Ins INFINITI QX56 2004 Factory Owners Manual

AT-128
DTC P1703 TRANSMISSION CONTROL MODULE (ROM)
Revision: August 20072004 QX56
DTC P1703 TRANSMISSION CONTROL MODULE (ROM)PFP:31036
DescriptionUCS002EU
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 LogicUCS002EV

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

Diagnostic trouble code “TCM·ROM” with CONSULT-II is detected when TCM memory ROM is malfunc-
tioning.
Possible CauseUCS002EW
TCM.
DTC Confirmation Procedure UCS002EX
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-128, "
Diagnostic Procedure" .
Diagnostic ProcedureUCS002EY
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-128, "
DTC Confir-
mation Procedure" .
Is the
“TCM·ROM” displayed again?
YES >> Replace the control valve with TCM. Refer to AT-241,
"Control Valve With TCM and A/T Fluid Temperature
Sensor 2" .
NO >>INSPECTION END
BCIA0030E
BCIA0031E

AT-130
DTC P1705 THROTTLE POSITION SENSOR
Revision: August 20072004 QX56
2. CHECK DTC WITH TCM
With CONSULT-II
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 “ACCLE
POSI” and “THROTTLE POSI”.
Check engine speed changes according to throttle position.
4. Select “SELF-DIAG RESULTS” mode for “A/T” with CONSULT-II. Refer to AT- 9 3 , "
SELF-DIAGNOSTIC
RESULT MODE" .
With GST
Follow the procedure “With CONSULT-II”.
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 EC-103, "
CONSULT-II Function" .
With GST
Follow the procedure “With CONSULT-II”.
OK or NG
OK >> GO TO 4.
NG >> Check the DTC detected item. Refer to EC-103, "
CON-
SULT-II Function" .

If CAN communication line is detected, go to AT-103,
"DTC U1000 CAN COMMUNICATION LINE" .
4. CHECK DTC
Perform “DTC Confirmation Procedure”.

Refer to AT-129, "DTC Confirmation Procedure" .
OK or NG
OK >>INSPECTION END
NG >> Replace the control valve with TCM. Refer to AT-241, "
Control Valve With TCM and A/T Fluid
Temperature Sensor 2" .
Item name Condition Display value
(Approx.)
ACCLE POSIReleased accelerator pedal. 0.0/8
Fully depressed accelerator pedal. 8/8
THROTTLE POSIReleased accelerator pedal. 0.0/8
Fully depressed accelerator pedal. 8/8
PCIA0070E
BCIA0031E

AT-132
DTC P1710 A/T FLUID TEMPERATURE SENSOR CIRCUIT
Revision: August 20072004 QX56
Diagnostic ProcedureUCS002FA
1. CHECK A/T FLUID TEMPERATURE SENSOR 1 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 1”.
OK or NG
OK >> GO TO 2.
NG >> GO TO 4.
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 3.
3. CHECK A/T FLUID TEMPERATURE SENSOR 2
Check A/T fluid temperature sensor 2. Refer to AT-133, "
Component Inspection" .
OK or NG
OK >> GO TO 4.
NG >> Replace the A/T fluid temperature sensor 2. Refer to AT-249, "
A/T FLUID TEMPERATURE SEN-
SOR 2 REMOVAL AND INSTALLATION" .
4. 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 5.
NG >> GO TO 7.
5. CHECK DTC
Perform “DTC Confirmation Procedure”.

Refer to AT-131, "DTC Confirmation Procedure" .
OK or NG
OK >>INSPECTION END
NG >> GO TO 6.
Item name Condition °C (°F) Display value (Approx.)
ATF TEMP SE 1 0 (32) - 20 (68) - 80 (176) 3.2 - 2.5 - 0.8 V
PCIA0039E
Item name Condition °C (°F) Display value (Approx.)
ATF TEMP SE 2 0 (32) - 20 (68) - 80 (176) 3.2 - 2.4 - 0.65 V
PCIA0039E

DTC P1710 A/T FLUID TEMPERATURE SENSOR CIRCUIT
AT-133
D
E
F
G
H
I
J
K
L
MA
B
AT
Revision: August 20072004 QX56
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.
7. 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 8.
NG >> Repair or replace damaged parts.
8. CHECK DTC
Perform “DTC Confirmation Procedure”.

Refer to AT- 1 3 1 , "DTC Confirmation Procedure" .
OK or NG
OK >>INSPECTION END
NG >> GO TO 4.
Component InspectionUCS002FB
A/T FLUID TEMPERATURE SENSOR 2
1. Remove A/T fluid temperature sensor 2. Refer to AT-249, "A/T FLUID TEMPERATURE SENSOR 2
REMOVAL AND INSTALLATION" .
2. Check resistance between terminals. Refer to AT - 3 3 2 , "
A/T Fluid Temperature Sensor" .
Temperature °C (°F) Resistance (KΩ) (Approx.)
0 (32) 10
20 (68) 4
80 (176) 0.5

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

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

AT-138
DTC P1721 VEHICLE SPEED SENSOR MTR
Revision: August 20072004 QX56
7. DETECT MALFUNCTIONING ITEM
Check the following items:

Power supply and ground circuit for TCM.

The A/T assembly harness connector pin terminals for damage or loose connection with harness connec-
tor.
OK or NG
OK >> GO TO 8.
NG >> Repair or replace damaged parts.
8. CHECK DTC
Perform “DTC Confirmation Procedure”.

Refer to AT-136, "DTC Confirmation Procedure" .
OK or NG
OK >>INSPECTION END
NG >> GO TO 4.

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

DTC P1730 A/T INTERLOCK
AT-141
D
E
F
G
H
I
J
K
L
MA
B
AT
Revision: August 20072004 QX56
4. DETECT MALFUNCTIONING ITEM
Check the following items:

Power supply and ground circuit for TCM.

The A/T assembly harness connector pin terminals for damage or loose connection with harness connec-
tor.
OK or NG
OK >> GO TO 6.
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 - 2 4 1 , "Control Valve With TCM and A/T Fluid
Temperature Sensor 2" .
NG >> Repair or replace damaged parts.
6. CHECK DTC
Perform “DTC Confirmation Procedure”.

Refer to AT- 1 3 9 , "DTC Confirmation Procedure" .
OK or NG
OK >>INSPECTION END
NG >> GO TO 2.

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