brake sensor INFINITI QX56 2004 Factory Workshop Manual

AT-88
TROUBLE DIAGNOSIS
Revision: August 20072004 QX56
60
OthersVehicle runs with
transmission in “N”
position.
Refer to AT-194, "In
“N” Position, Vehicle
Moves" .ON vehicle1. PNP switchAT- 1 0 9
2. Fluid level and stateAT-5 8
3. Control cable adjustmentAT- 2 3 4
4. Control valve with TCMAT- 2 4 1
OFF vehicle5. Input clutchAT- 2 9 5
6. Gear systemAT- 2 6 1
7. Direct clutchAT- 3 0 7
8. Reverse brakeAT- 2 7 3
9. Forward one- way clutch (Parts behind drum support is
impossible to perform inspection by disassembly. Refer to
AT-1 8
, AT- 1 9 .)AT- 2 7 3
10. Forward brake (Parts behind drum support is impossible
to perform inspection by disassembly. Refer to AT- 1 8
, AT- 1 9
.)AT- 2 7 3
61Engine does not start
in “N” or “P” position.
Refer to AT-192, "Engine Cannot Be
Started In “P” or “N”
Position" .ON vehicle1. Ignition switch and starterPG-4
, SC-
10
2. Control cable adjustmentAT- 2 3 4
3. PNP switchAT- 1 0 9
62Engine starts in posi-
tions other than “N” or
“P”.ON vehicle1. Ignition switch and starterPG-4
, SC-
10
2. Control cable adjustmentAT- 2 3 4
3. PNP switchAT- 1 0 9
63 Engine stall.ON vehicle1. Fluid level and stateAT-5 8
2. Engine speed signalAT - 11 5
3. Turbine revolution sensorAT- 1 3 4
4. Torque converter clutch solenoid valveAT - 11 8
5. CAN communication lineAT- 1 0 3
6. Control valve with TCMAT- 2 4 1
OFF vehicle 7. Torque converterAT- 2 7 3
64Engine stalls when
select lever shifted “N”
→ “D”, “R”.ON vehicle1. Fluid level and stateAT-5 8
2. Engine speed signalAT - 11 5
3. Turbine revolution sensorAT- 1 3 4
4. Torque converter clutch solenoid valveAT - 11 8
5. CAN communication lineAT- 1 0 3
6. Control valve with TCMAT- 2 4 1
OFF vehicle 7. Torque converterAT- 2 7 3
No. Items Symptom Condition Diagnostic ItemReference
page

TROUBLE DIAGNOSIS
AT-89
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Revision: August 20072004 QX56
65 OthersEngine speed does
not return to idle.
Refer to AT- 2 2 0 ,
"Engine Speed Does
Not Return to Idle" .ON vehicle1. Fluid level and stateAT- 5 8
2. ATF pressure switch 5 and direct clutch solenoid valveAT- 1 8 1,
AT- 1 5 7

3. ATF pressure switch 1 and front brake solenoid valveAT- 1 7 5
,
AT- 1 5 1
4. Accelerator pedal position sensorAT- 1 2 9
5. Vehicle speed sensor A/T and vehicle speed sensor MTRAT- 11 2,
AT- 1 3 6
6. CAN communication lineAT- 1 0 3
7. Control valve with TCMAT- 2 4 1
OFF vehicle8. Front brake (brake band)AT- 2 7 39. Direct clutchAT- 3 0 7
No. Items Symptom Condition Diagnostic ItemReference
page

