Can communication INFINITI QX56 2004 Factory Workshop Manual

TROUBLE DIAGNOSIS
AT-93
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Revision: August 20072004 QX56
CONSULT-II SETTING PROCEDURE
CAUTION:
If CONSULT-II is used with no connection of CONSULT-II CONVERTER, malfunctions might be
detected in self-diagnosis depending on control unit which carries out CAN communication.

For details, refer to the separate “CONSULT-II Operations Man-
ual”.
1. Turn ignition switch “OFF”.
2. Connect CONSULT-II and CONSULT-II CONVERTER to data
link connector, which is located in instrument lower panel on
driver side.
3. Turn ignition switch “ON”. (Do not start engine.)
4. Touch “START (NISSAN BASED VHCL)”.
5. Touch “A/T”.
If “A/T” is not indicated, go to GI-39, "
CONSULT-II Data Link
Connector (DLC) Circuit" .
6. Perform each diagnostic test mode according to each service
procedure.
SELF-DIAGNOSTIC RESULT MODE
Operation Procedure
1. Perform “CONSULT-II SETTING PROCEDURE” Refer to AT-93, "CONSULT-II SETTING PROCEDURE"
.
2. Touch “SELF-DIAG RESULTS”.
Display shows malfunction experienced since the last erasing
operation.
BBIA0369E
BCIA0029E
BCIA0030E
BCIA0031E

AT-94
TROUBLE DIAGNOSIS
Revision: August 20072004 QX56
Display Items List
X: Applicable, —: Not applicable
Items (CONSULT-II
screen terms)Malfunction is detected when...TCM self-
diagnosisOBD-II (DTC)
“A/T” with
CONSULT-IIMIL indicator
lamp*1,
“ENGINE” with
CONSULT-II or
GST
CAN COMM CIRCUIT

When a malfunction is detected in CAN communications U1000 U1000
STARTER RELAY/
CIRC

If this signal is ON other than in P or N position, this is judged to be a
malfunction.
(And if it is OFF in P or N position, this too is judged to be a malfunc-
tion.)P0615 —
TCM

TCM is malfunctioning. P0700 P0700
PNP SW/CIRC

PNP switch 1-4 signals input with impossible pattern

PNP switch 3 monitor terminal cut line

“P” position is detected from N position without any other position
being detected in between.P0705 P0705
VEH SPD SEN/CIR AT
(Revolution sensor)

Signal from vehicle speed sensor A/T (Revolution sensor) not input
due to cut line or the like

Unexpected signal input during running

After ignition switch is turned ON, unexpected signal input from vehicle
speed sensor MTR before the vehicle starts movingP0720 P0720
ENGINE SPEED SIG

TCM does not receive the CAN communication signal from the ECM. P0725 —
TCC SOLENOID/CIRC

Normal voltage not applied to solenoid due to cut line, short, or the like P0740 P0740
A/T TCC S/V FNCTN

A/T cannot perform lock-up even if electrical circuit is good.

TCM detects as irregular by comparing difference value with slip rota-
tion.P0744 P0744*2
L/PRESS SOL/CIRC

Normal voltage not applied to solenoid due to cut line, short, or the like

TCM detects as irregular by comparing target value with monitor value.P0745 P0745
TCM·RAM

TCM memory (RAM) is malfunctioning. P1702 —
TCM·ROM

TCM memory (ROM) is malfunctioning. P1703 —
TP SEN/CIRC A/T

TCM does not receive the proper accelerator pedal position signals
(input by CAN communication) from ECM.P1705 P1705
ATF TEMP SEN/CIRC

During running, the ATF temperature sensor signal voltage is exces-
sively high or lowP1710 P0710
TURBINE REV S/CIRC

TCM does not receive the proper voltage signal from the sensor.

TCM detects an irregularity only at position of 4th gear for turbine revo-
lution sensor 2.P1716 P1716
VEH SPD SE/CIR·MTR

Signal (CAN communication) from vehicle speed sensor MTR not input
due to cut line or the like

Unexpected signal input during runningP1721 —
A/T INTERLOCK

Except during shift change, the gear position and ATF pressure switch
states are monitored and comparative judgement made.P1730 P1730
A/T 1ST E/BRAKING

Each ATF pressure switch and solenoid current is monitored and if a
pattern is detected having engine braking 1st gear other than in the M1
position, a malfunction is detected.P1731 —
I/C SOLENOID/CIRC

Normal voltage not applied to solenoid due to functional malfunction,
cut line, short, or the like

TCM detects as irregular by comparing target value with monitor value.P1752 P1752

