2004 INFINITI FX35 brake sensor

DTC P1772 LOW COAST BRAKE SOLENOID VALVE
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Revision: 2004 November 2004 FX35/FX45
Diagnostic ProcedureACS007F4
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. Read out the value of “ON OFF SOL” while driving.
OK or NG
OK >> GO TO 4.
NG >> GO TO 2.
2. CHECK SELF-DIAGNOSTIC RESULTS
Perform self-diagnosis. Refer to AT- 9 4 , "
SELF-DIAGNOSTIC RESULT MODE" .
Do the self-diagnostic results indicate
“TCM-POWER SUPPLY”?
YES >> Check the TCM power circuit. Refer to AT- 1 2 9 , "DTC P1701 TRANSMISSION CONTROL MOD-
ULE (POWER SUPPLY)" .
NO >> GO TO 3.
3. 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 2 , "Control Valve with TCM and A/T Fluid Tem-
perature Sensor 2" .
NG >> Repair or replace damaged parts.
4. CHECK DTC
Perform “DTC Confirmation Procedure”.

Refer to AT- 1 6 8 , "DTC Confirmation Procedure" .
OK or NG
OK >>INSPECTION END
NG >> GO TO 2.
Item name Condition Display value
ON OFF
SOLLow coast brake engaged. Refer to AT- 2 0
.ON
Low coast brake disengaged. Refer to AT- 2 0
.OFF
SCIA4794E

AT-170
DTC P1774 LOW COAST BRAKE SOLENOID VALVE FUNCTION
Revision: 2004 November 2004 FX35/FX45
DTC P1774 LOW COAST BRAKE SOLENOID VALVE FUNCTIONPFP:31940
DescriptionACS007F5

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 ValueACS007F6
On Board Diagnosis LogicACS007F7

This is an OBD-II self-diagnostic item.

Diagnostic trouble code “LC/B SOLENOID FNCT” with CONSULT-II or P1774 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 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 CauseACS007F8

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

Low coast brake solenoid valve

ATF pressure switch 2
DTC Confirmation ProcedureACS007F9
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.
Selector lever: “M” position
Gear position: “M1-1st” or “M2-2nd” gear (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, refer to AT- 1 7 1 , "
Diagnostic Pro-
cedure" .
If DTC (P1772) is detected, go to AT- 1 6 9 , "
Diagnostic Proce-
dure" .
WITH GST
Follow the procedure “With CONSULT-II”.
Item name Condition Display value
ON OFF SOLLow coast brake engaged. Refer to AT- 2 0
.ON
Low coast brake disengaged. Refer to AT- 2 0
.OFF
ATF PRES SW 2Low coast brake engaged. Refer to AT- 2 0
.ON
Low coast brake disengaged. Refer to AT- 2 0
.OFF
SAT014K

DTC P1774 LOW COAST BRAKE SOLENOID VALVE FUNCTION
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Revision: 2004 November 2004 FX35/FX45
Diagnostic ProcedureACS007FA
1. CHECK INPUT SIGNALS
With CONSULT-II
1. Turn ignition switch “ON”. (Do not start engine.)
2. Select “SELECTION FORM MENU” in “DATA MONITOR” mode
for “A/T” with CONSULT-II.
3. Start the engine.
4. Drive vehicle in the manual mode (“M1-1st” or “M2-2nd” 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 SELF-DIAGNOSTIC RESULTS
Perform self-diagnosis. Refer to AT- 9 4 , "
SELF-DIAGNOSTIC RESULT MODE" .
Do the self-diagnostic results indicate
“TCM-POWER SUPPLY”?
YES >> Check the TCM power circuit. Refer to AT- 1 2 9 , "DTC P1701 TRANSMISSION CONTROL MOD-
ULE (POWER SUPPLY)" .
NO >> GO TO 3.
3. 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 2 , "Control Valve with TCM and A/T Fluid Tem-
perature Sensor 2" .
NG >> Repair or replace damaged parts.
4. CHECK DTC
Perform “DTC Confirmation Procedure”.

