2005 INFINITI QX4 check engine

DTC P1754 INPUT CLUTCH SOLENOID VALVE FUNCTION
AT-143
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Revision: October 20052005 QX56
Diagnostic ProcedureECS00CHS
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 4.
NG >> GO TO 2.
2. CHECK TCM POWER SUPPLY AND GROUND CIRCUIT
Check TCM power supply and ground circuit. Refer to AT-168, "
MAIN POWER SUPPLY AND GROUND CIR-
CUIT" .
OK or NG
OK >> GO TO 3.
NG >> Repair or replace damaged parts.
3. 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 3 1 , "Control Valve With TCM and A/T Fluid
Temperature Sensor 2" .
NG >> Repair or replace damaged parts.
4. CHECK DTC
Perform “DTC Confirmation Procedure”.

Refer to AT- 1 4 2 , "DTC Confirmation Procedure" .
OK or NG
OK >>INSPECTION END
NG >> GO TO 2.
Item name Condition Display value
(Approx.)
I/C SOLE-
NOIDInput clutch disengaged. Refer to AT- 1 9
. 0.6 - 0.8 A
Input clutch engaged. Refer to AT- 1 9
. 0 - 0.05 A
ATF PRES
SW 3Input clutch engaged. Refer to AT- 1 9
.ON
Input clutch disengaged. Refer to AT- 1 9
.OFF
SCIA4795E

DTC P1757 FRONT BRAKE SOLENOID VALVE
AT-145
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Revision: October 20052005 QX56
Diagnostic ProcedureECS00CHY
1. CHECK INPUT SIGNAL
With CONSULT-II
1. Turn ignition switch “ON”.
2. Select “MAIN SIGNALS” in “DATA MONITOR” mode for “A/T”
with CONSULT-II.
3. Start engine.
4. Read out the value of “FR/B SOLENOID” while driving.
OK or NG
OK >> GO TO 4.
NG >> GO TO 2.
2. CHECK TCM POWER SUPPLY AND GROUND CIRCUIT
Check TCM power supply and ground circuit. Refer to AT-168, "
MAIN POWER SUPPLY AND GROUND CIR-
CUIT" .
OK or NG
OK >> GO TO 3.
NG >> Repair or replace damaged parts.
3. 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 3 1 , "Control Valve With TCM and A/T Fluid
Temperature Sensor 2" .
NG >> Repair or replace damaged parts.
4. CHECK DTC
Perform “DTC Confirmation Procedure”.

Refer to AT- 1 4 4 , "DTC Confirmation Procedure" .
OK or NG
OK >>INSPECTION END
NG >> GO TO 2.
Item name Condition Display value
(Approx.)
FR/B SOLE-
NOIDFront brake engaged. Refer to AT - 1 9
. 0.6 - 0.8 A
Front brake disengaged. Refer to AT- 1 9
. 0 - 0.05 ASCIA4793E

AT-146
DTC P1759 FRONT BRAKE SOLENOID VALVE FUNCTION
Revision: October 20052005 QX56
DTC P1759 FRONT BRAKE SOLENOID VALVE FUNCTIONPFP:31940
DescriptionECS00CHZ

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 ValueECS00CI0
On Board Diagnosis LogicECS00CI1

This is an OBD-II self-diagnostic item.

Diagnostic trouble code “P1759 FR/B SOLENOID FNCT” with CONSULT-II is detected under the follow-
ing 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 CauseECS00CI2

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

Front brake solenoid valve

ATF pressure switch 1
DTC Confirmation ProcedureECS00CI3
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-147, "
Diagnostic Procedure" .
If DTC (P1757) is detected, go to AT- 1 4 5 , "
Diagnostic Procedure" .
If DTC (P1841) is detected, go to AT- 1 6 1 , "
Diagnostic Procedure" .
Item name Condition Display value (Approx.)
FR/B SOLENOIDFront brake engaged. Refer to AT- 1 9
.0.6 - 0.8 A
Front brake disengaged. Refer to AT- 1 9
. 0 - 0.05 A
ATF PRES SW 1Front brake engaged. Refer to AT- 1 9
.ON
Front brake disengaged. Refer to AT- 1 9
.OFF
BCIA0030E

