2010 INFINITI QX56 brake sensor

TM-80
< COMPONENT DIAGNOSIS >
P1731 1ST ENGINE BRAKING
P1731 1ST ENGINE BRAKING
DescriptionINFOID:0000000005148636
Fail-safe function to prevent sudden decrease in speed by engine brake other than at "1" position.
CONSULT-III Reference Value in Data Monitor ModeINFOID:0000000005148637
On Board Diagnosis LogicINFOID:0000000005148638
• This is not an OBD-II self-diagnostic item.
• Diagnostic trouble code “P1731 1GR E/BRAKING” with CO NSULT-III is detected under the following condi-
tions.
- When TCM does not receive the proper voltage signal from the sensor.
- When TCM monitors ATF pressure switch 2 and solenoid monitor value, and detects as irregular when
engine brake of 1GR acts other than at 1 position.
Possible CauseINFOID:0000000005148639
• Harness or connectors(The sensor circuit is open or shorted.)
• Low coast brake solenoid valve
• ATF pressure switch 2
DTC Confirmation ProcedureINFOID:0000000005148640
NOTE:
If “DTC Confirmation Procedure” has been previously preformed, always turn ignition switch “OFF”
and wait at least 10 seconds before performing the next test.
After the repair, perform the following proc edure to confirm the malfunction is eliminated.
WITH CONSULT-III
1. Turn ignition switch “ON”. (Do not start engine.)
2. Select “DATA MONITOR” mode for “TRANSMISSION” with CONSULT-III.
3. Start engine.
4. Drive vehicle and maintain the following conditions for at least 2 consecutive seconds. ENGINE SPEED: 1,200 rpm
SLCT LVR POSI: “1” position
GEAR: 1st
5. If DTC is detected, go to TM-80, "
Diagnosis Procedure".
Diagnosis ProcedureINFOID:0000000005148641
1.CHECK INPUT SIGNALS
With CONSULT-III
1. Start the engine.
2. Select “SELECTION FROM MENU” in “DATA MONITOR” for "TRANSMISSION" with CONSULT-III"
3. Drive vehicle in the “1” position (1GR), and confir m the ON/OFF actuation of “ATF PRES SW 2” and "ON
OFF SOL".
Item name Condition Display value
ON OFF SOL Low coast brake engaged. Refer to
TM-9
.O N
Low coast brake disengaged. Refer to TM-9
.O FF
ATF PRES SW 2 Low coast brake engaged. Refer to
TM-9
.O N
Low coast brake disengaged. Refer to TM-9
.O FF
Revision: April 20092010 QX56

P1731 1ST ENGINE BRAKINGTM-81
< COMPONENT DIAGNOSIS >
CEF
G H
I
J
K L
M A
B
TM
N
O P
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 TM-94, "
Diagnosis Procedure".
OK or NG
OK >> GO TO 3.
NG >> Repair or replace damaged parts.
3.DETECT MALFUNCTIONING ITEM
Check the following items:
• The 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 TM-172, "Control Valve with TCM and A/T Fluid
Temperature Sensor 2 and Plug".
NG >> Repair or replace damaged parts.
4.CHECK DTC
Perform “DTC Confirmation Procedure”.
• Refer to TM-80, "
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
TM-9
.O N
Low coast brake disengaged. Refer to TM-9
.O FF
ATF PRES SW 2 Low coast brake engaged. Refer to
TM-9
.O N
Low coast brake disengaged. Refer to TM-9
.O FF
Revision: April 20092010 QX56

