2004 INFINITI QX56 brake fluid

AT-170
DTC P1772 LOW COAST BRAKE SOLENOID VALVE
Revision: August 20072004 QX56
Diagnostic ProcedureUCS002HH
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 the engine.
4. Read out the value of “ON OFF SOL” 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-169, "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 (ON-OFF display)
ON OFF SOLLow coast brake engaged.
Refer to AT- 2 1
.ON
Low coast brake disengaged.
Refer to AT- 2 1
.OFFSCIA4794E

DTC P1774 LOW COAST BRAKE SOLENOID VALVE FUNCTION
AT-173
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Revision: August 20072004 QX56
Diagnostic ProcedureUCS002H N
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 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 7 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.
Item name Condition Display value
(ON-OFF dis-
play)
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
SCIA4794E

AT-176
DTC P1841 ATF PRESSURE SWITCH 1
Revision: August 20072004 QX56
Diagnostic ProcedureUCS002HT
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 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-175, "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 pin terminals for damage or loose connection with harness connec-
tor.
OK or NG
OK >> GO TO 6.
NG >> Repair or replace damaged parts.
Item name Condition Display value (ON-OFF
display)
ATF PRES
SW 1Front brake engaged. Refer to AT-2 1
.ON
Front brake disengaged. Refer to AT-2 1
.OFFPCIA0067E

TROUBLE DIAGNOSIS FOR SYMPTOMS
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Revision: August 20072004 QX56
5. CHECK SYMPTOM
Check again. Refer to AT- 6 2 , "
Check at Idle" .
OK or NG
OK >>INSPECTION END
NG >> GO TO 6.
6. PERFORM TCM INSPECTION
1. Perform TCM input/output signals inspection. Refer to AT-90, "
TCM Input/Output Signal Reference Val-
ues" .
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)UCS002IM
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 3 , "
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-131, "DTC P1710 A/T FLUID TEMPERATURE
SENSOR CIRCUIT" , AT-115, "DTC P0725 ENGINE SPEED SIGNAL" ., AT- 1 2 9 , "DTC P1705
THROTTLE POSITION SENSOR" , AT-175, "DTC P1841 ATF PRESSURE SWITCH 1" , AT-
151, "DTC P1757 FRONT BRAKE SOLENOID VALVE" , AT- 1 0 3 , "DTC U1000 CAN COMMUNI-
CATION LINE" .
NO >> GO TO 2.
2. ENGINE IDLE SPEED
Check the engine idle speed. Refer to EC-32, "
Idle Speed and Ignition Timing Check" .
OK or NG
OK >> GO TO 3.
NG >> Repair.
3. CHECK CONTROL CABLE
Check the control cable.

Refer to AT- 2 3 4 , "Checking of A/T Position" .
OK or NG
OK >> GO TO 4.
NG >> Adjust control cable. Refer to AT-234, "
Adjustment of A/
T Position" .
LCIA0324E