TROUBLE DIAGNOSIS
AT-97
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Revision: August 20072004 QX56
DATA MONITOR MODE
Operation Procedure
1. Perform “CONSULT-II SETTING PROCEDURE” Refer to AT-93, "CONSULT-II SETTING PROCEDURE"
.
2. Touch “DATA MONITOR”.
NOTE:
When malfunction is detected, CONSULT-II performs
“REAL-TIME DIAGNOSIS”. Also, any malfunction detected
while in this mode will be displayed at real time.
Display Items List
X: Standard, —: Not applicable
BCIA0031E
Monitored item (Unit)Monitor Item Selection
Remarks ECU
INPUT
SIGNALSMAIN SIG-
NALSSELEC-
TION
FROM
MENU
VHCL/S SE·A/T (km/h) X X X Revolution sensor
VHCL/S SE·MTR (km/h) X — X
ACCELE POSI (0.0/8) X — X Accelerator pedal position signal
THROTTLE POSI (0.0/8) X X XDegree of opening for accelerator recognized by
the TCM
For fail-safe operation, the specific value used
for control is displayed.
CLSD THL POS (ON-OFF display) X — X
Signal input with CAN communications
W/O THL POS (ON-OFF display) X — X
BRAKE SW (ON-OFF display) X — X Stop lamp switch
GEAR — X XGear position recognized by the TCM updated
after gear-shifting
ENGINE SPEED (rpm) X X X
TURBINE REV (rpm) X X X
OUTPUT REV (rpm) X X X
GEAR RATIO — X X
TC SLIP SPEED (rpm) — X XDifference between engine speed and torque
converter input shaft speed
F SUN GR REV (rpm) — — X
F CARR GR REV (rpm) — — X
AT F T E M P S E 1 ( V ) X — X
AT F T E M P S E 2 ( V ) X — X
AT F T E M P 1 (°C) — X X
AT F T E M P 2 (°C) — X X
BATTERY VOLT (V) X — X
ATF PRES SW 1 (ON-OFF display) X X X (for FR/B solenoid)
ATF PRES SW 2 (ON-OFF display) X X X (for LC/B solenoid)
ATF PRES SW 3 (ON-OFF display) X X X (for I/C solenoid)

DTC P1730 A/T INTERLOCK
AT-139
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Revision: August 20072004 QX56
DTC P1730 A/T INTERLOCKPFP:00000
DescriptionUCS002FO

Fail-safe function to detect interlock conditions.
On Board Diagnosis LogicUCS002FP

This is an OBD-II self-diagnostic item.

Diagnostic trouble code “A/T INTERLOCK” with CONSULT-II or P1730 without CONSULT-II is detected
when TCM does not receive the proper voltage signal from the sensor and switch.

TCM monitors and compares gear position and conditions of each ATF pressure switch when gear is
steady.
Possible CauseUCS002FQ

Harness or connectors
(The solenoid and switch circuit is open or shorted.)

Low coast brake solenoid valve

ATF pressure switch 2
DTC Confirmation ProcedureUCS002FR
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. Drive vehicle and maintain the following conditions for at least 2
consecutive seconds.
Selector lever: “D” position
5. If DTC is detected, go to AT - 1 4 0 , "
Diagnostic Procedure" .
WITH GST
Follow the procedure “With CONSULT-II”.
BCIA0030E

AT-142
DTC P1731 A/T 1ST ENGINE BRAKING
Revision: August 20072004 QX56
DTC P1731 A/T 1ST ENGINE BRAKINGPFP:00000
DescriptionUCS002FU
Fail-safe function to prevent sudden decrease in speed by engine brake other than at M1 position.
CONSULT-II Reference ValueUCS002FV
On Board Diagnosis LogicUCS002FW

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

Diagnostic trouble code “A/T 1ST E/BRAKING” with CONSULT-II is detected under the following condi-
tions.
–When TCM does not receive the proper voltage signal from the sensor.
–When TCM monitors each ATF pressure switch and solenoid monitor value, and detects as irregular when
engine brake of 1st gear acts other than at 1 position.
Possible CauseUCS002FX

Harness or connectors
(The sensor circuit is open or shorted.)

