2004 INFINITI QX56 Can communication

TROUBLE DIAGNOSIS FOR SYMPTOMS
ACS-55
[ICC]
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ACS
Revision: August 20072004 QX56
Symptom 4: The ICC System Is Not Cancelled When the Gear Is in Other Than
‘D’
EKS007XV
1. CHECK D RANGE SWITCH
With CONSULT-II
1. With data monitor, check that “D RANGE SW” operates normally.
OK or NG
OK >> Replace ICC unit and erase DTC. Refer to ACS-59, "ICC Unit" . Perform ICC system running
test, and then perform self-diagnosis of ICC system again.
NG >> GO TO 2.
2. CHECK CAN COMMUNICATION
With CONSULT-II
1. With CONSULT-II self-diagnosis, check “CAN COMM CIRCUIT”.
OK or NG
OK >> GO TO 3.
NG >> Refer to ACS-38, "
DTC 20 CAN COMM CIRCUIT" .
3. CHECK D RANGE SWITCH
1. With TCM data monitor, check that “D” position switch operates normally.
OK or NG
OK >> Replace ICC unit. Refer to ACS-59, "ICC Unit" . Perform ICC system running test, and then per-
form self-diagnosis of ICC system again.
NG >> After repairing or replacing malfunctioning part. Perform ICC system running test, and then per-
form self-diagnosis of ICC system again.
Symptom 5: Chime Does Not SoundEKS007XW
The chime may not sound occasionally in the following cases even if the distance from the vehicle ahead is
short:

When the speed difference from that of the vehicle ahead is small (both vehicles driving at similar speed).

When the vehicle ahead drives at faster speed (the actual distance is increasing).

When depressing the accelerator.

Chime does not sound when the vehicle is not driving.

Chime does not sound when the system does not detect any vehicle ahead. (Diagnose the conditions
under which the system is detecting the vehicle ahead and when the system is malfunctioning. If there is
any malfunction in detecting the vehicle ahead, refer to ACS-56, "
Symptom 7: The ICC System Frequently
Cannot Detect the Vehicle Ahead/The Detection Zone is Short" .)
1. CHECK ICC WARNING CHIME
With CONSULT-II
1. With active test, check that ICC warning chime operates normally.
OK or NG
OK >> Determine preceding vehicle detection status when malfunction occurred. If chime should have
sounded replace ICC unit. Refer to ACS-59, "
ICC Unit" . Perform ICC system running test, and
then perform self-diagnosis of ICC system again.
NG >> GO TO 2.

ACS-56
[ICC]
TROUBLE DIAGNOSIS FOR SYMPTOMS
Revision: August 20072004 QX56
2. CAN COMMUNICATION INSPECTION
With CONSULT-II
1. With CONSULT-II self-diagnosis, check “CAN COMM CIRCUIT”.
OK or NG
OK >> Refer to ACS-38, "DTC 20 CAN COMM CIRCUIT" .
NG >> Replace combination meter and erase DTC. Refer to DI-25, "
Removal and Installation of Combi-
nation Meter" . Perform ICC system running test, and then perform self-diagnosis of ICC system
again.
Symptom 6: Driving Force Is HuntingEKS007XX
1. CHECK ECM
1. Perform self-diagnosis of ECM.
OK or NG
OK >> Refer to ACS-56, "Symptom 7: The ICC System Frequently Cannot Detect the Vehicle Ahead/The
Detection Zone is Short" .
NG >> After repairing applicable parts, erase DTC. Perform ICC system running test, and then perform
self-diagnosis of ICC system again.
Symptom 7: The ICC System Frequently Cannot Detect the Vehicle Ahead/The
Detection Zone is Short
EKS007XY
The detection function may become unstable in the following cases:

When the reflector of the vehicle ahead is small or not clean enough to reflect the laser.

When driving a road with extremely sharp corners.

