2007 INFINITI FX35 brake

AT-162
DTC P1772 LOW COAST BRAKE SOLENOID VALVE
Revision: 2006 July 2007 FX35/FX45
DTC P1772 LOW COAST BRAKE SOLENOID VALVEPFP:31940
DescriptionNCS001G1
Low coast brake solenoid valve is turned ON or OFF 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 ValueNCS001G2
On Board Diagnosis LogicNCS001G3

This is an OBD-II self-diagnostic item.

Diagnostic trouble code “P1772 LC/B SOLENOID/CIRC” with CONSULT-II or 7th judgement flicker with-
out CONSULT-II is detected when TCM detects an improper voltage drop when it tries to operate the sole-
noid valve.
Possible CauseNCS001G4

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

Low coast brake solenoid valve
DTC Confirmation ProcedureNCS001G5
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.
2. Select “SELECTION FROM MENU” in “DATA MONITOR” mode for “A/T” with CONSULT-II and check monitor “MANU MODE
SW” and “GEAR”.
3. Touch “START”.
4. Start engine.
5. Drive vehicle and maintain the following conditions for at least 5 consecutive seconds.
MANU MODE SW: ON
GEAR: “1” or “2” (LC/B ON/OFF)
6. If DTC is detected, go to AT- 1 6 3 , "
Diagnostic Procedure" .
WITH GST
Follow the procedure “WITH CONSULT-II”.
Item name Condition Display value
ON OFF SOL Low coast brake engaged. Refer to
AT- 2 2
.ON
Low coast brake disengaged. Refer to AT- 2 2
.OFF
BCIA0031E

DTC P1772 LOW COAST BRAKE SOLENOID VALVE AT-163
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Revision: 2006 July 2007 FX35/FX45
Diagnostic ProcedureNCS001G6
1. CHECK INPUT SIGNAL
With CONSULT-II
1. Turn ignition switch ON.
2. Select “SELECTION FROM MENU” in “DATA MONITOR” mode for “A/T” with CONSULT-II.
3. Start engine.
4. Read out the value of “ON OFF SOL” 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- 1 7 9 , "
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 A/T assembly harness connector pin terminals for damage or loose connection with harness connector.
OK or NG
OK >> Replace the control valve with TCM. Refer to AT- 2 3 9 , "Control Valve with TCM and A/T Fluid Tem-
perature Sensor 2" .
NG >> Repair or replace damaged parts.
4. CHECK DTC
Perform AT- 1 6 2 , "
DTC Confirmation Procedure" .
OK or NG
OK >> INSPECTION END
NG >> GO TO 2.
Item name Condition Display value
ON OFF SOL Low coast brake engaged. Refer to
AT- 2 2
.ON
Low coast brake disengaged. Refer to AT- 2 2
.OFF
SCIA4794E

AT-164
DTC P1774 LOW COAST BRAKE SOLENOID VALVE FUNCTION
Revision: 2006 July 2007 FX35/FX45
DTC P1774 LOW COAST BRAKE SOLENOID VALVE FUNCTIONPFP:31940
DescriptionNCS001G7

Low coast brake solenoid valve is turned ON or OFF 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 ValueNCS001G8
On Board Diagnosis LogicNCS001G9

This is an OBD-II self-diagnostic item.

Diagnostic trouble code “P1774 LC/B SOLENOID FNCT” with CONSULT-II or 7th 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 2 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 2 is irregular
during releasing accelerator pedal. (Other than during shift change)
Possible CauseNCS001GA

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

Low coast brake solenoid valve

ATF pressure switch 2
DTC Confirmation ProcedureNCS001GB
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. MANU MODE SW: ON
GEAR: “1” or “2” (LC/B ON/OFF)
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 (P1774) is detected, go to AT- 1 6 5 , "
Diagnostic Proce-
dure" .
If DTC (P1772) is detected, go to AT- 1 6 3 , "
Diagnostic Proce-
dure" .
WITH GST
Follow the procedure “WITH CONSULT-II”.
Item name Condition Display value
ON OFF SOL Low coast brake engaged. Refer to
AT- 2 2
.ON
Low coast brake disengaged. Refer to AT- 2 2
.OFF
ATF PRES SW 2 Low coast brake engaged. Refer to
AT- 2 2
.ON
Low coast brake disengaged. Refer to AT- 2 2
.OFF
BCIA0031E