Low coast brake solenoid valve

ATF pressure switch 2
DTC Confirmation ProcedureUCS002FY
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 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. Drive vehicle and maintain the following conditions for at least 2
consecutive seconds.
ENGINE SPEED: 1,200 rpm
Selector lever: “1” position
Gear position: 1st gear
5. If DTC is detected, go to AT-143, "
Diagnostic Procedure" .
Item name Condition Display value (ON-OFF display)
ON OFF SOLLow coast brake engaged. Refer to AT- 2 1
. ON
Low coast brake disengaged. Refer to AT- 2 1
. OFF
ATF PRES SW 2Low coast brake engaged. Refer to AT- 2 1
. ON
Low coast brake disengaged. Refer to AT- 2 1
. OFF
BCIA0030E

DTC P1731 A/T 1ST ENGINE BRAKING
AT-143
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Revision: August 20072004 QX56
Diagnostic ProcedureUCS002FZ
1. CHECK INPUT SIGNALS
With CONSULT-II
1. Start the engine.
2. Select “ECU INPUT SIGNALS” or “MAIN SIGNALS” in “DATA
MONITOR” mode for “A/T” with CONSULT-II.
3. Drive vehicle in the “M” position (1st gear), and confirm the ON/
OFF actuation of the “ATF PRES SW 2”.
OK or NG
OK >> GO TO 6.
NG >> GO TO 2.
2. CHECK TCM
Perform TCM input/output signals inspection. Refer to AT-90, "
TCM Input/Output Signal Reference Values" .
OK or NG
OK >> GO TO 3.
NG >> GO TO 5.
3. CHECK DTC
Perform “DTC Confirmation Procedure”.

Refer to AT- 1 4 2 , "DTC Confirmation Procedure" .
OK or NG
OK >>INSPECTION END
NG >> GO TO 4.
4. 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 1 , "Control Valve With TCM and A/T Fluid
Temperature Sensor 2" .
NG >> Repair or replace damaged parts.
5. DETECT MALFUNCTIONING ITEM
Check the following items:

Power supply and ground circuit for TCM.

The A/T assembly harness connector terminals for damage or loose connection with harness connector.
OK or NG
OK >> GO TO 6.
NG >> Repair or replace damaged parts.
Item name Condition Display value
(ON-OFF display)
ON OFF
SOLLow coast brake engaged. Refer to AT- 2 1
.ON
Low coast brake disengaged. Refer to AT- 2 1
.OFF
ATF PRES
SW 2Low coast brake engaged. Refer to AT- 2 1
.ON
Low coast brake disengaged. Refer to AT- 2 1
.OFF
PCIA0067E

DTC P1757 FRONT BRAKE SOLENOID VALVE
AT-151
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Revision: August 20072004 QX56
DTC P1757 FRONT BRAKE SOLENOID VALVEPFP:31940
DescriptionUCS002G C
Front brake solenoid valve is controlled 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 ValueUCS002G D
On Board Diagnosis LogicUCS002G E

This is an OBD-II self-diagnostic item.

Diagnostic trouble code “FR/B SOLENOID/CIRC” with CONSULT-II or P1757 without CONSULT-II 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 CauseUCS002GF

Harness or connectors
(The solenoid circuit is open or shorted.)

Front brake solenoid valve
DTC Confirmation ProcedureUCS002GG
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. Turn ignition switch “ON”. (Do not start engine.)
2. Select “DATA MONITOR” mode for “A/T” with CONSULT-II.
3. Start engine.
4. Drive vehicle and maintain the following conditions for at least 5
consecutive seconds.
ACCELE POS: 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.
5. If DTC is detected go to AT- 1 5 2 , "
Diagnostic Procedure" .
WITH GST
Follow the procedure “With CONSULT-II”.
Item name Condition Display value (Approx) (A)
FR/B SOLENOIDFront brake engaged. Refer to AT- 2 1
. 0.6 - 0.8
Front brake disengaged. Refer to AT- 2 1
. 0 - 0.05
BCIA0030E

AT-152
DTC P1757 FRONT BRAKE SOLENOID VALVE
Revision: August 20072004 QX56
Diagnostic ProcedureUCS002GH
1. CHECK INPUT SIGNAL
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 the engine.
4. Read out the value of “FR/B SOLENOID” while driving.
OK or NG
OK >> GO TO 6.
NG >> GO TO 2.
2. CHECK TCM
Perform TCM input/output signals inspection. Refer to AT- 9 0 , "
TCM Input/Output Signal Reference Values" .
OK or NG
OK >> GO TO 3.
NG >> GO TO 5.
3. CHECK DTC
Perform “DTC Confirmation Procedure”.

