brake INFINITI QX56 2006 Factory Service Manual

AT-172
BRAKE SIGNAL CIRCUIT
Revision: November 20092006 QX56
BRAKE SIGNAL CIRCUITPFP:25320
CONSULT-II Reference ValueECS00CJX
Diagnostic ProcedureECS00CJY
1. CHECK CAN COMMUNICATION LINE
Perform the self-diagnosis. Refer to AT- 8 6 , "
SELF-DIAGNOSTIC RESULT MODE" .
Is a malfunction in the CAN communication indicated in the results?
YES >> Check CAN communication line. Refer to AT- 9 6 , "DTC U1000 CAN COMMUNICATION LINE" .
NO >> GO TO 2.
2. CHECK STOP LAMP 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 the “BRAKE SW”.
OK or NG
OK >> INSPECTION END
NG >> GO TO 3.
3. CHECK STOP LAMP SWITCH
Check continuity between stop lamp switch harness connector termi-
nals 3 and 4.
Check stop lamp switch after adjusting brake pedal — refer to
BR-6, "
BRAKE PEDAL" .
OK or NG
OK >> INSPECTION END
NG >> Check the following items. If NG, repair or replace dam- aged parts.

Harness for short or open between battery and stop lamp switch.

Harness for short or open between stop lamp switch and combination meter.
Item name Condition Display value
BRAKE SW Depressed brake pedal.
ON
Released brake pedal. OFF
PCIA0070E
ConditionContinuity
When brake pedal is depressed Yes
When brake pedal is released No
WCIA0559E

AT-182
TROUBLE DIAGNOSIS FOR SYMPTOMS
Revision: November 20092006 QX56
3. CHECK A/T FLUID LEVEL
Check A/T fluid level. Refer to AT- 1 2 , "
Checking Automatic Trans-
mission Fluid (ATF)" .
OK or NG
OK >> GO TO 4.
NG >> Refill ATF.
4. CHECK A/T FLUID CONDITION
1. Remove oil pan. Refer to AT- 2 3 0 , "
Control Valve With TCM and A/T Fluid Temperature Sensor 2" .
2. Check A/T fluid condition. Refer to AT- 1 2 , "
Checking Automatic
Transmission Fluid (ATF)" .
OK or NG
OK >> GO TO 5.
NG >> Check the malfunction items. If any items are damaged, repair or replace damaged parts. Refer to AT- 6 1 , "
Symp-
tom Chart" (Symptom No.60).
5. CHECK SYMPTOM
Check again. Refer to AT- 5 5 , "
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- 8 3 , "
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)ECS00CK7
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- 8 6 , "
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- 1 2 7 , "DTC P1710 A/T FLUID TEMPERATURE
SENSOR CIRCUIT" , AT- 11 6 , "DTC P0725 ENGINE SPEED SIGNAL" ., AT- 1 2 4 , "DTC P1705
SAT638A
SCIA5199E

TROUBLE DIAGNOSIS FOR SYMPTOMSAT-183
DE
F
G H
I
J
K L
M A
B
AT
Revision: November 2009 2006 QX56
THROTTLE POSITION SENSOR" , AT- 1 5 9 , "DTC P1841 ATF PRESSURE SWITCH 1" , AT- 1 4 3 ,
"DTC P1757 FRONT BRAKE SOLENOID VALVE" , AT- 9 6 , "DTC U1000 CAN COMMUNICATION
LINE" .
NO >> GO TO 2.
2. ENGINE IDLE SPEED
Check the engine idle speed. Refer to EC-76, "
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 2 7 , "Checking of A/T Position" .
OK or NG
OK >> GO TO 4.
NG >> Adjust control cable. Refer to AT- 2 2 7 , "
Adjustment of A/
T Position" .
4. CHECK A/T FLUID LEVEL
Check the A/T fluid level. Refer to AT- 1 2 , "
Checking Automatic
Transmission Fluid (ATF)" .
OK or NG
OK >> GO TO 5.
NG >> Refill ATF.
5. CHECK LINE PRESSURE
Check line pressure at idle with selector lever in “D” position. Refer
to AT- 5 2 , "
LINE PRESSURE TEST" .
OK or NG
OK >> GO TO 8.
NG - 1 >> Line pressure high: GO TO 6.
NG - 2 >> Line pressure low: GO TO 7.
LCIA0345E
SAT638A
SAT494G

TROUBLE DIAGNOSIS FOR SYMPTOMSAT-187
DE
F
G H
I
J
K L
M A
B
AT
Revision: November 2009 2006 QX56
5. DETECT MALFUNCTIONING ITEM
1. Disassemble A/T. Refer to AT- 2 6 4 , "
Disassembly" .
2. Check the following items:
–Reverse brake. Refer to AT- 2 6 4 , "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- 5 2 , "
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- 2 3 0 , "
Control Valve With TCM and A/T Fluid Temperature Sen-
sor 2" .
2. Disassemble A/T. Refer to AT- 2 6 4 , "
Disassembly" .
3. Check the following items:
–Oil pump assembly. Refer to AT- 2 8 2 , "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- 2 3 0 , "
Control Valve With TCM and A/T Fluid Temperature Sen-
sor 2" .
2. Disassemble A/T. Refer to AT- 2 6 4 , "
Disassembly" .
3. Check the following items:
–Oil pump assembly. Refer to AT- 2 8 2 , "Oil Pump" .
–Power train system. Refer to AT- 2 6 4 , "Disassembly" .
–Transmission case. Refer to AT- 2 6 4 , "Disassembly" .
OK or NG
OK >> GO TO 9.
NG >> Repair or replace damaged parts.
SAT494G