DTC P1774 LOW COAST BRAKE SOLENOID VALVE FUNCTION AT-165
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Revision: 2006 July 2007 FX35/FX45
Diagnostic ProcedureNCS001GC
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 manual mode (1st or 2nd gear), and confirm the ON/OFF actuation of the “ATF PRES SW 2” and “ON OFF
SOL”.
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- 1 7 9 , "
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 A/T assembly harness connector pin terminals for damage or loose connection with harness connector.
OK or NG
OK >> Replace the control valve with TCM. Refer to AT- 2 3 9 , "Control Valve with TCM and A/T Fluid Tem-
perature Sensor 2" .
NG >> Repair or replace damaged parts.
4. CHECK DTC
Perform AT- 1 6 4 , "
DTC Confirmation Procedure" .
OK or NG
OK >> INSPECTION END
NG >> GO TO 2.
Item name Condition Display value
ON OFF SOL Low coast brake engaged. Refer to
AT- 2 2
.ON
Low coast brake disengaged. Refer to AT- 2 2
.OFF
ATF PRES SW 2 Low coast brake engaged. Refer to
AT- 2 2
.ON
Low coast brake disengaged. Refer to AT- 2 2
.OFF
SCIA4794E

DTC P1841 ATF PRESSURE SWITCH 1 AT-171
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Revision: 2006 July 2007 FX35/FX45
DTC P1841 ATF PRESSURE SWITCH 1PFP:25240
DescriptionNCS001GL
Fail-safe function to detect front brake solenoid valve condition.
CONSULT-II Reference ValueNCS001GM
On Board Diagnosis LogicNCS001GN

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

Diagnostic trouble code “P1841 ATF PRES SW 1/CIRC” with CONSULT-II is detected when TCM detects
that actual gear ratio is normal, and relation between gear position and condition of ATF pressure switch 1
is irregular during depressing accelerator pedal. (Other than during shift change)
Possible CauseNCS001GO

ATF pressure switch 1

Harness or connectors
(Switch circuit is open or shorted.)
DTC Confirmation ProcedureNCS001GP
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
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.
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 (P1841) is detected, go to AT- 1 7 2 , "
Diagnostic Procedure" .
If DTC (P1757) is detected, go to AT- 1 5 1 , "
Diagnostic Procedure" .
Item name Condition Display value
ATF PRES SW 1 Front brake engaged. Refer to
AT- 2 2
.ON
Front brake disengaged. Refer to AT- 2 2
.OFF
BCIA0031E

AT-172
DTC P1841 ATF PRESSURE SWITCH 1
Revision: 2006 July 2007 FX35/FX45
Diagnostic ProcedureNCS001GQ
1. CHECK INPUT SIGNAL
With CONSULT-II
1. Start engine.
2. Select “ECU INPUT SIGNALS” or “MAIN SIGNALS” 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”.
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- 1 7 9 , "
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 A/T assembly harness connector pin terminals for damage or loose connection with harness connector.
OK or NG
OK >> Replace the control valve with TCM. Refer to AT- 2 3 9 , "Control Valve with TCM and A/T Fluid Tem-
perature Sensor 2" .
NG >> Repair or replace damaged parts.
4. CHECK DTC
Perform AT- 1 7 1 , "
DTC Confirmation Procedure" .
OK or NG
OK >> INSPECTION END
NG >> GO TO 2.
Item name Condition Display value
ATF PRES SW 1 Front brake engaged. Refer to
AT- 2 2
.ON
Front brake disengaged. Refer to AT- 2 2
.OFF
PCIA0067E