Refer to AT-151, "DTC Confirmation Procedure" .
OK or NG
OK >>INSPECTION END
NG >> GO TO 4.
4. 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-241, "Control Valve With TCM and A/T Fluid
Temperature Sensor 2" .
NG >> Repair or replace damaged parts.
5. DETECT MALFUNCTIONING ITEM
Check the following items:

Power supply and ground circuit for TCM.

The A/T assembly harness connector terminals for damage or loose connection with harness connector.
OK or NG
OK >> GO TO 6.
NG >> Repair or replace damaged parts.
Item name Condition Display value (Approx)
FR/B SOLE-
NOIDFront brake engaged. Refer to AT-2 1
. 0.6 - 0.8 A
Front brake disengaged. Refer to AT- 2 1
. 0 - 0.05 A
SCIA4793E

AT-154
DTC P1759 FRONT BRAKE SOLENOID VALVE FUNCTION
Revision: August 20072004 QX56
DTC P1759 FRONT BRAKE SOLENOID VALVE FUNCTIONPFP:31940
DescriptionUCS002G I

Front brake solenoid valve is controlled by the TCM in response to signals sent from the PNP switch, vehi-
cle 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 ValueUCS002GJ
On Board Diagnosis LogicUCS002GK

This is an OBD-II self-diagnostic item.

Diagnostic trouble code “FR/B SOLENOID FNCT” with CONSULT-II or P1759 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 1 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 1 is irregular
during releasing accelerator pedal. (Other than during shift change)
Possible CauseUCS002GL

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

Front brake solenoid valve

ATF pressure switch 1
DTC Confirmation ProcedureUCS002GM
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 POS: 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 (P1759) is detected, refer to AT-155, "
Diagnostic Procedure" .
If DTC (P1757) is detected, go to AT- 1 5 2 , "
Diagnostic Procedure" .
If DTC (P1841) is detected, go to AT- 1 7 6 , "
Diagnostic Procedure" .
Item name Condition Display value (Approx)
FR/B SOLENOIDFront brake engaged. Refer to AT- 2 1
. 0.6 - 0.8 A
Front brake disengaged. Refer to AT- 2 1
. 0 - 0.05 A
ATF PRES SW 1Front brake engaged. Refer to AT- 2 1
.ON
Front brake disengaged. Refer to AT- 2 1
. OFF
BCIA0030E

DTC P1759 FRONT BRAKE SOLENOID VALVE FUNCTION
AT-155
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Revision: August 20072004 QX56
WITH GST
Follow the procedure “With CONSULT-II”.
Diagnostic ProcedureUCS002G N
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. Drive vehicle in the “D” position (3rd

4th gear), and confirm
the ON/OFF actuation of the “ATF PRES SW 1” and electrical
current value of “FR/B SOLENOID”.
OK or NG
OK >> GO TO 6.
NG >> GO TO 2.
2. CHECK TCM
Perform TCM input/output signals inspection. Refer to AT-90, "
TCM Input/Output Signal Reference Values" .
OK or NG
OK >> GO TO 3.
NG >> GO TO 5.
3. CHECK DTC
Perform “DTC Confirmation Procedure”.

Refer to AT- 1 5 4 , "DTC Confirmation Procedure" .
OK or NG
OK >>INSPECTION END
NG >> GO TO 4.
4. 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 1 , "Control Valve With TCM and A/T Fluid
Temperature Sensor 2" .
NG >> Repair or replace damaged parts.
Item name Condition Display value (Approx)
FR/B SOLE-
NOIDFront brake engaged. Refer to AT- 2 1
. 0.6 - 0.8 A
Front brake disengaged. Refer to AT- 2 1
. 0 - 0.05 A
ATF PRES
SW 1Front brake engaged. Refer to AT- 2 1
. ON
Front brake disengaged. Refer to AT- 2 1
. OFF
SCIA4796E