When the laser cannot detect the reflector of the vehicle ahead as the vehicle ahead is passing a hill or
passing the peak.
1. VISUAL CHECK
1. Check ICC sensor body window for contamination and foreign materials.
OK or NG
OK >> If any contamination or foreign materials are found, remove them. Then perform ICC system run-
ning test.
NG >> GO TO 2.
2. CHECK FUNCTION
1. After performing laser beam aiming adjustment, perform ICC system running test. Check that preceding
vehicle detection performance has been improved.
OK or NG
OK >> Inspection End.
NG >>

Replace ICC sensor and perform laser beam aiming adjustment. Refer to ACS-59, "ICC Sen-
sor" .

After performing above, perform ICC system running test, and then perform self-diagnosis of
ICC system again.
Symptom 8: The System Does Not Detect the Vehicle Ahead at AllEKS007XZ
1. VISUAL CHECK
1. With ignition switch turned ON (engine not started), check that all indicator lamps in ICC system display
are continuously lit. (Check for a missing segment in preceding vehicle detection display.)
OK or NG
OK >> GO TO 2.
NG >> Check combination meter. Refer to DI-17, "
How to Proceed With Trouble Diagnosis" .

AT-1
AUTOMATIC TRANSMISSION
C TRANSMISSION/TRANSAXLE
CONTENTS
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SECTION AT
A
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AT
Revision: August 20072004 QX56 INDEX FOR DTC ........................................................ 5
Alphabetical Index .................................................... 5
DTC No. Index ......................................................... 6
PRECAUTIONS .......................................................... 7
Precautions for Supplemental Restraint System
(SRS) “AIR BAG” and “SEAT BELT PRE-TEN-
SIONER” .................................................................. 7
Precautions for On Board Diagnostic (OBD) System
of A/T and Engine .................................................... 7
Precautions .............................................................. 8
Service Notice or Precautions .................................. 9
Wiring Diagrams and Trouble Diagnosis .................. 9
PREPARATION ......................................................... 10
Special Service Tools ............................................. 10
Commercial Service Tools ...................................... 12
A/T FLUID ................................................................. 13
Changing A/T Fluid ................................................ 13
Checking A/T Fluid ................................................. 13
A/T Fluid Cooler Cleaning ...................................... 15
A/T CONTROL SYSTEM .......................................... 18
Cross-Sectional View (2WD models) ..................... 18
Cross-Sectional View (4WD models) ..................... 19
Shift Mechanism ..................................................... 20
TCM Function ......................................................... 31
CAN Communication .............................................. 32
Input/Output Signal of TCM .................................... 32
Line Pressure Control ............................................ 33
Shift Control ........................................................... 34
Lock-up Control ...................................................... 35
Engine Brake Control ............................................. 37
Control Valve .......................................................... 37
ON BOARD DIAGNOSTIC (OBD) SYSTEM ............ 39
Introduction ............................................................ 39
OBD-II Function for A/T System ............................. 39
One or Two Trip Detection Logic of OBD-II ............ 39
OBD-II Diagnostic Trouble Code (DTC) ................. 39
Malfunction Indicator Lamp (MIL) ........................... 42
TROUBLE DIAGNOSIS ............................................ 43
DTC Inspection Priority Chart ................................ 43
Fail-Safe ................................................................. 43How To Perform Trouble Diagnosis For Quick and
Accurate Repair ...................................................... 45
A/T Electrical Parts Location .................................. 50
Circuit Diagram ....................................................... 51
Wiring Diagram — AT — ........................................ 52
Inspections Before Trouble Diagnosis .................... 58
Check Before Engine is Started .............................. 62
Check at Idle ........................................................... 62
Cruise Test - Part 1 ................................................. 63
Cruise Test - Part 2 ................................................. 65
Cruise Test - Part 3 ................................................. 66
Vehicle Speed When Shifting Gears ...................... 67
Vehicle Speed When Performing and Releasing
Complete Lock-up .................................................. 67
Vehicle Speed When Performing and Releasing
Slip Lock-up ............................................................ 67
Symptom Chart ....................................................... 68
TCM Input/Output Signal Reference Values ........... 90
CONSULT-II Function (A/T) .................................... 91
DTC U1000 CAN COMMUNICATION LINE ............103
Description ............................................................103
On Board Diagnosis Logic ....................................103
Possible Cause .....................................................103
DTC Confirmation Procedure ...............................103
Diagnostic Procedure ...........................................104
DTC P0615 START SIGNAL CIRCUIT ...................105
Description ............................................................105
CONSULT-II Reference Value ..............................105
On Board Diagnosis Logic ....................................105
Possible Cause .....................................................105
DTC Confirmation Procedure ...............................105
Diagnostic Procedure ...........................................106
DTC P0700 TCM .....................................................108
Description ............................................................108
On Board Diagnosis Logic ....................................108
Possible Cause .....................................................108
DTC Confirmation Procedure ...............................108
Diagnostic Procedure ...........................................108
DTC P0705 PARK/NEUTRAL POSITION SWITCH .109
Description ............................................................109