TM-84
< COMPONENT DIAGNOSIS >
P1757 FRONT BRAKE SOLENOID
P1757 FRONT BRAKE SOLENOID
DescriptionINFOID:0000000005148648
Front brake solenoid valve is controlled by the TCM in response to signals sent from the transmission range
switch, output speed sensor and accelerator pedal positi on sensor. Gears will then be shifted to the optimum
position.
CONSULT-III Reference Value in Data Monitor ModeINFOID:0000000005148649
On Board Diagn osis LogicINFOID:0000000005148650
• This is an OBD-II self-diagnostic item.
• Diagnostic trouble code “P1757 FR BRAKE SOLENOID” with CONSULT-III 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 CauseINFOID:0000000005148651
• Harness or connectors (The solenoid circuit is open or shorted.)
• Front brake solenoid valve
DTC Confirmation ProcedureINFOID:0000000005148652
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 proc edure to confirm the malfunction is eliminated.
WITH CONSULT-III
1. Turn ignition switch “ON”. (Do not start engine.)
2. Select “DATA MONITOR” mode for “TRANSMISSION” with CONSULT-III.
3. Start engine.
4. Drive vehicle and maintain the following conditions for at least 5 consecutive seconds. ACCELE POSI: 1.5/8 - 2.0/8
SLCT LVR POSI: “D” position
GEAR: 3rd ⇒ 4th (FR/B ON/OFF)
Driving location: Driving the vehicle uphill (increased engine load) will help maintain the driving
conditions required for this test.
5. If DTC is detected go to TM-84, "
Diagnosis Procedure".
WITH GST
Follow the procedure “With CONSULT-III”.
Diagnosis ProcedureINFOID:0000000005148653
1.CHECK INPUT SIGNAL
With CONSULT-III
1. Turn ignition switch “ON”.
2. Select “MAIN SIGNALS” in “DATA MONITO R” mode for “TRANSMISSION” with CONSULT-III.
3. Start engine.
4. Read out the value of “FR/B SOLENOID” while driving.
Item name Condition Display value (Approx.)
FR/B SOLENOID Front brake engaged. Refer to
TM-9
. 0.6 - 0.8 A
Front brake disengaged. Refer to TM-9
. 0 - 0.05 A
Revision: April 20092010 QX56

P1757 FRONT BRAKE SOLENOIDTM-85
< COMPONENT DIAGNOSIS >
CEF
G H
I
J
K L
M A
B
TM
N
O P
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 TM-94, "
Diagnosis Procedure".
OK or NG
OK >> GO TO 3.
NG >> Repair or replace damaged parts.
3.DETECT MALFUNCTIONING ITEM
Check the following items:
• The 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 TM-172, "Control Valve with TCM and A/T Fluid
Temperature Sensor 2 and Plug".
NG >> Repair or replace damaged parts.
4.CHECK DTC
Perform “DTC Confirmation Procedure”.
• Refer to TM-84, "
DTC Confirmation Procedure".
OK or NG
OK >> INSPECTION END
NG >> GO TO 2.
Item name Condition Display value (Approx.)
FR/B SOLENOID Front brake engaged. Refer to TM-9
.
0.6 - 0.8 A
Front brake disengaged. Refer to TM-9
. 0 - 0.05 A
Revision: April 20092010 QX56

TM-90
< COMPONENT DIAGNOSIS >
P1772 LOW COAST BRAKE SOLENOID
P1772 LOW COAST BRAKE SOLENOID
DescriptionINFOID:0000000005148666
Low coast brake solenoid valve is turned “ON” or “OFF” by the TCM in response to signals sent from the trans-
mission range switch, output speed sensor and accelerator pedal position sensor. Gears will then be shifted to
the optimum position.
CONSULT-III Reference Value in Data Monitor ModeINFOID:0000000005148667
On Board Diagn osis LogicINFOID:0000000005148668
• This is an OBD-II self-diagnostic item.
• Diagnostic trouble code “P1772 L C BRAKE SOLENOID” with CONSULT-III is detected when TCM detects
an improper voltage drop when it tries to operate the solenoid valve.
Possible CauseINFOID:0000000005148669
• Harness or connectors (The solenoid circuit is open or shorted.)
• Low coast brake solenoid valve
DTC Confirmation ProcedureINFOID:0000000005148670
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 proc edure to confirm the malfunction is eliminated.
WITH CONSULT-III
1. Turn ignition switch “ON”. (Do not start engine.)
2. Select “DATA MONITOR” mode for “ENGINE” with CONSULT-III.
3. Start engine.
4. Drive vehicle and maintain the following conditions for at least 5 consecutive seconds.
SLCT LVR POSI: “1” or “2”
GEAR: “1st” or “2nd” (LC/B ON/OFF)
5. If DTC is detected, go to TM-90, "
Diagnosis Procedure".
WITH GST
Follow the procedure “With CONSULT-III”.
Diagnosis ProcedureINFOID:0000000005148671
1.CHECK INPUT SIGNAL
With CONSULT-III
1. Turn ignition switch “ON”.
2. Select “SELECTION FROM MENU” in “DATA MONI TOR” mode for “TRANSMISSION” with CONSULT-III.
3. Start the engine.
4. Read out the value of “ON OFF SOL” while driving.
OK or NG
OK >> GO TO 4.
Item name Condition Display value
ON OFF SOL Low coast brake engaged. Refer to
TM-9
.O N
Low coast brake disengaged. Refer to TM-9
.O FF
Item name Condition Display value
ON OFF SOL Low coast brake engaged. Refer to
TM-9
.O N
Low coast brake disengaged. Refer to TM-9
.O FF
Revision: April 20092010 QX56

