2004 INFINITI QX56 Electric

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

DTC P0744 A/T TCC S/V FUNCTION (LOCK-UP)
AT-121
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Revision: August 20072004 QX56
DTC P0744 A/T TCC S/V FUNCTION (LOCK-UP)PFP:31940
DescriptionUCS002ED
This malfunction is detected when the A/T does not shift into 5th gear position or the torque converter clutch
does not lock-up as instructed by the TCM. This is not only caused by electrical malfunction (circuits open or
shorted) but also by mechanical malfunction such as control valve sticking, improper solenoid valve operation,
etc.
CONSULT-II Reference ValueUCS002EE
On Board Diagnosis LogicUCS002EF

This is an OBD-II self-diagnostic item.

Diagnostic trouble code “A/T TCC S/V FNCTN” with CONSULT-II or P0744 without CONSULT-II is
detected under the following conditions.
–When A/T cannot perform lock-up even if electrical circuit is good.
–When TCM detects as irregular by comparing difference value with slip rotation.
Possible CauseUCS002EG

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

Torque converter clutch solenoid valve

Hydraulic control circuit
DTC Confirmation ProcedureUCS002EH
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. Start engine and Select “TCC S/V FNCTN CHECK” of “DTC
WORK SUPPORT” mode for “A/T” with CONSULT-II and touch
“START”.
2. Accelerate vehicle to more than 80 km/h (50 MPH) and maintain
the following condition continuously until “TESTING” has turned
to “COMPLETE”. (It will take approximately 30 seconds after
“TESTING” shows.)
ACCELE POSI: More than 1.0/8 (at all times during step 4)
TCC SOLENOID: 0.4 - 0.6 A
Selector lever: “D” position
[Reference speed: Constant speed of more than 80 km/h (50
MPH)]
–Make sure “GEAR” shows “5”.
–For shift schedule, refer to AT- 6 7 , "Vehicle Speed When Performing and Releasing Complete Lock-
up" .
–If “TESTING” does not appear on CONSULT-II for a long time, select “SELF-DIAG RESULTS”. In
case a 1st trip DTC other than P0744 is shown, refer to applicable “TROUBLE DIAGNOSIS FOR
DTC”.
3. Make sure that “OK” is displayed. (If “NG” is displayed, refer to “DIAGNOSTIC PROCEDURE”.)
Refer to AT- 1 2 2 , "
Diagnostic Procedure" .
Refer to shift schedule, AT-67, "
Vehicle Speed When Performing and Releasing Complete Lock-up" .
Item name Condition Display value (Approx.) (A)
TCC SOLENOIDWhen performing slip lock-up 0.2 - 0.4
When performing lock-up 0.4 - 0.6
BCIA0030E

DTC P1705 THROTTLE POSITION SENSOR
AT-129
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Revision: August 20072004 QX56
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-148
DTC P1754 INPUT CLUTCH SOLENOID VALVE FUNCTION
Revision: August 20072004 QX56
DTC P1754 INPUT CLUTCH SOLENOID VALVE FUNCTIONPFP:31940
DescriptionUCS002G6

Input clutch solenoid valve is controlled by the TCM in response to signals sent from the PNP switch, vehi-
cle speed sensor and accelerator pedal position sensor (throttle position sensor). Gears will then be
shifted to the optimum position.

This is not only caused by electrical malfunction (circuits open or shorted) but also by mechanical mal-
function such as control valve sticking, improper solenoid valve operation.
CONSULT-II Reference ValueUCS002G7
On Board Diagnosis LogicUCS002G8

This is an OBD-II self-diagnostic item.

Diagnostic trouble code “I/C SOLENOID FNCTN” with CONSULT-II or P1754 without CONSULT-II is
detected under the following conditions.
–When TCM detects that actual gear ratio is irregular, and relation between gear position and condition of
pressure switch 3 is irregular during depressing accelerator pedal. (Other than during shift change)
–When TCM detects that relation between gear position and condition of ATF pressure switch 3 is irregular
during releasing accelerator pedal. (Other than during shift change)
Possible CauseUCS002G9

Harness or connectors
(The solenoid and switch circuits are open or shorted.)