AT-6
INDEX FOR DTC
Revision: August 20072004 QX56
DTC No. Index UCS002C0
NOTE:
If DTC U1000 is displayed with other DTC, first perform the trouble diagnosis for DTC U1000. Refer to
AT- 1 0 3 , "
DTC U1000 CAN COMMUNICATION LINE" .
*1: These numbers are prescribed by SAE J2012.
*2: These malfunctions cannot be displayed MIL if another malfunction is assigned to MIL.DTC
Items
(CONSULT- II screen terms)Reference page OBD- II Except OBD- II
CONSULT- II
GST (*1)C O N S U LT- I I
only “A/T”
— P0615 STARTER RELAY/CIRCAT- 1 0 5
P0700 P0700 TCMAT- 1 0 8
P0705 P0705 PNP SW/CIRCAT- 1 0 9
P0710 P1710 ATF TEMP SEN/CIRCAT- 1 3 1
P0720 P0720 VEH SPD SEN/CIR ATAT-11 2
— P0725 ENGINE SPEED SIGAT-11 5
P0740 P0740 TCC SOLENOID/CIRCAT-11 8
P0744 P0744 A/T TCC S/V FNCTNAT- 1 2 1
P0745 P0745 L/PRESS SOL/CIRCAT- 1 2 4
— P1702 TCM·RAMAT- 1 2 7
— P1703 TCM·ROMAT- 1 2 8
— P1705 TP SEN/CIRC A/TAT- 1 2 9
P1716 P1716 TURBINE REV S/CIRCAT- 1 3 6
— P1721 VEH SPD SE/CIR·MTRAT- 1 3 6
P1730 P1730 A/T INTERLOCKAT- 1 3 9
— P1731 A/T 1ST E/BRAKINGAT- 1 4 2
P1752 P1752 I/C SOLENOID/CIRCAT- 1 4 5
P1754 (*2 ) P1754 I/C SOLENOID FNCTNAT- 1 4 8
P1757 P1757 FR/B SOLENOID/CIRCAT- 1 5 1
P1759 (*2 ) P1759 FR/B SOLENOID FNCTAT- 1 5 4
P1762 P1762 D/C SOLENOID/CIRCAT- 1 5 7
P1764 (*2 ) P1764 D/C SOLENOID FNCTNAT- 1 6 0
P1767 P1767 HLR/C SOL/CIRCAT- 1 6 3
P1769 P1769 HLR/C SOL FNCTNAT- 1 6 6
P1772 P1772 LC/B SOLENOID/CIRCAT- 1 6 9
P1774 P1774 LC/B SOLENOID FNCTAT- 1 7 2
— P1841 ATF PRES SW 1/CIRCAT- 1 7 5
— P1843 ATF PRES SW 3/CIRCAT- 1 7 8
— P1845 ATF PRES SW 5/CIRCAT- 1 8 1
— P1846 ATF PRES SW 6/CIRCAT- 1 8 4
U1000 U1000 CAN COMM CIRCUITAT- 1 0 3

A/T CONTROL SYSTEM
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Revision: August 20072004 QX56
TCM FunctionUCS002CE
The function of the TCM is to:

Receive input signals sent from various switches and sensors.