DTC P1759 FRONT BRAKE SOLENOID VALVE FUNCTION
AT-147
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Revision: October 20052005 QX56
Diagnostic ProcedureECS00CI4
1. CHECK INPUT SIGNALS
With CONSULT-II
1. Start engine.
2. Select “SELECTION FROM MENU” in “DATA MONITOR” mode
for “A/T” with CONSULT-II.
3. 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 4.
NG >> GO TO 2.
2. CHECK TCM POWER SUPPLY AND GROUND CIRCUIT
Check TCM power supply and ground circuit. Refer to AT-168, "
MAIN POWER SUPPLY AND GROUND CIR-
CUIT" .
OK or NG
OK >> GO TO 3.
NG >> Repair or replace damaged parts.
3. 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 3 1 , "Control Valve With TCM and A/T Fluid
Temperature Sensor 2" .
NG >> Repair or replace damaged parts.
4. CHECK DTC
Perform “DTC Confirmation Procedure”.

Refer to AT- 1 4 6 , "DTC Confirmation Procedure" .
OK or NG
OK >>INSPECTION END
NG >> GO TO 2.
Item name Condition Display value
(Approx.)
FR/B SOLE-
NOIDFront brake engaged. Refer to AT- 1 9
. 0.6 - 0.8 A
Front brake disengaged. Refer to AT- 1 9
. 0 - 0.05 A
ATF PRES
SW 1Front brake engaged. Refer to AT- 1 9
.ON
Front brake disengaged. Refer to AT- 1 9
.OFF
SCIA4796E

DTC P1762 DIRECT CLUTCH SOLENOID VALVE
AT-149
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Revision: October 20052005 QX56
Diagnostic ProcedureECS00CIA
1. CHECK INPUT SIGNAL
With CONSULT-II
1. Turn ignition switch “ON”.
2. Select “MAIN SIGNALS” in “DATA MONITOR” mode for “A/T”
with CONSULT-II.
3. Start the engine.
4. Read out the value of “D/C SOLENOID” while driving.
OK or NG
OK >> GO TO 4.
NG >> GO TO 2.
2. CHECK TCM POWER SUPPLY AND GROUND CIRCUIT
Check TCM power supply and ground circuit. Refer to AT-168, "
MAIN POWER SUPPLY AND GROUND CIR-
CUIT" .
OK or NG
OK >> GO TO 3.
NG >> Repair or replace damaged parts.
3. 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 3 1 , "Control Valve With TCM and A/T Fluid
Temperature Sensor 2" .
NG >> Repair or replace damaged parts.
4. CHECK DTC
Perform “DTC Confirmation Procedure”.

Refer to AT- 1 4 8 , "DTC Confirmation Procedure" .
OK or NG
OK >>INSPECTION END
NG >> GO TO 2.
Item name Condition Display value
(Approx.)
D/C SOLE-
NOIDDirect clutch disengaged. Refer to AT-1 9
. 0.6 - 0.8 A
Direct clutch engaged. Refer to AT- 1 9
. 0 - 0.05 ASCIA4793E

AT-150
DTC P1764 DIRECT CLUTCH SOLENOID VALVE FUNCTION
Revision: October 20052005 QX56
DTC P1764 DIRECT CLUTCH SOLENOID VALVE FUNCTIONPFP:31940
DescriptionECS00CIB

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 ValueECS00CIC
On Board Diagnosis LogicECS00CID

This is an OBD-II self-diagnostic item.