Input clutch solenoid valve

ATF pressure switch 3
DTC Confirmation ProcedureUCS002GA
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. Start engine.
2. Accelerate vehicle to maintain the following conditions.
ACCELE POSI: 1.5/8 - 2.0/8
Selector lever: “D” position
Gear position: 3rd

4th Gear (I/C ON/OFF)
Driving location: Driving the vehicle uphill (increased
engine load) will help maintain the driving conditions
required for this test.
3. Perform step “2” again.
4. Turn ignition switch “OFF”, then perform step “1” to “3” again.
5. Check “SELF-DIAG RESULTS” mode for “A/T” with CONSULT-
II. If DTC (P1754) is detected, refer to AT-149, "
Diagnostic Procedure" .
If DTC (P1752) is detected, go to AT- 1 4 6 , "
Diagnostic Procedure" .
If DTC (P1843) is detected, go to AT- 1 7 9 , "
Diagnostic Procedure" .
Item name Condition Display value (Approx)
I/C SOLENOIDInput clutch disengaged. Refer to AT- 2 1
. 0.6 - 0.8 A
Input clutch engaged. Refer to AT- 2 1
. 0 - 0.05 A
ATF PRES SW 3Input clutch engaged. Refer to AT- 2 1
.ON
Input clutch disengaged. Refer to AT- 2 1
. OFF
BCIA0030E

DTC P1754 INPUT CLUTCH SOLENOID VALVE FUNCTION
AT-149
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Revision: August 20072004 QX56
WITH GST
Follow the procedure “With CONSULT-II”.
Diagnostic ProcedureUCS002G B
1. CHECK INPUT SIGNALS
With CONSULT-II
1. Turn ignition switch “ON”. (Do not start engine.)
2. Select “SELECTION FROM MENU” in “DATA MONITOR” mode
for “A/T” with CONSULT-II.
3. Start the engine.
4. Drive vehicle in the “D” position (3rd

4th gear), and confirm
the ON/OFF actuation of the “ATF PRES SW 3” and electrical
current value of “I/C SOLENOID”.
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 8 , "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.
Item name Condition Display value (Approx)
I/C SOLE-
NOIDInput clutch disengaged. Refer to AT- 2 1
. 0.6 - 0.8 A
Input clutch engaged. Refer to AT- 2 1
. 0 - 0.05 A
ATF PRES
SW 3Input clutch engaged. Refer to AT- 2 1
.ON
Input clutch disengaged. Refer to AT- 2 1
. OFF
SCIA4795E

AT-154
DTC P1759 FRONT BRAKE SOLENOID VALVE FUNCTION
Revision: August 20072004 QX56
DTC P1759 FRONT BRAKE SOLENOID VALVE FUNCTIONPFP:31940
DescriptionUCS002G I

Front brake solenoid valve is controlled by the TCM in response to signals sent from the PNP switch, vehi-
cle speed sensor and accelerator pedal position sensor (throttle position sensor). Gears will then be
shifted to the optimum position.

This is not only caused by electrical malfunction (circuits open or shorted) but also by mechanical mal-
function such as control valve sticking, improper solenoid valve operation.
CONSULT-II Reference ValueUCS002GJ
On Board Diagnosis LogicUCS002GK

This is an OBD-II self-diagnostic item.

Diagnostic trouble code “FR/B SOLENOID FNCT” with CONSULT-II or P1759 without CONSULT-II is
detected under the following conditions.
–When TCM detects that actual gear ratio is irregular, and relation between gear position and condition of
ATF pressure switch 1 is irregular during depressing accelerator pedal. (Other than during shift change)
–When TCM detects that relation between gear position and condition of ATF pressure switch 1 is irregular
during releasing accelerator pedal. (Other than during shift change)
Possible CauseUCS002GL

Harness or connectors
(The solenoid and switch circuits are open or shorted.)

Front brake solenoid valve

ATF pressure switch 1
DTC Confirmation ProcedureUCS002GM
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. Start engine.
2. Accelerate vehicle to maintain the following conditions.
ACCELE POS: 1.5/8 - 2.0/8
Selector lever: “D” position
Gear position: 3rd

4th Gear (FR/B ON/OFF)
Driving location: Driving the vehicle uphill (increased
engine load) will help maintain the driving conditions
required for this test.
3. Perform step “2” again.
4. Turn ignition switch “OFF”, then perform step “1” to “3” again.
5. Check “SELF-DIAG RESULTS” mode for “A/T” with CONSULT-
II. If DTC (P1759) is detected, refer to AT-155, "
Diagnostic Procedure" .
If DTC (P1757) is detected, go to AT- 1 5 2 , "
Diagnostic Procedure" .
If DTC (P1841) is detected, go to AT- 1 7 6 , "
Diagnostic Procedure" .
Item name Condition Display value (Approx)
FR/B SOLENOIDFront brake engaged. Refer to AT- 2 1
. 0.6 - 0.8 A
Front brake disengaged. Refer to AT- 2 1
. 0 - 0.05 A
ATF PRES SW 1Front brake engaged. Refer to AT- 2 1
.ON
Front brake disengaged. Refer to AT- 2 1
. OFF
BCIA0030E

