2005 INFINITI FX35 engine

AT-166
DTC P1772 LOW COAST BRAKE SOLENOID VALVE
Revision: 2005 July 2005 FX
DTC P1772 LOW COAST BRAKE SOLENOID VALVEPFP:31940
DescriptionACS002Q0
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 ValueACS003KP
On Board Diagnosis LogicACS002Q1

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 CauseACS002Q2

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

Low coast brake solenoid valve
DTC Confirmation ProcedureACS002Q3
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 “MAIN SIGNALS” in “DATA MONITOR” mode for “A/T” with CONSULT-II.
3. Touch “START”.
4. Start engine.
5. Drive vehicle and maintain the following conditions for at least 5 consecutive seconds.
Selector lever: “M” position
Gear position: “M1-1st” or “M2-2nd” gear (LC/B ON/OFF)
6. If DTC is detected, go to AT- 1 6 7 , "
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 1
.ON
Low coast brake disengaged. Refer to AT- 2 1
.OFF
BCIA0031E

DTC P1772 LOW COAST BRAKE SOLENOID VALVE AT-167
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Revision: 2005 July 2005 FX
Diagnostic ProcedureACS002Q4
1. CHECK INPUT SIGNAL
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 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 8 3 , "
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 the following.

The A/T assembly harness connector pin terminals for damage or loose connection with harness connec-
tor.
OK or NG
OK >> Replace the control valve with TCM. Refer to AT- 2 4 3 , "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 6 , "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 1
.ON
Low coast brake disengaged. Refer to AT- 2 1
.OFF
SCIA4794E

AT-168
DTC P1774 LOW COAST BRAKE SOLENOID VALVE FUNCTION
Revision: 2005 July 2005 FX
DTC P1774 LOW COAST BRAKE SOLENOID VALVE FUNCTIONPFP:31940
DescriptionACS002Q5

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 ValueACS003KQ
On Board Diagnosis LogicACS002Q6

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 CauseACS002Q7

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

Low coast brake solenoid valve

ATF pressure switch 2
DTC Confirmation ProcedureACS002Q8
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, go to AT- 1 6 9 , "
Diagnostic Proce-
dure" .
If DTC (P1772) is detected, go to AT- 1 6 7 , "
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 1
.ON
Low coast brake disengaged. Refer to AT- 2 1
.OFF
ATF PRES SW 2 Low coast brake engaged. Refer to
AT- 2 1
.ON
Low coast brake disengaged. Refer to AT- 2 1
.OFF
BCIA0031E

DTC P1774 LOW COAST BRAKE SOLENOID VALVE FUNCTION AT-169
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Revision: 2005 July 2005 FX
Diagnostic ProcedureACS002Q9
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 (“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 TCM POWER SUPPLY AND GROUND CIRCUIT
Check TCM power supply and ground circuit. Refer to AT- 1 8 3 , "
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 the following.

The A/T assembly harness connector pin terminals for damage or loose connection with harness connec-
tor.
OK or NG
OK >> Replace the control valve with TCM. Refer to AT- 2 4 3 , "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 SOL Low coast brake engaged. Refer to
AT- 2 1
.ON
Low coast brake disengaged. Refer to AT- 2 1
.OFF
ATF PRES SW 2 Low coast brake engaged. Refer to
AT- 2 1
.ON
Low coast brake disengaged. Refer to AT- 2 1
.OFF
SCIA4794E

AT-170
DTC P1815 MANUAL MODE SWITCH
Revision: 2005 July 2005 FX
DTC P1815 MANUAL MODE SWITCHPFP:34901
DescriptionACS002QA
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. By CAN communication line. Then manual mode
switch position is indicated on the A/T indicator. For inspection, refer to AT- 1 8 9 , "
A/T INDICATOR CIRCUIT" .
CONSULT-II Reference Value in Data Monitor ModeACS002QB
On Board Diagnosis LogicACS002QC

