2004 INFINITI FX35 Engine

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
AT-171
D
E
F
G
H
I
J
K
L
MA
B
AT
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

AT-172
DTC P1815 MANUAL MODE SWITCH
Revision: 2004 November 2004 FX35/FX45
DTC P1815 MANUAL MODE SWITCHPFP:34901
DescriptionACS007FB
Manual mode switch is installed in A/T device. It sends manual mode switch, shift up and shift down switch
signals to TCM.
TCM sends the switch signals to unified meter and A/C amp. With CAN communication line. Then manual
mode switch position is indicated on the A/T position indicator. For inspection, refer to AT- 1 7 7 , "
A/T Position
Indicator" .
CONSULT-II Reference Value in Data Monitor ModeACS007FC
On Board Diagnosis LogicACS007FD

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

Diagnostic trouble code “MANU MODE SW/CIR” with CONSULT-II is detected when TCM monitors Man-
ual mode, Non manual mode, Up or Down switch signal, and detects as irregular when impossible input
pattern occurs 1 second or more.
Possible CauseACS007FE

Harness or connectors
(These switches circuit is open or shorted.)

Mode select switch (Into control device)

Position select switch (Into control device)
DTC Confirmation ProcedureACS007FF
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”. (Do not start engine.)
2. Select “DATA MONITOR” mode for “A/T” with CONSULT-II.
3. Start engine.
4. Move selector lever to “M” position.
5. Drive vehicle for at least 2 consecutive seconds.
6. If DTC is detected, go to AT- 1 7 5 , "
Diagnostic Procedure" .
Item name Condition Display value
MANU MODE SWManual shift gate position (neutral) ON
Other than the above OFF
NON M-MODE SWManual shift gate position OFF
Other than the above ON
UP SW LEVERSelector lever: + side ON
Other than the above OFF
DOWN SW LEVERSelector lever: - side ON
Other than the above OFF
SAT014K

DTC P1815 MANUAL MODE SWITCH
AT-175
D
E
F
G
H
I
J
K
L
MA
B
AT
Revision: 2004 November 2004 FX35/FX45
TCM terminals and data are reference value. Measured between each terminal and ground.
Diagnostic ProcedureACS007FH
1. CHECK CAN COMMUNICATION LINE
Perform the self-diagnosis. Refer to AT- 9 4 , "
SELF-DIAGNOSTIC RESULT MODE" , AT- 1 0 3 , "TCM SELF-
DIAGNOSTIC PROCEDURE (NO TOOLS)" .
Is a malfunction in the CAN communication indicated in the results?
YES >> Check CAN communication line. Refer to AT- 1 0 5 , "DTC U1000 CAN COMMUNICATION LINE" .
NO >> GO TO 2.
2. CHECK MANUAL MODE SWITCH CIRCUIT
With CONSULT-II
1. Turn ignition switch ON. (Do not start engine.)
2. Select “ECU INPUT SIGNALS” in “DATA MONITOR” mode for
“TRANSMISSION” with CONSULT-II.
3. Read out ON/OFF switching action of the “MANU MODE
SW”,“NON M-MODE SW”, “UP SW LEVER”, “DOWN SW
LEVER”.
Without CONSULT-II
Drive vehicle in the manual mode, and confirm that the actual gear position and the meter's indication of the
position mutually coincide when the selector lever is shifted to the “+ (up)” or “- (down)” side (1st ⇔ 5th gear).
OK or NG
OK >> GO TO 4.
NG >> GO TO 3.
TerminalWire
colorItem Condition Data (Approx.)
3 L CAN-H – –
8 R CAN-L – –
9GYStarter relaySelector lever in “N” and “P” positions. Battery voltage
Selector lever in other positions. 0V
Item name Condition Display value
MANU MODE SWManual shift gate position (neutral) ON
Other than the above OFF
NON M-MODE SWManual shift gate position OFF
Other than the above ON
UP SW LEVERSelector lever: + side ON
Other than the above OFF
DOWN SW LEVERSelector lever: - side ON
Other than the above OFF
SCIA4988E