P1772 LOW COAST BRAKE SOLENOIDTM-91
< COMPONENT DIAGNOSIS >
CEF
G H
I
J
K L
M A
B
TM
N
O P
NG >> GO TO 2.
2.CHECK TCM POWER SUPPLY AND GROUND CIRCUIT
Check TCM power supply and ground circuit. Refer to TM-94, "
Diagnosis Procedure".
OK or NG
OK >> GO TO 3.
NG >> Repair or replace damaged parts.
3.DETECT MALFUNCTIONING ITEM
Check the following items:
• The 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 TM-172, "Control Valve with TCM and A/T Fluid
Temperature Sensor 2 and Plug".
NG >> Repair or replace damaged parts.
4.CHECK DTC
Perform “DTC Confirmation Procedure”.
• Refer to TM-90, "
DTC Confirmation Procedure".
OK or NG
OK >> INSPECTION END
NG >> GO TO 2.
Revision: April 20092010 QX56

TM-92
< COMPONENT DIAGNOSIS >
P1774 LOW COAST BRAKE SOLENOID
P1774 LOW COAST BRAKE SOLENOID
DescriptionINFOID:0000000005148672
• Low coast brake solenoid valve is turned “ON” or “OFF” by the TCM in response to signals sent from the
transmission rang switch, output speed sensor and accelerator pedal 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 malfunc- tion such as control valve sticking, improper solenoid valve operation.
CONSULT-III Reference Value in Data Monitor ModeINFOID:0000000005148673
On Board Diagn osis LogicINFOID:0000000005148674
• This is an OBD-II self-diagnostic item.
• Diagnostic trouble code “P1774 L C BRAKE SOLENOID” with CONSULT-III 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 CauseINFOID:0000000005148675
• Harness or connectors (The solenoid and switch circuits are open or shorted.)
• Low coast brake solenoid valve
• ATF pressure switch 2
DTC Confirmation ProcedureINFOID:0000000005148676
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 proc edure to confirm the malfunction is eliminated.
WITH CONSULT-III
1. Start engine.
2. Accelerate vehicle to maintain the following conditions.
SLCT LVR POSI: “1” or “2” position
GEAR: “1st” or “2nd” (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 “TRANSMISSION” with CONSULT-III. If DTC (P1774) is detected, refer to TM-93, "
Diagnosis Procedure".
If DTC (P1772) is detected, go to TM-90, "
Diagnosis Procedure".
WITH GST
Follow the procedure “With CONSULT-III”.
Item name Condition Display value
ON OFF SOL Low coast brake engaged. Refer to
TM-9
.O N
Low coast brake disengaged. Refer to TM-9
.O FF
ATF PRES SW 2 Low coast brake engaged. Refer to
TM-9
.O N
Low coast brake disengaged. Refer to TM-9
.O FF
Revision: April 20092010 QX56

P1774 LOW COAST BRAKE SOLENOIDTM-93
< COMPONENT DIAGNOSIS >
CEF
G H
I
J
K L
M A
B
TM
N
O P
Diagnosis ProcedureINFOID:0000000005148677
1.CHECK INPUT SIGNALS
With CONSULT-III
1. Start the engine.
2. Select “SELECTION FROM MENU” in “DATA MONI TOR” mode for “TRANSMISSION” with CONSULT-III.
3. Drive vehicle in the “1” or “2” position (“1
1” or “22” 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 TM-94, "
Diagnosis Procedure".
OK or NG
OK >> GO TO 3.
NG >> Repair or replace damaged parts.
3.DETECT MALFUNCTIONING ITEM
Check the following items:
• The 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 TM-172, "Control Valve with TCM and A/T Fluid
Temperature Sensor 2 and Plug".
NG >> Repair or replace damaged parts.
4.CHECK DTC
Perform “DTC Confirmation Procedure”.
• Refer to TM-92, "
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
TM-9
.O N
Low coast brake disengaged. Refer to TM-9
.O FF
ATF PRES SW 2 Low coast brake engaged. Refer to
TM-9
.O N
Low coast brake disengaged. Refer to TM-9
.O FF
Revision: April 20092010 QX56