speed sensor transmission INFINITI QX56 2004 Factory Owner's Manual

EC-544Revision: August 2007
DTC P1574 ASCD VEHICLE SPEED SENSOR
2004 QX56
DTC P1574 ASCD VEHICLE SPEED SENSORPFP:31036
Component DescriptionUBS00HBM
The ECM receives two vehicle speed sensor signals via CAN communication line. One is sent from combina-
tion meter and the other is from TCM (Transmission control module). The ECM uses these signals for ASCD
control. Refer to EC-647, "
AUTOMATIC SPEED CONTROL DEVICE (ASCD)" for ASCD functions.
On Board Diagnosis LogicUBS00HBN
This self-diagnosis has the one trip detection logic.
The MIL will not light up for this diagnosis.
NOTE:

If DTC P1574 is displayed with DTC U1000, U1001, first perform the trouble diagnosis for DTC
U1000, U1001. Refer to EC-135, "
DTC U1000, U1001 CAN COMMUNICATION LINE" .

If DTC P1574 is displayed with DTC P0500, first perform the trouble diagnosis for DTC P0500.
Refer to EC-340, "
DTC P0500 VSS".

If DTC P1574 is displayed with DTC P0605, first perform the trouble diagnosis for DTC P0605.
Refer to EC-351, "
DTC P0605 ECM".
DTC Confirmation ProcedureUBS00HBO
CAUTION:
Always drive vehicle at a safe speed.
NOTE:
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
TESTING CONDITION:
Step 3 may be conducted with the drive wheels lifted in the shop or by driving the vehicle. If a road test
is expected to be easier, it is unnecessary to lift the vehicle.
WITH CONSULT-II
1. Start engine (VDC switch OFF).
2. Select “DATA MONITOR” mode with CONSULT-II.
3. Drive the vehicle at more than 40 km/h (25 MPH).
4. If DTC is detected, go to EC-545, "
Diagnostic Procedure" .
WITH GST
Follow the procedure “WITH CONSULT-II” above.
DTC No.Trouble Diagnosis
NameDTC Detecting Condition Possible Cause
P1574
1574ASCD vehicle speed
sensorECM detects a difference between two vehicle
speed signals is out of the specified range.

Harness or connectors
(The CAN communication line is open or
shorted.)

Combination meter

ABS actuator and electric unit (control unit)

Wheel sensor

TCM

ECM
SEF 0 58 Y

TERMINOLOGY
GI-53
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Revision: August 20072004 QX56
***: Not applicableTransmission control module TCM A/T control unit
Turbocharger TC Turbocharger
Vehicle speed sensor VSS Vehicle speed sensor
Volume air flow sensor VAFS Air flow meter
Warm up oxidation catalyst WU-OC Catalyst
Warm up oxidation catalytic converter sys-
temWU-OC system ***
Warm up three way catalyst WU-TWC Catalyst
Warm up three way catalytic converter sys-
temWU-TWC system ***
Wide open throttle position switch WOTP switch Full switchNEW TERMNEW ACRONYM /
ABBREVIATIONOLD TERM