Diagnostic trouble code “P1764 D/C SOLENOID FNCTN” with CONSULT-II is detected under the follow-
ing 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 CauseECS00CIE

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

Direct clutch solenoid valve

ATF pressure switch 5
DTC Confirmation ProcedureECS00CIF
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-151, "
Diagnostic Procedure" .
If DTC (P1762) is detected, go to AT- 1 4 9 , "
Diagnostic Procedure" .
If DTC (P1845) is detected, go to AT- 1 6 5 , "
Diagnostic Procedure" .
WITH GST
Follow the procedure “With CONSULT-II”.
Item name Condition Display value (Approx.)
D/C SOLENOIDDirect clutch disengaged. Refer to AT-1 9
. 0.6 - 0.8 A
Direct clutch engaged. Refer to AT-1 9
. 0 - 0.05 A
ATF PRES SW 5Direct clutch engaged. Refer to AT-1 9
.ON
Direct clutch disengaged. Refer to AT-1 9
.OFF
BCIA0030E

DTC P1764 DIRECT CLUTCH SOLENOID VALVE FUNCTION
AT-151
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Revision: October 20052005 QX56
Diagnostic ProcedureECS00CIG
1. CHECK INPUT SIGNALS
With CONSULT-II
1. Start the engine.
2. Select “SELECTION FROM MENU” in “DATA MONITOR” mode
for “A/T” with CONSULT-II.
3. Drive vehicle in the “D” position (1st

2nd gear), and confirm
the display actuation of the “ATF PRES SW 5” and electrical cur-
rent value of “D/C SOLENOID”.
OK or NG
OK >> GO TO 4.
NG >> GO TO 2.
2. CHECK TCM POWER SUPPLY AND GROUND CIRCUIT
Check TCM power supply and ground circuit. Refer to AT-168, "
MAIN POWER SUPPLY AND GROUND CIR-
CUIT" .
OK or NG
OK >> GO TO 3.
NG >> Repair or replace damaged parts.
3. 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 3 1 , "Control Valve With TCM and A/T Fluid
Temperature Sensor 2" .
NG >> Repair or replace damaged parts.
4. CHECK DTC
Perform “DTC Confirmation Procedure”.

Refer to AT- 1 5 0 , "DTC Confirmation Procedure" .
OK or NG
OK >>INSPECTION END
NG >> GO TO 2.
Item name Condition Display value
(Approx.)
D/C SOLENOIDDirect clutch disengaged. Refer to AT- 1 9
. 0.6 - 0.8 A
Direct clutch engaged. Refer to AT- 1 9
. 0 - 0.05 A
ATF PRES SW 5Direct clutch engaged. Refer to AT- 1 9
.ON
Direct clutch disengaged. Refer to AT- 1 9
.OFF
SCIA4797E

DTC P1767 HIGH AND LOW REVERSE CLUTCH SOLENOID VALVE
AT-153
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Revision: October 20052005 QX56
Diagnostic ProcedureECS0 0CIM
1. CHECK INPUT SIGNAL
With CONSULT-II
1. Turn ignition switch “ON”.
2. Select “MAIN SIGNALS” in “DATA MONITOR” mode for “A/T”
with CONSULT-II.
3. Start the engine.
4. Read out the value of “HLR/C SOLENOID” while driving.
OK or NG
OK >> GO TO 4.
NG >> GO TO 2.
2. CHECK TCM POWER SUPPLY AND GROUND CIRCUIT
Check TCM power supply and ground circuit Refer to AT-168, "
MAIN POWER SUPPLY AND GROUND CIR-
CUIT" .
OK or NG
OK >> GO TO 3.
NG >> Repair or replace damaged parts.
3. 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 3 1 , "Control Valve With TCM and A/T Fluid
Temperature Sensor 2" .
NG >> Repair or replace damaged parts.
4. CHECK DTC
Perform “DTC Confirmation Procedure”.

Refer to AT- 1 5 2 , "DTC Confirmation Procedure" .
OK or NG
OK >>INSPECTION END
NG >> GO TO 2.
Item name Condition Display value
(Approx.)
HLR/C SOLHigh and low reverse clutch disengaged.
Refer to AT-1 9
.0.6 - 0.8 A
High and low reverse clutch engaged.
Refer to AT-1 9
.0 - 0.05 A
SCIA4793E