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

Diagnostic trouble code “P1815 MANU MODE SW/CIR” with CONSULT-II is detected when TCM moni-
tors Manual mode, Non manual mode, Up or Down switch signal, and detects as irregular when impossi-
ble input pattern occurs 1 second or more.
Possible CauseACS002QD

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

Manual mode select switch (Into control device)

Manual mode position select switch (Into control device)
DTC Confirmation ProcedureACS002QE
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 “MAIN SIGNALS” in “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 3 , "
Diagnostic Procedure" .
Item name Condition Display Value
MANU MODE SW Manual shift gate position (neutral) ON
Other than the above OFF
NON M-MODE SW Manual shift gate position OFF
Other than the above ON
UP SW LEVER selector lever: + side ON
Other than the above OFF
DOWN SW LEVER selector lever: - side ON
Other than the above OFF
BCIA0031E

DTC P1815 MANUAL MODE SWITCH AT-173
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Revision: 2005 July 2005 FX
TCM terminals and data are reference value. Measured between each terminal and ground.
Diagnostic ProcedureACS002QF
1. CHECK CAN COMMUNICATION LINE
Perform the self-diagnosis. Refer to AT- 9 3 , "
SELF-DIAGNOSTIC RESULT MODE" .
Is a malfunction in the CAN communication indicated in the results?
YES >> Check CAN communication line. Refer to AT- 1 0 6 , "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 “A/T” with CONSULT-II.
3. Read out ON/OFF switching action of “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.
3. DETECT MALFUNCTIONING ITEM
Check the following items.

Manual mode switch. Refer to AT- 1 7 4 , "Component Inspection" .

Pin terminals for damage or loose connection with harness connector.

Open circuit or short to ground or short to power in harness or connector for A/T device (manual mode
switch).

Unified meter and A/C amp. Refer to DI-5, "COMBINATION METERS" .
OK or NG
OK >> GO TO 4.
NG >> Repair or replace damaged parts.
Terminal Wire
color Item Condition Data (Approx.)
3 L CAN-H – –
8 R CAN-L – –
9GYStarter relay Selector lever in “N” and “P” positions. Battery voltage
Selector lever in other positions. 0V
Item name Condition Display Value
MANU MODE SW Manual shift gate position (neutral) ON
Other than the above OFF
NON M-MODE SW Manual shift gate position OFF
Other than the above ON
UP SW LEVER selector lever: +side ON
Other than the above OFF
DOWN SW LEVER selector lever: -side ON
Other than the above OFF
SCIA4988E

DTC P1841 ATF PRESSURE SWITCH 1 AT-175
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Revision: 2005 July 2005 FX
DTC P1841 ATF PRESSURE SWITCH 1PFP:25240
DescriptionACS002QI
Fail-safe function to detect front brake clutch solenoid valve condition.
CONSULT-II Reference ValueACS003KR
On Board Diagnosis LogicACS002QJ

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 CauseACS002QK

ATF pressure switch 1

Harness or connectors
(Switch circuit is open or shorted.)
DTC Confirmation ProcedureACS002QL
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 6 , "
Diagnostic Procedure" .
If DTC (P1757) is detected, go to AT- 1 5 5 , "
Diagnostic Procedure" .
Item name Condition Display value
ATF PRES SW 1 Front brake engaged. Refer to
AT- 2 1
.ON
Front brake disengaged. Refer to AT- 2 1
.OFF
BCIA0031E

AT-176
DTC P1841 ATF PRESSURE SWITCH 1
Revision: 2005 July 2005 FX
Diagnostic ProcedureACS002QM
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 8 3 , "
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 the following.

The A/T assembly harness connector pin terminals for damage or loose connection with harness connec-
tor.
OK or NG
OK >> Replace the control valve with TCM. Refer to AT- 2 4 3 , "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 5 , "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 1
.ON
Front brake disengaged. Refer to AT- 2 1
.OFF
PCIA0067E