Refer to AT- 1 7 0 , "DTC Confirmation Procedure" .
OK or NG
OK >>INSPECTION END
NG >> GO TO 2.
Item name Condition Display value
ON OFF
SOLLow coast brake engaged. Refer to AT- 2 0
.ON
Low coast brake disengaged. Refer to AT- 2 0
.OFF
ATF PRES
SW 2Low coast brake engaged. Refer to AT- 2 0
.ON
Low coast brake disengaged. Refer to AT- 2 0
.OFF
SCIA4794E

DTC P1841 ATF PRESSURE SWITCH 1
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Revision: 2004 November 2004 FX35/FX45
Diagnostic ProcedureACS007FP
1. CHECK INPUT SIGNALS
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 SELF-DIAGNOSTIC RESULTS
Perform self-diagnosis. Refer to AT- 9 4 , "
SELF-DIAGNOSTIC RESULT MODE" .
Do the self-diagnostic results indicate
“TCM-POWER SUPPLY”?
YES >> Check the TCM power circuit. Refer to AT- 1 2 9 , "DTC P1701 TRANSMISSION CONTROL MOD-
ULE (POWER SUPPLY)" .
NO >> GO TO 3.
3. 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 2 , "Control Valve with TCM and A/T Fluid Tem-
perature Sensor 2" .
NG >> Repair or replace damaged parts.
4. CHECK DTC
Perform “DTC Confirmation Procedure”.

Refer to AT- 1 7 8 , "DTC Confirmation Procedure" .
OK or NG
OK >>INSPECTION END
NG >> GO TO 2.
Item name Condition Display value
ATF PRES SW 1Front brake engaged. Refer to AT- 2 0
.ON
Front brake disengaged. Refer to AT- 2 0
.OFF
PCIA0067E

TROUBLE DIAGNOSIS FOR SYMPTOMS
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Revision: 2004 November 2004 FX35/FX45
4. CHECK A/T FLUID CONDITION
1. Remove oil pan. Refer to AT- 2 4 2 , "
Control Valve with TCM and A/T Fluid Temperature Sensor 2" .
2. Check A/T fluid condition. Refer to AT- 5 1 , "
Fluid Condition
Check" .
OK or NG
OK >> GO TO 5.
NG >> Check the malfunction items. If any items are damaged,
repair or replace damaged parts. Refer to AT- 6 5 , "
Symp-
tom Chart" (Symptom No.67).
5. CHECK SYMPTOM
Check again. Refer to AT- 5 5 , "
Check at Idle" .
OK or NG
OK >>INSPECTION END
NG >> GO TO 6.
6. CHECK TCM
1. Check TCM input/output signals. Refer to AT- 9 0 , "
TCM Input/Output Signal Reference Values" .
2. If NG, recheck A/T assembly harness connector terminals for damage or loose connection with harness
connector.
OK or NG
OK >>INSPECTION END
NG >> Repair or replace damaged parts.
Large Shock (“N” to “D” Position)ACS007GH
SYMPTOM:
A noticeable shock occurs when the selector lever is shifted from the “N” to “D” position.
DIAGNOSTIC PROCEDURE
1. CHECK SELF-DIAGNOSTIC RESULTS
Perform self-diagnosis. Refer to AT- 9 4 , "
SELF-DIAGNOSTIC RESULT MODE" .
Do the self-diagnostic results indicate A/T fluid temperature sensor, engine speed signal, accelerator pedal
position sensor, ATF pressure switch 1, front brake solenoid valve, CAN communication line?
YES >> Check the malfunctioning system. Refer to AT- 1 3 9 , "DTC P1710 A/T FLUID TEMPERATURE
SENSOR CIRCUIT" , AT- 1 2 1 , "DTC P0725 ENGINE SPEED SIGNAL" , EC-555, "DTC P2122,
P2123 APP SENSOR" (for VQ35DE) or EC-1225, "DTC P2122, P2123 APP SENSOR" (for
VK45DE), EC-562, "
DTC P2127, P2128 APP SENSOR" (for VQ35DE) or EC-1232, "DTC P2127,
P2128 APP SENSOR" (for VK45DE), EC-576, "DTC P2138 APP SENSOR" (for VQ35DE) or
EC-1246, "
DTC P2138 APP SENSOR" (for VK45DE), AT- 1 3 6 , "DTC P1705 THROTTLE POSI-
TION SENSOR" , AT- 1 7 8 , "DTC P1841 ATF PRESSURE SWITCH 1" , AT- 1 5 6 , "DTC P1757
FRONT BRAKE SOLENOID VALVE" , AT- 1 0 5 , "DTC U1000 CAN COMMUNICATION LINE" .
NO >> GO TO 2.
2. ENGINE IDLE SPEED
Check the engine idle speed. Refer to EC-37, "
Idle Speed and Ignition Timing Check" (for VQ35DE) or EC-
685, "Idle Speed and Ignition Timing Check" (for VK45DE).
OK or NG
OK >> GO TO 3.
NG >> Repair.
SCIA5199E

TROUBLE DIAGNOSIS FOR SYMPTOMS
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Revision: 2004 November 2004 FX35/FX45
A/T Does Not Shift: D3 → D4ACS007GN
SYMPTOM:

The vehicle does not shift-up from the D3 to D4 gear at the specified speed.