Determine required line pressure, shifting point, lock-up operation, and engine brake operation.

Send required output signals to the respective solenoids.
CONTROL SYSTEM OUTLINE
The automatic transmission senses vehicle operating conditions through various sensors or signals. It always
controls the optimum shift position and reduces shifting and lock-up shocks.
CONTROL SYSTEM DIAGRAM
SENSORS (or SIGNALS)


TCM


ACTUATORS
PNP switch
Accelerator pedal position sensor
Closed throttle position signal
Wide open throttle position signal
Engine speed signal
A/T fluid temperature sensor
Revolution sensor
Vehicle speed signal
Stop lamp switch signal
Turbine revolution sensor
1st position switch signal
4th position switch signalShift control
Line pressure control
Lock-up control
Engine brake control
Timing control
Fail-safe control
Self-diagnosis
CONSULT-II communication line
Duet-EA control
CAN systemInput clutch solenoid valve
Direct clutch solenoid valve
Front brake solenoid valve
High and low reverse clutch
solenoid valve
Low coast brake solenoid valve
Torque converter clutch solenoid
valve
Line pressure solenoid valve
A/T CHECK indicator lamp
Sta rte r re lay
Back-up lamp relay
LCIA0317E

AT-32
A/T CONTROL SYSTEM
Revision: August 20072004 QX56
CAN CommunicationUCS002CF
SYSTEM DESCRIPTION
Refer to LAN-5, "CAN Communication Unit" .
Input/Output Signal of TCMUCS002CG
*1: Spare for vehicle speed sensor·A/T (revolution sensor)
*2: Spare for accelerator pedal position signal
*3: If these input and output signals are different, the TCM triggers the fail-safe function.
*4: CAN communicationsControl itemLine
pressure
controlVehicle
speed
controlShift
controlLock-up
controlEngine
brake
controlFail-safe
function
(*3)Self-diag-
nostics
function
InputAccelerator pedal position signal
(*4)XXXXXXX
Vehicle speed sensor A/T
(revolution sensor)XXXX XX
Vehicle speed sensor MTR
(*1) (*4)XXXX X
Closed throttle position signal
(*4)(*2) X (*2) X X (*2) X X
Wide open throttle position signal
(*4)(*2) X (*2) X (*2) X X
Turbine revolution sensor 1 X X X X X
Turbine revolution sensor 2
(for 4th speed only)XX X XX
Engine speed signals
(*4)XX
PNP switch XXXXXXX
A/T fluid temperature sensors 1, 2 X X X X X X X
ICC or
ASCDOperation signal
(*4)XXXX
Overdrive cancel
signal
(*4)XXX
TCM power supply voltage signal X X X X X X
Out-
putDirect clutch solenoid (ATF pres-
sure switch 5)XX XX
Input clutch solenoid (ATF pressure
switch 3)XX XX
High and low reverse clutch sole-
noid (ATF pressure switch 6)XX XX
Front brake solenoid (ATF pressure
switch 1)XX XX
Low coast brake solenoid (ATF
pressure switch 2)XX XXX
Line pressure solenoid X X X X X X X
TCC solenoid X X X
Starte r re la yXX