AT-184
BRAKE SIGNAL CIRCUIT
Revision: 2006 July 2007 FX35/FX45
BRAKE SIGNAL CIRCUITPFP:25320
CONSULT-II Reference ValueNCS001HD
Diagnostic ProcedureNCS001HE
1. CHECK CAN COMMUNICATION LINE
Perform the self-diagnosis. Refer to AT- 9 2 , "
SELF-DIAGNOSTIC RESULT MODE" , AT- 1 0 2 , "Diagnostic Pro-
cedure without CONSULT-II" .
Is a malfunction in the CAN communication indicated in the results?
YES >> Check CAN communication line. Refer to AT- 1 0 4 , "DTC U1000 CAN COMMUNICATION LINE" .
NO >> GO TO 2.
2. CHECK STOP LAMP SWITCH CIRCUIT
With CONSULT-II
1. Turn ignition switch ON.
2. Select “ECU INPUT SIGNALS” in “DATA MONITOR” mode for “A/T” with CONSULT-II.
3. Read out ON/OFF switching action of the “BRAKE SW”.
OK or NG
OK >> INSPECTION END
NG >> GO TO 3.
3. CHECK STOP LAMP SWITCH
Check continuity between stop lamp switch harness connector E210
terminals 1 and 2. Refer to AT- 1 8 6 , "
Wiring Diagram — AT — NON-
DTC" .
Check stop lamp switch after adjusting brake pedal — refer to
BR-6, "
BRAKE PEDAL" .
OK or NG
OK >> Check the following items. If NG, repair or replace dam- aged parts.

Harness for short or open between battery and stop lamp switch.

Harness for short or open between stop lamp switch and unified meter and A/C amp.
NG >> Repair or replace the stop lamp switch.
Item name Condition Display value
BRAKE SW Depressed brake pedal. ON
Released brake pedal. OFF
Item name Condition Display value
BRAKE SW Depressed brake pedal. ON
Released brake pedal. OFF
PCIA0070E
Condition Continuity
When brake pedal is depressed Yes When brake pedal is released No
SCIA2144E

TROUBLE DIAGNOSIS FOR SYMPTOMS AT-197
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Revision: 2006 July 2007 FX35/FX45
5. DETECT MALFUNCTIONING ITEM
1. Disassemble A/T. Refer to AT- 2 9 4 , "
DISASSEMBLY" .
2. Check the following.
–Reverse brake. Refer to AT- 2 9 4 , "DISASSEMBLY" .
OK or NG
OK >> GO TO 9.
NG >> Repair or replace damaged parts.
6. CHECK LINE PRESSURE
Check the line pressure with the engine idling. Refer to AT- 5 4 , "
LINE
PRESSURE TEST" .
OK or NG
OK >> GO TO 9.
NG-1 >> Line pressure high: GO TO 7.
NG-2 >> Line pressure low: GO TO 8.
7. DETECT MALFUNCTIONING ITEM
1. Check control valve with TCM. Refer to AT- 2 3 9 , "
Control Valve with TCM and A/T Fluid Temperature Sen-
sor 2" .
2. Disassemble A/T. Refer to AT- 2 9 4 , "
DISASSEMBLY" .
3. Check the following.
–Oil pump assembly. Refer to AT- 3 1 2 , "Oil Pump" .
OK or NG
OK >> GO TO 9.
NG >> Repair or replace damaged parts.
8. DETECT MALFUNCTIONING ITEM
1. Check control valve with TCM. Refer to AT- 2 3 9 , "
Control Valve with TCM and A/T Fluid Temperature Sen-
sor 2" .
2. Disassemble A/T. Refer to AT- 2 9 4 , "
DISASSEMBLY" .
3. Check the following.
–Oil pump assembly. Refer to AT- 3 1 2 , "Oil Pump" .
–Power train system. Refer to AT- 2 9 4 , "DISASSEMBLY" .
–Transmission case. Refer to AT- 2 9 4 , "DISASSEMBLY" .
OK or NG
OK >> GO TO 9.
NG >> Repair or replace damaged parts.
SAT494G