The vehicle does not shift-up from the D3 to D4 gear unless A/T is warmed up.
DIAGNOSTIC PROCEDURE
1. CONFIRM THE SYMPTOM
Check if vehicle creeps forward in “D” position” and vehicle can be started from D
1.
OK or NG
OK >> GO TO 2.
NG >> Refer to AT- 2 0 1 , "
Vehicle Does Not Creep Forward In “D” Position" , AT- 2 0 3 , "Vehicle Cannot Be
Started From D1" .
2. CHECK SELF-DIAGNOSTIC RESULTS
Perform self-diagnosis. Refer to AT- 9 4 , "
SELF-DIAGNOSTIC RESULT MODE" .
Do the self-diagnostic results indicate ATF pressure switch 1, ATF pressure switch 3, front brake solenoid
valve, input clutch solenoid valve, accelerator pedal position sensor, vehicle speed sensor A/T (revolution sen-
sor) and vehicle speed sensor MTR?
YES >> Check the malfunctioning system. Refer to AT- 1 7 8 , "DTC P1841 ATF PRESSURE SWITCH 1" ,
AT- 1 8 0 , "
DTC P1843 ATF PRESSURE SWITCH 3" , AT- 1 5 2 , "DTC P1752 INPUT CLUTCH
SOLENOID VALVE" , AT- 1 5 6 , "DTC P1757 FRONT BRAKE SOLENOID VALVE" , EC-555, "DTC
P2122, P2123 APP SENSOR" (for VQ35DE) or EC-1225, "DTC P2122, P2123 APP SENSOR"
(for VK45DE), EC-562, "DTC P2127, P2128 APP SENSOR" (for VQ35DE) or EC-1232, "DTC
P2127, P2128 APP SENSOR" (for VK45DE), EC-576, "DTC P2138 APP SENSOR" (for
VQ35DE) or EC-1246, "
DTC P2138 APP SENSOR" (for VK45DE), AT- 1 3 6 , "DTC P1705
THROTTLE POSITION SENSOR" , AT- 11 6 , "DTC P0720 VEHICLE SPEED SENSOR A/T (REV-
OLUTION SENSOR)" , AT- 1 4 5 , "DTC P1721 VEHICLE SPEED SENSOR MTR" .
NO >> GO TO 3.
3. CHECK A/T FLUID LEVEL
Check A/T fluid level. Refer to AT- 1 2 , "
Checking A/T Fluid" .
OK or NG
OK >> GO TO 4.
NG >> Refill ATF.
4. CHECK LINE PRESSURE
Check line pressure at the engine stall point. Refer to AT- 5 2 , "
LINE
PRESSURE TEST" .
OK or NG
OK >> GO TO 7.
NG - 1 >> Line pressure high. GO TO 5.
NG - 2 >> Line pressure low. GO TO 6.
SAT638A
SAT494G

TROUBLE DIAGNOSIS FOR SYMPTOMS
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Revision: 2004 November 2004 FX35/FX45
10. CHECK TCM
1. Check TCM input/output signals. Refer to AT- 9 0 , "
TCM Input/Output Signal Reference Values" .
2. If NG, recheck A/T assembly harness connector terminals for damage or loose connection with harness
connector.
OK or NG
OK >>INSPECTION END
NG >> Repair or replace damaged parts.
11 . DETECT MALFUNCTIONING ITEM

Check the malfunction items. If any items are damaged, repair or replace damaged parts. Refer to AT- 6 5 ,
"Symptom Chart" (Symptom No.12).
OK or NG
OK >> GO TO 9.
NG >> Repair or replace damaged parts.
A/T Does Not Shift: D4 → D5ACS007GO
SYMPTOM:

The vehicle does not shift-up from the D4 to D5 gear at the specified speed.

