
B
AT
Revision: August 20072004 QX56
DTC P1730 A/T INTERLOCKPFP:00000
DescriptionUCS002FO

Fail-safe function to detect interlock conditions.
On Board Diagnosis LogicUCS002FP

This is an OBD-II self-diagnostic item.

Diagnostic trouble code “A/T INTERLOCK” with CONSULT-II or P1730 without 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 CauseUCS002FQ

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

Low coast brake solenoid valve

ATF pressure switch 2
DTC Confirmation ProcedureUCS002FR
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 - 1 4 0 , "
Diagnostic Procedure" .
WITH GST
Follow the procedure “With CONSULT-II”.
BCIA0030E

AT-140
DTC P1730 A/T INTERLOCK
Revision: August 20072004 QX56
Judgement of A/T InterlockUCS002FS
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

: NG, X: OK
Diagnostic ProcedureUCS002FT
1. SELF-DIAGNOSIS
With CONSULT-II
1. Drive vehicle.
2. Stop vehicle and turn ignition switch “OFF”.
3. Turn ignition switch “ON”. (Do not start engine.)
4. Select “SELF-DIAG RESULTS” mode for “A/T” with CONSULT-
II.
OK or NG
OK >> GO TO 6.
NG >> Check low coast brake solenoid valve circuit and func-
tion. Refer to AT-169, "
DTC P1772 LOW COAST
BRAKE SOLENOID VALVE" , AT- 1 7 2 , "DTC P1774
LOW COAST BRAKE SOLENOID VALVE FUNCTION"
.
2. CHECK TCM
Perform TCM input/output signals inspection. Refer to AT- 9 0 , "
TCM Input/Output Signal Reference Values" .
OK or NG
OK >> GO TO 3.
NG >> GO TO 4.
3. CHECK DTC
Perform “DTC Confirmation Procedure”.

Refer to AT-139, "DTC Confirmation Procedure" .
OK or NG
OK >>INSPECTION END
NG >> GO TO 5.
Gear positionATF pressure switch output
Fail-safe
functionClutch pressure output pattern after fail-safe func-
tion
SW3
(I/C)SW6
(HLR/
C)SW5
(D/C)SW1
(Fr/B)SW2
(LC/B)I/C HLR/C D/C Fr/B LC/B L/U
A/T interlock
coupling pat-
tern3rd – X X –
Held in
2nd gearOFF OFF ON OFF OFF OFF
4th – X X –
Held in
2nd gearOFF OFF ON OFF OFF OFF
5th X X – X
Held in
2nd gearOFF OFF ON OFF OFF OFF
BCIA0031E

AT-142
DTC P1731 A/T 1ST ENGINE BRAKING
Revision: August 20072004 QX56
DTC P1731 A/T 1ST ENGINE BRAKINGPFP:00000
DescriptionUCS002FU
Fail-safe function to prevent sudden decrease in speed by engine brake other than at M1 position.
CONSULT-II Reference ValueUCS002FV
On Board Diagnosis LogicUCS002FW

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

Diagnostic trouble code “A/T 1ST E/BRAKING” with CONSULT-II is detected under the following condi-
tions.
–When TCM does not receive the proper voltage signal from the sensor.
–When TCM monitors each ATF pressure switch and solenoid monitor value, and detects as irregular when
engine brake of 1st gear acts other than at 1 position.
Possible CauseUCS002FX

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

Low coast brake solenoid valve

ATF pressure switch 2
DTC Confirmation ProcedureUCS002FY
NOTE:
If “DTC Confirmation Procedure” has been previously preformed, 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.
ENGINE SPEED: 1,200 rpm
Selector lever: “1” position
Gear position: 1st gear
5. If DTC is detected, go to AT-143, "
Diagnostic Procedure" .
Item name Condition Display value (ON-OFF display)
ON OFF SOLLow coast brake engaged. Refer to AT- 2 1
. ON
Low coast brake disengaged. Refer to AT- 2 1
. OFF
ATF PRES SW 2Low coast brake engaged. Refer to AT- 2 1
. ON
Low coast brake disengaged. Refer to AT- 2 1
. OFF
BCIA0030E

DTC P1731 A/T 1ST ENGINE BRAKING
AT-143
D
E
F
G
H
I
J
K
L
MA
B
AT
Revision: August 20072004 QX56
Diagnostic ProcedureUCS002FZ
1. CHECK INPUT SIGNALS
With CONSULT-II
1. Start the engine.
2. Select “ECU INPUT SIGNALS” or “MAIN SIGNALS” in “DATA
MONITOR” mode for “A/T” with CONSULT-II.
3. Drive vehicle in the “M” position (1st gear), and confirm the ON/
OFF actuation of the “ATF PRES SW 2”.
OK or NG
OK >> GO TO 6.
NG >> GO TO 2.
2. CHECK TCM
Perform TCM input/output signals inspection. Refer to AT-90, "
TCM Input/Output Signal Reference Values" .
OK or NG
OK >> GO TO 3.
NG >> GO TO 5.
3. CHECK DTC
Perform “DTC Confirmation Procedure”.

Refer to AT- 1 4 2 , "DTC Confirmation Procedure" .
OK or NG
OK >>INSPECTION END
NG >> GO TO 4.
4. DETECT MALFUNCTIONING ITEM
Check the following items:

The A/T assembly harness connector terminals for damage or loose connection with harness connector.
OK or NG
OK >> Replace the control valve with TCM. Refer to AT - 2 4 1 , "Control Valve With TCM and A/T Fluid
Temperature Sensor 2" .
NG >> Repair or replace damaged parts.
5. DETECT MALFUNCTIONING ITEM
Check the following items:

Power supply and ground circuit for TCM.

The A/T assembly harness connector terminals for damage or loose connection with harness connector.
OK or NG
OK >> GO TO 6.
NG >> Repair or replace damaged parts.
Item name Condition Display value
(ON-OFF display)
ON OFF
SOLLow coast brake engaged. Refer to AT- 2 1
.ON
Low coast brake disengaged. Refer to AT- 2 1
.OFF
ATF PRES
SW 2Low coast brake engaged. Refer to AT- 2 1
.ON
Low coast brake disengaged. Refer to AT- 2 1
.OFF
PCIA0067E