DTC P1759 FRONT BRAKE SOLENOID VALVE FUNCTION
AT-155
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Revision: August 20072004 QX56
WITH GST
Follow the procedure “With CONSULT-II”.
Diagnostic ProcedureUCS002G N
1. CHECK INPUT SIGNALS
With CONSULT-II
1. Turn ignition switch “ON”. (Do not start engine.)
2. Select “SELECTION FROM MENU” in “DATA MONITOR” mode
for “A/T” with CONSULT-II.
3. Start the engine.
4. Drive vehicle in the “D” position (3rd

4th gear), and confirm
the ON/OFF actuation of the “ATF PRES SW 1” and electrical
current value of “FR/B SOLENOID”.
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 5 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.
Item name Condition Display value (Approx)
FR/B SOLE-
NOIDFront brake engaged. Refer to AT- 2 1
. 0.6 - 0.8 A
Front brake disengaged. Refer to AT- 2 1
. 0 - 0.05 A
ATF PRES
SW 1Front brake engaged. Refer to AT- 2 1
. ON
Front brake disengaged. Refer to AT- 2 1
. OFF
SCIA4796E

AT-160
DTC P1764 DIRECT CLUTCH SOLENOID VALVE FUNCTION
Revision: August 20072004 QX56
DTC P1764 DIRECT CLUTCH SOLENOID VALVE FUNCTIONPFP:31940
DescriptionUCS002GU

Direct clutch solenoid valve is controlled by the TCM in response to signals sent from the PNP switch,
vehicle speed sensor and accelerator pedal position sensor (throttle position sensor). Gears will then be
shifted to the optimum position.

This is not only caused by electrical malfunction (circuits open or shorted) but also by mechanical mal-
function such as control valve sticking, improper solenoid valve operation.
CONSULT-II Reference ValueUCS002GV
On Board Diagnosis LogicUCS002GW

This is an OBD-II self-diagnostic item.

Diagnostic trouble code “D/C SOLENOID FNCTN” with CONSULT-II or P1764 without CONSULT-II is
detected under the following conditions.
–When TCM detects that actual gear ratio is irregular, and relation between gear position and condition of
ATF pressure switch 5 is irregular during depressing accelerator pedal. (Other than during shift change)
–When TCM detects that relation between gear position and condition of ATF pressure switch 5 is irregular
during releasing accelerator pedal. (Other than during shift change)
Possible CauseUCS002GX

Harness or connectors
(The solenoid and switch circuits are open or shorted.)

Direct clutch solenoid valve

ATF pressure switch 5
DTC Confirmation ProcedureUCS002GY
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. Start engine.
2. Accelerate vehicle to maintain the following conditions.
ACCELE POS: 1.5/8 - 2.0/8
Selector lever: “D” position
Gear position: 1st

2nd Gear (D/C ON/OFF)
Driving location: Driving the vehicle uphill (increased
engine load) will help maintain the driving conditions
required for this test.
3. Perform step “2” again.
4. Turn ignition switch “OFF”, then perform step “1” to “3” again.
5. Check “SELF-DIAG RESULTS” mode for “A/T” with CONSULT-
II. If DTC (P1764) is detected, refer to AT-161, "
Diagnostic Procedure" .
If DTC (P1762) is detected, go to AT- 1 5 8 , "
Diagnostic Procedure" .
If DTC (P1845) is detected, go to AT- 1 8 2 , "
Diagnostic Procedure" .
WITH GST
Follow the procedure “With CONSULT-II”.
Item name Condition Display value (Approx)
D/C SOLENOIDDirect clutch disengaged. Refer to AT-2 1
. 0.6 - 0.8 A
Direct clutch engaged. Refer to AT-2 1
. 0 - 0.05 A
ATF PRES SW 5Direct clutch engaged. Refer to AT-2 1
.ON
Direct clutch disengaged. Refer to AT-2 1
.OFF
BCIA0030E