TROUBLE DIAGNOSIS
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Revision: August 20072004 QX56
TROUBLE DIAGNOSISPFP:00004
DTC Inspection Priority ChartUCS002C R
If some DTCs are displayed at the same time, perform inspections one by one based on the following priority
chart.
NOTE:
If DTC U1000 is displayed with other DTCs, first perform the trouble diagnosis for DTC U1000. Refer to
AT-1 03
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Fail-SafeUCS002CS
The TCM has an electrical fail-safe mode. This mode makes it possible to operate even if there is a an error in
a main electronic control input/output signal circuit. In fail-safe mode the transmission is fixed in 2nd or 4th
(depending on the breakdown position), so the customer should feel “slipping” or “poor acceleration”. When
fail-safe mode is triggered, when the ignition switch is switched “ON”, the AT CHECK indicator lamp flashes for
about 8 seconds.
Even when the electronic circuits are normal, under special conditions (for example, when slamming on the
brake with the wheels spinning drastically and stopping the tire rotation), the transmission can go into fail-safe
mode. If this happens, switch “OFF” the ignition switch for 10 seconds, then switch it “ON” again to return to
the normal shift pattern. Also, the AT CHECK indicator lamp flashes for about 8 seconds once, then is cleared.
Therefore, the customer's vehicle has returned to normal, so handle according to the “diagnostics flow” (Refer
to AT-46, "
WORK FLOW" ).
FAI L-S AFE FUN CT ION
If any malfunction occurs in a sensor or solenoid, this function controls the A/T to mark driving possible.
Vehicle Speed Sensor

Signals are input from two systems - from vehicle speed sensor A/T (revolution sensor) installed on the
transmission and from combination meter so normal driving is possible even if there is a malfunction in
one of the systems. And if vehicle speed sensor A/T (revolution sensor) has unusual cases, 5th gear is
prohibited.
Accelerator Pedal Position Sensor

If there is a malfunction in one of the systems, the accelerator opening angle is controlled by ECM accord-
ing to a pre-determined accelerator angle to make driving possible. And if there are malfunctions in tow
systems, the engine speed is fixed by ECM to a pre-determined engine speed to make driving possible.
Throttle Position Sensor

If there is a malfunction in one of the systems, the accelerator opening angle is controlled by ECM accord-
ing to a pre-determined accelerator angle to make driving possible. And if there are malfunctions in tow
systems, the accelerator opening angle is controlled by the idle signal sent from the ECM which is based
on input indicating either idle condition or off-idle condition (pre-determined accelerator opening) in order
to make driving possible.
PNP Switch

In the unlikely event that a malfunction signal enters the TCM, the position indicator is switched “OFF”, the
starter relay is switched “OFF” (starter starting is disabled), the back-up lamp relay switched “OFF” (back-
up lamp is OFF) and the position is fixed to the “D” range to make driving possible.
Starter Relay

The starter relay is switched “OFF”. (Starter starting is disabled.)
Priority Detected items (DTC)
1 U1000 CAN communication line
2 Except above

