Infiniti M45 (Y34). Manual - part 76

DTC P1757 FRONT BRAKE SOLENOID VALVE

AT-189

D

E

F

G

H

I

J

K

L

M

A

B

AT

DTC P1757 FRONT BRAKE SOLENOID VALVE

PFP:31940

Description

ACS00493

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

ACS004PJ

On Board Diagnosis Logic

ACS00494

●

This is an OBD-II self-diagnostic item.

●

Diagnostic trouble code “FR/B SOLENOID/CIRC” with CONSULT-II or P1757 without 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

ACS00495

●

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

●

Front brake solenoid valve 

DTC Confirmation Procedure

ACS00496

CAUTION:

Always drive vehicle at a safe speed.
NOTE:
If “DTC Confirmation Procedure” has been previously conducted, always turn ignition switch OFF and
wait at least 10 seconds before conducting 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.

4.

Maintain the following conditions for at least 5 consecutive sec-
onds.
ACCELE POS: 1.5/8 - 2.0/8
Selector lever: “D” position 
Gear position: 3rd 

Þ

 4th Gear (FR/B ON/OFF)   

5.

If DTC is detected go to 

AT-191, "Diagnostic Procedure"

 .

 WITH GST

Follow the procedure “With CONSULT-II”.

Item name

Condition 

Display value (Approx.)

FR/B SOLENOID

Front brake solenoid valve operates. 

0.6 - 0.8 A

Other conditions

0 - 0.05 A

SAT014K

AT-190

DTC P1757 FRONT BRAKE SOLENOID VALVE

Wiring Diagram — AT — FR/B

ACS00497

TCWA0127E

DTC P1757 FRONT BRAKE SOLENOID VALVE

AT-191

D

E

F

G

H

I

J

K

L

M

A

B

AT

TCM terminal and data are reference value. Measured between each terminal and ground.

Diagnostic Procedure

ACS00498

1. 

CHECK INPUT SIGNALS

 With CONSULT-II

1.

Start engine.

2.

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

3.

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

 Without CONSULT-II

1.

Start engine.

2.

Check voltage between TCM connector and ground.

OK or NG

OK >> GO 

TO 

6.

NG

>> GO TO 2.

2. 

CHECK FRONT BRAKE SOLENOID VALVE CIRCUIT

1.

Turn ignition switch OFF.

2.

Disconnect A/T unit assembly harness connector at the trans-
mission right side.

3.

Check the resistance between terminal and ground.

OK or NG

OK >> GO 

TO 

5.

NG

>> GO TO 3.

Terminal   

No.

Wire 

color

Item

Condition

Data (Approx.)

19

R

Front brake sole-
noid valve

When 

vehicle 

starts

When the solenoid valve is operating (other than 4th gear)

More than 2.0V 

When the solenoid valve is not operating (4th gear)

0V

Item name

Condition 

Display value (Approx.)

FR/B SOLENOID

Front brake solenoid 
valve operates. 

0.6 - 0.8 A

Other conditions

0 - 0.05 A

SCIA4462E

Item

 Con-

nector 

No.

 Terminal 

No.

 Condition

Data 

(Approx.)

Front 

brake 

solenoid 

valve

 F103

 19 (R) - 

Ground

When 
vehicle 
cruises

When the solenoid 

valve is operating 

(other than 4th gear)

More than 

2.0V 

When the solenoid 

valve is not operating 

(4th gear)

0V

SCIA4574E

Solenoid valve

Connector No.

Terminal No. 

Resistance (Approx.)

Front brake solenoid 
valve

F27

5 - Ground

 3 - 9 

Ω

SCIA1839E

AT-192

DTC P1757 FRONT BRAKE SOLENOID VALVE

3. 

CHECK TERMINAL CORD ASSEMBLY

1.

Remove oil pan. Refer to 

AT-312, "Control Valve Assembly"

 .

2.

Disconnect A/T unit assembly harness connector and control valve assembly harness connector.

3.

Check continuity between A/T unit assembly harness connector
and control valve assembly harness connector.

4.

If OK, check harness for short to ground and short to power.

OK or NG

OK

>> GO TO 4.

NG

>> Repair open circuit or short to ground or short to power in harness or connectors.

4. 

CHECK VALVE RESISTANCE

Check valve resistance

●

Refer to 

AT-193, "Component Inspection"

 .

OK or NG

OK >> GO 

TO 

6.

NG

>> Replace the control valve assembly. Refer to 

AT-312, "Control Valve Assembly"

 .

5. 

CHECK POWER SOURCE CIRCUIT

1.

Turn ignition switch OFF.

2.

Disconnect TCM connector.

3.

Check continuity between A/T unit assembly harness connector
and TCM connector.

4.

If OK, check harness for short to ground and short to power.

5.

Reinstall any part removed.

OK or NG

OK

>> GO TO 6.

NG

>> Repair open circuit or short to ground or short to power in harness or connectors.

6. 

CHECK DTC

Perform “DTC Confirmation Procedure”. Refer to 

AT-189, "DTC Confirmation Procedure"

 .

OK or NG

OK

>> INSPECTION END

NG

>> GO TO 7.

Item

Connector No.

Terminal No. (Wire color)

Continuity

A/T unit assembly 
harness connector

F27

5 (W/R)

Yes

Control valve assem-
bly harness connec-
tor

F301

8 (W/R)

SCIA3076E

Item

Connector No.

Terminal No. 

(Wire color)

Continuity

TCM

F103

19 (R)

Yes

A/T unit assembly harness 
connector

F27

5 (R)

SCIA1840E