DTC P1815 MANUAL MODE SWITCH
AT-177
D
E
F
G
H
I
J
K
L
MA
B
AT
Revision: 2004 November 2004 FX35/FX45
A/T Position IndicatorACS007FJ
DIAGNOSTIC PROCEDURE
1. CHECK INPUT SIGNALS
With CONSULT-II
1. Start engine.
2. Select “MAIN SIGNALS” in “DATA MONITOR” mode for A/T with
CONSULT-II and read out the value of “GEAR”.
3. Drive vehicle in the manual mode, and confirm that the actual
gear position and the meter's indication of the position mutually
coincide when the selector lever is shifted to the “+ (up)” or “-
(down)” side (1st ⇔ 5th gear).
OK or NG
OK >>INSPECTION END
NG >> Check the following items.
A/T Position Indicator Symptom Chart
PCIA0065E
Items Presumed Location of Trouble
The actual gear position does not change, or shifting into the
manual mode is not possible (no gear shifting in the manual mode
possible).
The A/T position indicator is not indicated.Manual mode switch
Refer to AT-172, "
DTC P1815 MANUAL MODE SWITCH" .
A/T main system (Fail-safe function actuated)

Refer to AT- 9 4 , "SELF-DIAGNOSTIC RESULT MODE" .
The actual gear position changes, but the A/T position indicator is
not indicated.Perform the self-diagnosis function.

Refer to AT- 9 4 , "SELF-DIAGNOSTIC RESULT MODE" .
The actual gear position and the indication on the A/T position
indicator do not coincide.Perform the self-diagnosis function.

Refer to AT- 9 4 , "SELF-DIAGNOSTIC RESULT MODE" .
Only a specific position or positions is/are not indicated on the A/T
position indicator.Check the unified meter and A/C amp.
Refer to DI-4, "
COMBINATION METERS" .

AT-178
DTC P1841 ATF PRESSURE SWITCH 1
Revision: 2004 November 2004 FX35/FX45
DTC P1841 ATF PRESSURE SWITCH 1PFP:25240
DescriptionACS007FK
Fail-safe function to detect front brake clutch solenoid valve condition.
CONSULT-II Reference ValueACS007FL
On Board Diagnosis LogicACS007FM

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

Diagnostic trouble code “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 CauseACS007FN

ATF pressure switch 1

Harness or connectors
(Switch circuit is open or shorted.)
DTC Confirmation ProcedureACS007FO
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
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 (P1841) is detected, go to AT- 1 7 9 , "
Diagnostic Procedure" .
If DTC (P1757) is detected, go to AT- 1 5 7 , "
Diagnostic Procedure" .
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
SAT014K

DTC P1841 ATF PRESSURE SWITCH 1
AT-179
D
E
F
G
H
I
J
K
L
MA
B
AT
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

AT-180
DTC P1843 ATF PRESSURE SWITCH 3
Revision: 2004 November 2004 FX35/FX45
DTC P1843 ATF PRESSURE SWITCH 3PFP:25240
DescriptionACS007FQ
Fail-safe function to detect input clutch solenoid valve condition.
CONSULT-II Reference ValueACS007FR
On Board Diagnosis LogicACS007FS

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

Diagnostic trouble code “ATF PRES SW 3/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 3 is
irregular during depressing accelerator pedal. (Other than during shift change)
Possible CauseACS007FT

ATF pressure switch 3

Harness or connectors
(Switch circuit is open or shorted.)
DTC Confirmation ProcedureACS007FU
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
Selector lever: “D” position
Gear position: 3rd
4th Gear (I/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 (P1843) is detected, go to AT- 1 8 1 , "
Diagnostic Procedure" .
If DTC (P1752) is detected, go to AT- 1 5 3 , "
Diagnostic Procedure" .
Item name Condition Display value
ATF PRES SW 3Input clutch engaged. Refer to AT- 2 0
.ON
Input clutch disengaged. Refer to AT- 2 0
.OFF
SAT014K