IDX-2
ALPHABETICAL INDEX
Numerics
2-4WD shift solenoid valve ................................ TF-95
4LO indicator lamp ............................................. TF-90
4WD shift indicator lamp .................................... TF-85
4WD shift switch ................................................ TF-95
4WD solenoid valve ........................................... TF-95
4WD warning lamp ............................................ TF-13
A
A/C air flow ...................................................... ATC-29
A/C compressor clutch removal and installation .. ATC-
167
A/C compressor mounting ............................. ATC-166
A/C compressor precaution ............................. ATC-11
A/C compressor special service tool ................ ATC-14
A/C control operation (auto A/C) ...................... ATC-26
A/C diagnostic work flow (auto A/C) .............. ATC-120
A/C evaporator ............................................... ATC-175
A/C HFC134a (R134a) system identification ..... ATC-7
A/C HFC134a (R134a) system precaution ........ ATC-5
A/C HFC134a (R134a) system service procedure ATC-
162
A/C HFC134a (R134a) system service tools ... ATC-14
A/C HFC134a system service equipment precaution ...
ATC-11
A/C lubricant (R134a) ...................................... ATC-22
A/C lubrication oil ............................................. ATC-22
A/C operational check ....................... ATC-56, ATC-59
A/C self-diagnoses (auto A/C) ........ ATC-53, ATC-120
A/C service data specification ........................ ATC-182
A/C trouble diagnoses (auto A/C) .................... ATC-33
A/C, A - Wiring diagram ................................... ATC-41
A/T - Wiring diagram .......................................... AT-52
A/T fluid checking ...................... AT-13, AT-58, MA-21
A/T fluid cooler cleaning .................................... AT-15
A/T fluid replacement ............................. AT-13, MA-23
A/T fluid temperature sensor ........................... AT-131
A/T IND - Wiring diagram .................................... DI-41
A/T indicator ........................................................ DI-41
A/T shift lock system ........................................ AT-236
A/T trouble diagnoses ........................................ AT-43
ABS - Wiring diagram ..................................... BRC-16
ABS (anti-lock brake system) ........................... BRC-7
Accelerator control system ............................... ACC-2
Accelerator pedal position (APP) sensor . EC-556, EC-
562, EC-576
Accelerator pedal released position learning ..... EC-44
AF1B1-Wiring diagram EC-431, EC-439, EC-447, EC-
456, EC-466, EC-475, EC-487
AF1B2-Wiring diagram EC-433, EC-441, EC-449, EC-
458, EC-468, EC-477, EC-489
AF1HB1-Wiring diagram .................................. EC-355
AF1HB2-Wiring diagram .................................. EC-357
Aiming adjustment .................................. LT-31, LT-78
Air bag .............................................................. SRS-3
Air cleaner and air duct ..................................... EM-14
Air cleaner filter replacement ............................ MA-15
Air conditioner cut control ................................. EC-30
Air flow meter - See Mass air flow sensor EC-146, EC-
154
Air fuel ratio sensor 1 .. EC-429, EC-437, EC-445, EC-
454, EC-463, EC-472, EC-484
Air fuel ratio sensor 1 heater ........................... EC-354
Air mix. door motor .......................................... ATC-67
All - mode 4WD system ..................................... TF-10
Ambient sensor ............................. ATC-125, ATC-136
Angular tightening application ............................. EM-3
APPS1 - Wiring diagram ................................. EC-558
APPS2 - Wiring diagram ................................. EC-564
APPS3 - Wiring diagram ................................. EC-578
ASC/BS - Wiring diagram ............................... EC-536
ASC/SW - Wiring diagram .............................. EC-519
ASCBOF - Wiring diagram .............................. EC-622
ASCD .............................................................. EC-647
ASCD (automatic speed control device) ........... ACS-3
ASCD brake switch ........................... EC-534, EC-621
ASCD indicator lamp ....................................... EC-628
ASCD steering switch ..................................... EC-517
ASCIND - Wiring diagram ............................... EC-629
ATP switch ......................................................... TF-96
ATP warning lamp .............................................. TF-89
AUDIO - Wiring diagram .................................... AV-10
AUT/DP - Wiring diagram .................................. SE-19
Auto air conditioner - Wiring diagram .............. ATC-41
Auto anti-dazzling inside mirror ........... GW-76, GW-77
Autolamp ............................................................ LT-47
Automatic amplifier ......................................... ATC-60
Automatic transmission number .......................... GI-48
AV and NAVI control unit ................................... AV-63
AV communication line ...................................... AV-87
B
Back door trim ..................................................... EI-31
Back sonar .......................................................... DI-59
BACK/L - Wiring diagram ................................. LT-106
Back-up lamp ................................................... LT-106
Ball joint (front) ................................................ FSU-15
Basic inspection ................................................ EC-79
Battery ................................................................. SC-4
Battery/Starting/Charging System Tester SC-6, SC-12,
SC-19
BCM (Body control module) .............................. BCS-3
Block heater ...................................................... EM-73
Blower motor ................................... ATC-83, ATC-140
Body alignment ................................................ BL-174
Body component parts ..................................... BL-161
Body construction ............................................ BL-173
Body exterior paint color .................................. BL-160
Body mounting ................................................. BL-159
Body repair ....................................................... BL-160
Body sealing .................................................... BL-170
Brake booster .................................................... BR-17
Brake fluid level ................................................. MA-27
Brake hydraulic line ........................................... BR-12
Brake inspection ............................................... MA-28

