Infiniti Q45. Manual - part 58

DTC P1757 FRONT BRAKE SOLENOID VALVE

AT-145

DTC P1757 FRONT BRAKE SOLENOID VALVE

PFP:31940

Description

NCS000XW

Front brake 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.

CONSULT-II Reference Value

NCS000XX

On Board Diagnosis Logic

NCS000XY

●

This is an OBD-II self-diagnostic item.

●

Diagnostic trouble code “P1757 FR/B SOLENOID/CIRC” with CONSULT-II or 6th judgement flicker with-
out CONSULT-II is detected under the following conditions.

–

When TCM detects an improper voltage drop when it tries to operate the solenoid valve.

–

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

Possible Cause

NCS000XZ

●

Harness or connectors
(Solenoid circuit is open or shorted.)

●

Front brake solenoid valve

DTC Confirmation Procedure

NCS000Y0

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

Turn ignition switch ON. (Do not start engine.)

Select “SELECTION FROM MENU” in “DATA MONITOR” mode
for “A/T” with CONSULT-II and check monitor “ACCELE POSI”,
“SLCT LVR POSI” and “GEAR”.

Touch “START”.

Start engine.

Drive vehicle and maintain the following conditions for at least 5
consecutive seconds.
ACCELE POSI: 1.5/8 - 2.0/8
SLCT LVR POSI: “D” position
GEAR: “3”

“4” (FR/B ON/OFF)

Driving location: Driving the vehicle uphill (increased engine load) will help maintain the driving
conditions required for this test.

If DTC is detected go to

AT-146, "Diagnostic Procedure"

WITH GST

Follow the procedure “WITH CONSULT-II”.

Item name

Condition

Display value (Approx.)

FR/B SOLENOID

Front brake engaged. Refer to

AT-19

0.6 - 0.8 A

Front brake disengaged. Refer to

AT-19

0 - 0.05 A

BCIA0031E

AT-146

DTC P1757 FRONT BRAKE SOLENOID VALVE

Diagnostic Procedure

NCS000Y1

CHECK INPUT SIGNAL

With CONSULT-II

Turn ignition switch ON. (Do not start engine.)

Select “MAIN SIGNALS” in “DATA MONITOR” mode for “A/T”
with CONSULT-II.

Start engine.

Read out the value of “FR/B SOLENOID” while driving.

OK or NG

>> GO TO 4.

>> GO TO 2.

CHECK TCM POWER SUPPLY AND GROUND CIRCUIT

Check TCM power supply and ground circuit. Refer to

AT-173, "MAIN POWER SUPPLY AND GROUND CIR-

CUIT"

OK or NG

>> GO TO 3.

>> Repair or replace damaged parts.

DETECT MALFUNCTIONING ITEM

Check the following.

●

The A/T assembly harness connector pin terminals for damage or loose connection with harness connec-
tor.

OK or NG

>> Replace the control valve with TCM. Refer to

AT-225, "Control Valve with TCM and A/T Fluid Tem-

perature Sensor 2"

>> Repair or replace damaged parts.

CHECK DTC

Perform “DTC Confirmation Procedure”. Refer to

AT-145, "DTC Confirmation Procedure"

OK or NG

>> INSPECTION END

>> GO TO 2.

Item name

Condition

Display value
(Approx.)

FR/B SOLENOID

Front brake engaged. Refer to

AT-19

0.6 - 0.8 A

Front brake disengaged. Refer to

AT-19

0 - 0.05 A

SCIA4793E

DTC P1759 FRONT BRAKE SOLENOID VALVE FUNCTION

AT-147

DTC P1759 FRONT BRAKE SOLENOID VALVE FUNCTION

PFP:31940

Description

NCS000Y2

●

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 Value

NCS000Y3

On Board Diagnosis Logic

NCS000Y4

●

This is an OBD-II self-diagnostic item.

●

Diagnostic trouble code “P1759 FR/B SOLENOID FNCT” with CONSULT-II or 6th judgement flicker with-
out 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 Cause

NCS000Y5

●

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

●

Front brake solenoid valve

●

ATF pressure switch 1

DTC Confirmation Procedure

NCS000Y6

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

Start engine.

Accelerate vehicle to maintain the following conditions.
ACCELE POSI: 1.5/8 - 2.0/8
SLCT LVR POSI: “D” position
GEAR: “3”

“4” (FR/B ON/OFF)

Driving location: Driving the vehicle uphill (increased
engine load) will help maintain the driving conditions
required for this test.

Perform step “2” again.

Turn ignition switch OFF, then perform step “1” to “3” again.

Check “SELF-DIAG RESULTS” mode for “A/T” with CONSULT-
II.
If DTC (P1759) is detected, go to

AT-148, "Diagnostic Procedure"

If DTC (P1757) is detected, go to

AT-146, "Diagnostic Procedure"

If DTC (P1841) is detected, go to