AT-48
TROUBLE DIAGNOSIS
Revision: August 20072004 QX56
4❏ Perform all road tests and enter checks in required inspection items.AT-6 1
4-1.Check before engine is started
AT-6 2
❏ AT-191, "AT CHECK Indicator Lamp Does Not Come On" .
❏ Perform self-diagnostics Enter checks for detected items. AT- 9 3
❏ AT- 1 0 3 , "DTC U1000 CAN COMMUNICATION LINE"
❏ AT- 1 0 5 , "DTC P0615 START SIGNAL CIRCUIT"
❏ AT- 1 0 8 , "DTC P0700 TCM"
❏ AT- 1 0 9 , "DTC P0705 PARK/NEUTRAL POSITION SWITCH"
❏ AT- 11 2 , "DTC P0720 VEHICLE SPEED SENSOR A/T (REVOLUTION SENSOR)"
❏ AT- 11 5 , "DTC P0725 ENGINE SPEED SIGNAL"
❏ AT- 11 8 , "DTC P0740 TORQUE CONVERTER CLUTCH SOLENOID VALVE"
❏ AT- 1 2 1 , "DTC P0744 A/T TCC S/V FUNCTION (LOCK-UP)"
❏ AT- 1 2 4 , "DTC P0745 LINE PRESSURE SOLENOID VALVE"
❏ AT- 1 2 7 , "DTC P1702 TRANSMISSION CONTROL MODULE (RAM)"
❏ AT- 1 2 8 , "DTC P1703 TRANSMISSION CONTROL MODULE (ROM)"
❏ AT- 1 2 9 , "DTC P1705 THROTTLE POSITION SENSOR"
❏ AT- 1 3 1 , "DTC P1710 A/T FLUID TEMPERATURE SENSOR CIRCUIT"
❏ AT- 1 3 4 , "DTC P1716 TURBINE REVOLUTION SENSOR"
❏ AT- 1 3 6 , "DTC P1721 VEHICLE SPEED SENSOR MTR"
❏ AT- 1 3 9 , "DTC P1730 A/T INTERLOCK"
❏ AT- 1 4 2 , "DTC P1731 A/T 1ST ENGINE BRAKING"
❏ AT- 1 4 5 , "DTC P1752 INPUT CLUTCH SOLENOID VALVE"
❏ AT- 1 4 8 , "DTC P1754 INPUT CLUTCH SOLENOID VALVE FUNCTION"
❏ AT- 1 5 1 , "DTC P1757 FRONT BRAKE SOLENOID VALVE"
❏ AT- 1 5 4 , "DTC P1759 FRONT BRAKE SOLENOID VALVE FUNCTION"
❏ AT- 1 5 7 , "DTC P1762 DIRECT CLUTCH SOLENOID VALVE"
❏ AT- 1 6 0 , "DTC P1764 DIRECT CLUTCH SOLENOID VALVE FUNCTION"
❏ AT- 1 6 3 , "DTC P1767 HIGH AND LOW REVERSE CLUTCH SOLENOID VALVE"
❏ AT- 1 6 6 , "DTC P1769 HIGH AND LOW REVERSE CLUTCH SOLENOID VALVE
FUNCTION"
❏ AT- 1 6 9 , "DTC P1772 LOW COAST BRAKE SOLENOID VALVE"
❏ AT- 1 7 2 , "DTC P1774 LOW COAST BRAKE SOLENOID VALVE FUNCTION"
❏ AT- 1 7 5 , "DTC P1841 ATF PRESSURE SWITCH 1"
❏ AT- 1 7 8 , "DTC P1843 ATF PRESSURE SWITCH 3"
❏ AT- 1 8 1 , "DTC P1845 ATF PRESSURE SWITCH 5"
❏ AT- 1 8 4 , "DTC P1846 ATF PRESSURE SWITCH 6"
4-2.Idle inspection
AT-6 2
❏ AT-192, "Engine Cannot Be Started In “P” or “N” Position"
❏ AT-193, "In “P” Position, Vehicle Moves When Pushed"
❏ AT-194, "In “N” Position, Vehicle Moves"
❏ AT-195, "Large Shock (“N” to “D” Position)"
❏ AT-198, "Vehicle Does Not Creep Backward In “R” Position"
❏ AT-201, "Vehicle Does Not Creep Forward In “D” Position"
4-3.Driving tests
AT-6 3
Part 1
❏ AT-203, "
Vehicle Cannot Be Started From D1"
❏ AT-206, "A/T Does Not Shift: D1 → D2"
❏ AT-208, "A/T Does Not Shift: D2 → D3"
❏ AT-210, "A/T Does Not Shift: D3 → D4"
❏ AT-213, "A/T Does Not Shift: D4 → D5"
❏ AT-215, "A/T Does Not Perform Lock-up"
❏ AT-217, "A/T Does Not Hold Lock-up Condition"
❏ AT-219, "Lock-up Is Not Released"
❏ AT-220, "Engine Speed Does Not Return to Idle"