IDX-8
ALPHABETICAL INDEX
Torque convertor clutch solenoid valve ... AT-118, AT-
121
Tow truck towing ................................................. GI-42
Towing point ....................................................... GI-43
TPS1 - Wiring diagram .................................... EC-238
TPS2 - Wiring diagram .................................... EC-173
TPS3 - Wiring diagram .................................... EC-571
Traction control system - Wiring diagram ....... BRC-16
Transfer control device .................................... TF-104
Transfer control unit inspection table ................. TF-55
Transfer dropping resistor .................................. TF-96
Transfer fluid temperature sensor ...................... TF-95
Transfer motor ................................................. TF-106
Transfer motor relay .......................................... TF-97
Transfer oil replacement ................................... MA-24
Transfer serial number ........................................ GI-48
Transmission serial number ................................ GI-48
Tread-FR&RR (Dimensions) ............................... GI-49
Trim ..................................................................... EI-34
TRNSCV - Wiring diagram ............................... BL-157
Trouble diagnoses .............................................. GI-11
Turbine revolution sensor ................................ AT-134
TURN - Wiring diagram ...................................... LT-83
Turn signal lamp ................................................. LT-80
Two trip detection logic ...................................... EC-49
Two-pole lift ........................................................ GI-41
V
Vacuum hose (brake system) ............................ BR-20
Vacuum hose drawing (Engine control) ............. EC-24
Valve clearance ................................................ EM-52
Valve guide ....................................................... EM-66
Vanity mirror lamp ............................................. LT-129
VDC (vehicle dynamics control) ........................ BRC-7
VDC -Wiring diagram ...................................... BRC-16
Vehicle identification number .............................. GI-47
Vehicle recovery (freeing a stuck vehicle) .......... GI-43
Vehicle speed sensor (VSS) ............................ EC-340
VEHSEC - Wiring diagram ................................. BL-80
VENT/V - Wiring diagram .................. EC-294, EC-506
Video Monitor ..................................................... AV-60
Viscosity number (SAE) .................................... MA-11
W
W/ANT - Wiring diagram .................................... AV-49
Wait detection switch ......................................... TF-96
WARN - Wiring diagram ..................................... DI-32
Warning chime .................................................... DI-43
Warning lamps .................................................... DI-31
Washer, front ..................................................... WW-4
Washer, rear .................................................... WW-33
Water pump ...................................................... CO-15
Water temperature gauge ..................................... DI-5
Wheel alignment (front) ..................................... FSU-6
Wheel alignment (rear) ................................... RSU-27
Wheel balance .................................................. MA-25
Wheel bearing (front) ......................................... FAX-5
Wheel bearing (rear) ......................................... RAX-5
Wheel hub (rear) ............................................... RAX-5
Wheel size .......................................................... GI-49
Wheelbase (Dimensions) .................................... GI-49
Width (Dimensions) ............................................. GI-49
WINDOW - Wiring diagram .............................. GW-22
Window, door ...................................... GW-69, GW-72
Windshield ....................................................... GW-11
WIP/R - Wiring diagram ................................... WW-37
WIPER - Wiring diagram .................................... WW-9
Wiper, front ........................................................ WW-4
Wiper, rear ....................................................... WW-33
Wiring Diagram (Cell code) list ......................... PG-61
Wiring diagram (Transfer) .................................. TF-18
Wiring diagrams .................................................. GI-15
WT-T/WARN - Wiring diagram .......................... WT-10

CAN COMMUNICATION
LAN-5
[CAN]
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LAN
Revision: August 20072004 QX56
CAN COMMUNICATIONPFP:23710
System DescriptionUKS000NU
CAN (Controller Area Network) is a serial communication line for real time application. It is an on-vehicle mul-
tiplex communication line with high data communication speed and excellent error detection ability. Many elec-
tronic control units are equipped onto a vehicle, and each control unit shares information and links with other
control units during operation (not independent). In CAN communication, control units are connected with 2
communication lines (CAN H line, CAN L line) allowing a high rate of information transmission with less wiring.
Each control unit transmits/receives data but selectively reads required data only.
CAN Communication UnitUKS000NV
Go to CAN system, when selecting your CAN system type from the following table.
×: Applicable
TYPE1
System diagram

Ty p e 1
Input/output signal chart
T: Transmit R: Receive Body typeWagon
Axle 2WD 4WD
EngineVK56DE
TransmissionA/T
Brake controlVDC
ICC system××
CAN system type 1234
CAN system trouble diagnosisLAN-16
LAN-50LAN-90LAN-126
PKIA8173E
Signals ECM TCMDriver
seat
con-
trol
unitCom-
bina-
tion
meterDis-
play
con-
trol
unitBCMStee r-
ing
angle
sensorFront
air
control ABS
actua-
tor and
elec-
tric unit
(con-
trol
unit)IPDM
E/R
Engine speed signal T R R R R
Engine status signal T R R