TROUBLE DIAGNOSIS FOR SYMPTOMS
AT-199
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Revision: August 20072004 QX56
5. DETECT MALFUNCTIONING ITEM
1. Disassemble A/T. Refer to AT- 2 7 3 , "
Disassembly" .
2. Check the following items:
–Reverse brake. Refer to AT-273, "Disassembly" .
OK or NG
OK >> GO TO 9.
NG >> Repair or replace damaged parts.
6. CHECK LINE PRESSURE
Check the line pressure with the engine idling. Refer to AT-59, "
LINE
PRESSURE TEST" .
OK or NG
OK >> GO TO 9.
NG - 1 >> Line pressure high. GO TO 7.
NG - 2 >> Line pressure low. GO TO 8.
7. DETECT MALFUNCTIONING ITEM
1. Check control valve with TCM. Refer to AT-241, "
Control Valve With TCM and A/T Fluid Temperature Sen-
sor 2" .
2. Disassemble A/T. Refer to AT- 2 7 3 , "
Disassembly" .
3. Check the following items:
–Oil pump assembly. Refer to AT-290, "Oil Pump" .
OK or NG
OK >> GO TO 9.
NG >> Repair or replace damaged parts.
8. DETECT MALFUNCTIONING ITEM
1. Check control valve with TCM. Refer to AT-241, "
Control Valve With TCM and A/T Fluid Temperature Sen-
sor 2" .
2. Disassemble A/T. Refer to AT- 2 7 3 , "
Disassembly" .
3. Check the following items:
–Oil pump assembly. Refer to AT-290, "Oil Pump" .
–Power train system. Refer to AT- 2 7 3 , "Disassembly" .
–Transmission case. Refer to AT - 2 7 3 , "Disassembly" .
OK or NG
OK >> GO TO 9.
NG >> Repair or replace damaged parts.
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TROUBLE DIAGNOSIS FOR SYMPTOMS
AT-213
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Revision: August 20072004 QX56
A/T Does Not Shift: D4 → D5UCS002IT
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-203, "Vehicle Cannot Be
Started From D1" .
2. CHECK SELF-DIAGNOSTIC RESULTS
Perform self-diagnosis. Refer to AT- 9 3 , "
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 5 , "DTC P1841 ATF PRESSURE SWITCH 1" ,
AT-181, "
DTC P1845 ATF PRESSURE SWITCH 5" , AT-151, "DTC P1757 FRONT BRAKE
SOLENOID VALVE" , AT-157, "DTC P1762 DIRECT CLUTCH SOLENOID VALVE" , AT-129,
"DTC P1705 THROTTLE POSITION SENSOR" , AT-134, "DTC P1716 TURBINE REVOLUTION
SENSOR" , AT - 11 2 , "DTC P0720 VEHICLE SPEED SENSOR A/T (REVOLUTION SENSOR)" ,
AT-136, "
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 3 , "
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-59, "
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.
SAT6 3 8A
SAT4 9 4G

AT-220
TROUBLE DIAGNOSIS FOR SYMPTOMS
Revision: August 20072004 QX56
Engine Speed Does Not Return to IdleUCS002IX
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-13, "
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 3 , "
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-151, "DTC P1757 FRONT BRAKE SOLENOID
VA LV E" , AT-157, "DTC P1762 DIRECT CLUTCH SOLENOID VALVE" , AT- 1 7 5 , "DTC P1841
ATF PRESSURE SWITCH 1" , AT-181, "DTC P1845 ATF PRESSURE SWITCH 5" , AT-129,
"DTC P1705 THROTTLE POSITION SENSOR" , AT- 11 2 , "DTC P0720 VEHICLE SPEED SEN-
SOR A/T (REVOLUTION SENSOR)" , AT-136, "DTC P1721 VEHICLE SPEED SENSOR MTR" .
NO >> GO TO 3.
3. CHECK A/T FLUID CONDITION
1. Remove oil pan. Refer to AT-241, "
Control Valve With TCM and A/T Fluid Temperature Sensor 2" .
2. Check A/T fluid condition. Refer to AT- 5 8 , "
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-68,
"Symptom Chart" (Symptom No.65).
OK or NG
OK >> GO TO 5.
NG >> Repair or replace damaged parts.
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SCIA5199E

AT-326
ASSEMBLY
Revision: August 20072004 QX56
8. Make sure that brake band does not close turbine revolution
sensor hole.
9. Install control valve with TCM.
a. Install A/T fluid temperature sensor 2 to bracket.
b. Install A/T fluid temperature sensor 2 (with bracket) in control
valve with TCM. Tighten A/T fluid temperature sensor 2 mount-
ing bolt to the specified torque. Refer to AT-261, "
Components"
.
CAUTION:
Adjust bolt hole of bracket to bolt hole of control valve with
TCM.
c. Install O-ring to A/T assembly harness connector.
CAUTION:

Do not reuse O-ring.

Apply ATF to O-ring.
d. Install control valve with TCM in transmission case.
CAUTION:

Make sure that turbine revolution sensor securely installs
turbine revolution sensor hole.

Adjust A/T assembly harness connector of control valve
with TCM to terminal hole of transmission case.

Hang down revolution sensor harness toward outside so
as not to disturb installation of control valve with TCM.
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