TROUBLE DIAGNOSIS
AT-97
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DATA MONITOR MODE
Operation Procedure
1. Perform “CONSULT-II SETTING PROCEDURE” Refer to AT-93, "CONSULT-II SETTING PROCEDURE"
.
2. Touch “DATA MONITOR”.
NOTE:
When malfunction is detected, CONSULT-II performs
“REAL-TIME DIAGNOSIS”. Also, any malfunction detected
while in this mode will be displayed at real time.
Display Items List
X: Standard, —: Not applicable
BCIA0031E
Monitored item (Unit)Monitor Item Selection
Remarks ECU
INPUT
SIGNALSMAIN SIG-
NALSSELEC-
TION
FROM
MENU
VHCL/S SE·A/T (km/h) X X X Revolution sensor
VHCL/S SE·MTR (km/h) X — X
ACCELE POSI (0.0/8) X — X Accelerator pedal position signal
THROTTLE POSI (0.0/8) X X XDegree of opening for accelerator recognized by
the TCM
For fail-safe operation, the specific value used
for control is displayed.
CLSD THL POS (ON-OFF display) X — X
Signal input with CAN communications
W/O THL POS (ON-OFF display) X — X
BRAKE SW (ON-OFF display) X — X Stop lamp switch
GEAR — X XGear position recognized by the TCM updated
after gear-shifting
ENGINE SPEED (rpm) X X X
TURBINE REV (rpm) X X X
OUTPUT REV (rpm) X X X
GEAR RATIO — X X
TC SLIP SPEED (rpm) — X XDifference between engine speed and torque
converter input shaft speed
F SUN GR REV (rpm) — — X
F CARR GR REV (rpm) — — X
AT F T E M P S E 1 ( V ) X — X
AT F T E M P S E 2 ( V ) X — X
AT F T E M P 1 (°C) — X X
AT F T E M P 2 (°C) — X X
BATTERY VOLT (V) X — X
ATF PRES SW 1 (ON-OFF display) X X X (for FR/B solenoid)
ATF PRES SW 2 (ON-OFF display) X X X (for LC/B solenoid)
ATF PRES SW 3 (ON-OFF display) X X X (for I/C solenoid)

DTC U1000 CAN COMMUNICATION LINE
AT-103
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Revision: August 20072004 QX56
DTC U1000 CAN COMMUNICATION LINEPFP:23710
DescriptionUCS002D9
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 malfunction detection ability.
Many electronic 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 con-
nected 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.
On Board Diagnosis LogicUCS002DA

This is an OBD-II self-diagnostic item.

Diagnostic trouble code “CAN COMM CIRCUIT” with CONSULT-II or U1000 without CONSULT-II is
detected when TCM cannot communicate to other control units.
Possible CauseUCS002DB
Harness or connectors
(CAN communication line is open or shorted.)
DTC Confirmation ProcedureUCS002D C
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 “ENGINE” with CONSULT-II.
3. Start engine and wait for at least 6 seconds.
4. If DTC is detected, go to AT - 1 0 4 , "
Diagnostic Procedure" .
WITH GST
Follow the procedure “WITH CONSULT-II”.
BCIA0030E

AT-104
DTC U1000 CAN COMMUNICATION LINE
Revision: August 20072004 QX56
Diagnostic ProcedureUCS002DD
1. CHECK CAN COMMUNICATION CIRCUIT
With CONSULT-II
1. Turn ignition switch “ON” and start engine.
2. Select “SELF-DIAG RESULTS” mode for “A/T” with CONSULT-
II.
Is any malfunction of the
“CAN COMM CIRCUIT” indicated?
YES >> Print out CONSULT-II screen, GO TO LAN section.
Refer to LAN-3, "
Precautions When Using CONSULT-II"
.
NO >>INSPECTION END
PCIA0061E

DTC P0725 ENGINE SPEED SIGNAL
AT-115
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DTC P0725 ENGINE SPEED SIGNALPFP:24825
DescriptionUCS002E1
The engine speed signal is sent from the ECM to the TCM.
CONSULT-II Reference ValueUCS002E2
On Board Diagnosis LogicUCS002E3

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

Diagnostic trouble code “ENGINE SPEED SIG” with CONSULT-II is detected when TCM does not receive
the ignition signal from ECM during engine cranking or running.
Possible CauseUCS002E4
Harness or connectors
(The ECM to the TCM circuit is open or shorted.)
DTC Confirmation ProcedureUCS002E5
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 5 , "
Diagnostic Procedure" .
Diagnostic ProcedureUCS002E6
1. CHECK CAN COMMUNICATION LINE
Perform the self-diagnosis.Refer to AT- 9 3 , "
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.
Item name Condition Display value (rpm)
ENGINE SPEED Engine running Closely matches the tachometer reading.
BCIA0030E

DTC P1705 THROTTLE POSITION SENSOR
AT-129
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DTC P1705 THROTTLE POSITION SENSORPFP:22620
DescriptionUCS002EZ
Electric throttle control actuator consists of throttle control motor, accelerator pedal position sensor, throttle
position sensor, etc. The actuator sends a signal to the ECM, and ECM sends signals to TCM with CAN com-
munication.
CONSULT-II Reference ValueUCS002F0
On Board Diagnosis LogicUCS002F1

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

Diagnostic trouble code “TP SEN/CIRC A/T” with CONSULT-II is detected when TCM does not receive
the proper accelerator pedal position signals (input by CAN communication) from ECM.
Possible CauseUCS002F2
Harness or connectors
(The sensor circuit is open or shorted.)
DTC Confirmation ProcedureUCS002F3
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 let it idle for 1 second.
4. If DTC is detected, go to AT - 1 2 9 , "
Diagnostic Procedure" .
WITH GST
Follow the procedure “With CONSULT-II”.
Diagnostic ProcedureUCS002F4
1. CHECK CAN COMMUNICATION LINE
Perform the self-diagnosis. Refer to AT - 9 3 , "
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.
Item name Condition Display value (Approx.)
ACCELE 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
BCIA0030E

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-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
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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