The vehicle does not shift-up from the D4 to D5 gear unless A/T is warmed up.
DIAGNOSTIC PROCEDURE
1. CONFIRM THE SYMPTOM
Check if vehicle creeps forward in “D” position” and vehicle can be started from D
1.
OK or NG
OK >> GO TO 2.
NG >> Refer to AT- 2 0 1 , "
Vehicle Does Not Creep Forward In “D” Position" , AT- 2 0 3 , "Vehicle Cannot Be
Started From D1" .
2. CHECK SELF-DIAGNOSTIC RESULTS
Perform self-diagnosis. Refer to AT- 9 4 , "
SELF-DIAGNOSTIC RESULT MODE" .
Do the self-diagnostic results indicate ATF pressure switch 1, ATF pressure switch 5, front brake solenoid
valve, direct clutch solenoid valve, accelerator pedal position sensor, turbine revolution sensor, vehicle speed
sensor A/T (revolution sensor) and vehicle speed sensor MTR?
YES >> Check the malfunctioning system. Refer to AT- 1 7 8 , "DTC P1841 ATF PRESSURE SWITCH 1" ,
AT- 1 8 2 , "
DTC P1845 ATF PRESSURE SWITCH 5" , AT- 1 5 6 , "DTC P1757 FRONT BRAKE
SOLENOID VALVE" , AT- 1 6 0 , "DTC P1762 DIRECT CLUTCH SOLENOID VALVE" , EC-555,
"DTC P2122, P2123 APP SENSOR" (for VQ35DE) or EC-1225, "DTC P2122, P2123 APP SEN-
SOR" (for VK45DE), EC-562, "DTC P2127, P2128 APP SENSOR" (for VQ35DE) or EC-1232,
"DTC P2127, P2128 APP SENSOR" (for VK45DE), EC-576, "DTC P2138 APP SENSOR" (for
VQ35DE) or EC-1246, "
DTC P2138 APP SENSOR" (for VK45DE), AT- 1 3 6 , "DTC P1705
THROTTLE POSITION SENSOR" , AT- 1 4 3 , "DTC P1716 TURBINE REVOLUTION SENSOR" ,
AT- 11 6 , "
DTC P0720 VEHICLE SPEED SENSOR A/T (REVOLUTION SENSOR)" , AT- 1 4 5 , "DTC
P1721 VEHICLE SPEED SENSOR MTR" .
NO >> GO TO 3.

TROUBLE DIAGNOSIS FOR SYMPTOMS
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Revision: 2004 November 2004 FX35/FX45
Engine Speed Does Not Return To IdleACS007GS
SYMPTOM:
When a shift-down is performed, the engine speed does not smoothly return to the idling speed.
DIAGNOSTIC PROCEDURE
1. CHECK A/T FLUID LEVEL
Check A/T fluid level. Refer to AT- 1 2 , "
Checking A/T Fluid" .
OK or NG
OK >> GO TO 2.
NG >> Refill ATF.
2. CHECK SELF-DIAGNOSTIC RESULTS
Perform self-diagnosis. Refer to AT- 9 4 , "
SELF-DIAGNOSTIC RESULT MODE" .
Do the self-diagnostic results indicate front brake solenoid valve, direct clutch solenoid valve, ATF pressure
switch 1, ATF pressure switch 5, accelerator pedal position sensor, vehicle speed sensor A/T (revolution sen-
sor) and vehicle speed sensor MTR?
YES >> Check the malfunctioning system. Refer to AT- 1 5 6 , "DTC P1757 FRONT BRAKE SOLENOID
VA LV E" , AT- 1 6 0 , "DTC P1762 DIRECT CLUTCH SOLENOID VALVE" , AT- 1 7 8 , "DTC P1841 ATF
PRESSURE SWITCH 1" , AT- 1 8 2 , "DTC P1845 ATF PRESSURE SWITCH 5" , EC-555, "DTC
P2122, P2123 APP SENSOR" (for VQ35DE) or EC-1225, "DTC P2122, P2123 APP SENSOR"
(for VK45DE), EC-562, "DTC P2127, P2128 APP SENSOR" (for VQ35DE) or EC-1232, "DTC
P2127, P2128 APP SENSOR" (for VK45DE), EC-576, "DTC P2138 APP SENSOR" (for
VQ35DE) or EC-1246, "
DTC P2138 APP SENSOR" (for VK45DE), AT- 1 3 6 , "DTC P1705
THROTTLE POSITION SENSOR" , AT- 11 6 , "DTC P0720 VEHICLE SPEED SENSOR A/T (REV-
OLUTION SENSOR)" , AT- 1 4 5 , "DTC P1721 VEHICLE SPEED SENSOR MTR" .
NO >> GO TO 3.
3. CHECK A/T FLUID CONDITION
1. Remove oil pan. Refer to AT- 2 4 2 , "
Control Valve with TCM and A/T Fluid Temperature Sensor 2" .
2. Check A/T fluid condition. Refer to AT- 5 1 , "
Fluid Condition
Check" .
OK or NG
OK >> GO TO 4.
NG >> GO TO 7.
4. DETECT MALFUNCTIONING ITEM

Check the malfunction items. If any items are damaged, repair or replace damaged parts. Refer to AT- 6 5 ,
"Symptom Chart" (Symptom No.72).
OK or NG
OK >> GO TO 5.
NG >> Repair or replace damaged parts.
SAT638A
SCIA5199E