AT-198
TROUBLE DIAGNOSIS FOR SYMPTOMS
Revision: November 20092006 QX56
8. DETECT MALFUNCTIONING ITEM

Check the malfunction items. If any items are damaged, repair or replace damaged parts. Refer to AT- 6 1 ,
"Symptom Chart" (Symptom No.11).
OK or NG
OK >> GO TO 9.
NG >> Repair or replace damaged parts.
9. CHECK SYMPTOM
Check again. Refer to AT- 5 6 , "
Cruise Test - Part 1" , AT- 5 8 , "Cruise Test - Part 2" .
OK or NG
OK >> INSPECTION END
NG >> GO TO 10.
10. PERFORM TCM INSPECTION
1. Perform TCM input/output signals inspection. Refer to AT- 8 3 , "
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.
11 . DETECT MALFUNCTIONING ITEM

Check the malfunction items. If any items are damaged, repair or replace damaged parts. Refer to AT- 6 1 ,
"Symptom Chart" (Symptom No.11).
OK or NG
OK >> GO TO 9.
NG >> Repair or replace damaged parts.
A/T Does Not Shift: D3 → D4ECS00CKD
SYMPTOM:

The vehicle does not shift-up from the D3 to D4 gear at the specified speed.

The vehicle does not shift-up from the D3 to D4 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- 1 8 9 , "
Vehicle Does Not Creep Forward In “D” Position" , AT- 1 9 1 , "Vehicle Cannot Be
Started From D1" .
2. CHECK SELF-DIAGNOSTIC RESULTS
Perform self-diagnosis. Refer to AT- 8 6 , "
SELF-DIAGNOSTIC RESULT MODE" .
Do the self-diagnostic results indicate ATF pressure switch 1, ATF pressure switch 3, front brake solenoid
valve, input clutch solenoid valve, 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- 1 5 9 , "DTC P1841 ATF PRESSURE SWITCH 1" ,
AT- 1 6 1 , "
DTC P1843 ATF PRESSURE SWITCH 3" , AT- 1 3 9 , "DTC P1752 INPUT CLUTCH
SOLENOID VALVE" , AT- 1 4 3 , "DTC P1757 FRONT BRAKE SOLENOID VALVE" , AT- 1 2 4 , "DTC

TROUBLE DIAGNOSIS FOR SYMPTOMSAT-201
DE
F
G H
I
J
K L
M A
B
AT
Revision: November 2009 2006 QX56
A/T Does Not Shift: D4 → D5ECS00CKE
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- 1 8 9 , "
Vehicle Does Not Creep Forward In “D” Position" , AT- 1 9 1 , "Vehicle Cannot Be
Started From D1" .
2. CHECK SELF-DIAGNOSTIC RESULTS
Perform self-diagnosis. Refer to AT- 8 6 , "
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 5 9 , "DTC P1841 ATF PRESSURE SWITCH 1" ,
AT- 1 6 3 , "
DTC P1845 ATF PRESSURE SWITCH 5" , AT- 1 4 3 , "DTC P1757 FRONT BRAKE
SOLENOID VALVE" , AT- 1 4 7 , "DTC P1762 DIRECT CLUTCH SOLENOID VALVE" , AT- 1 2 4 ,
"DTC P1705 THROTTLE POSITION SENSOR" , AT- 1 0 9 , "DTC P0717 TURBINE REVOLUTION
SENSOR" , AT- 111 , "DTC P0720 VEHICLE SPEED SENSOR A/T (REVOLUTION SENSOR)" ,
AT- 1 3 2 , "
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 2 , "
Checking Automatic Trans-
mission Fluid (ATF)" .
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- 5 2 , "
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.
SAT638A
SAT494G

AT-208
TROUBLE DIAGNOSIS FOR SYMPTOMS
Revision: November 20092006 QX56
Engine Speed Does Not Return to IdleECS00CKI
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- 1 2 , "
Checking Automatic Trans-
mission Fluid (ATF)" .
OK or NG
OK >> GO TO 2.
NG >> Refill ATF.
2. CHECK SELF-DIAGNOSTIC RESULTS
Perform self-diagnosis. Refer to AT- 8 6 , "
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- 1 4 3 , "DTC P1757 FRONT BRAKE SOLENOID
VA LV E" , AT- 1 4 7 , "DTC P1762 DIRECT CLUTCH SOLENOID VALVE" , AT- 1 5 9 , "DTC P1841 ATF
PRESSURE SWITCH 1" , AT- 1 6 3 , "DTC P1845 ATF PRESSURE SWITCH 5" , AT- 1 2 4 , "DTC
P1705 THROTTLE POSITION SENSOR" , AT- 111 , "DTC P0720 VEHICLE SPEED SENSOR A/T
(REVOLUTION SENSOR)" , AT- 1 3 2 , "DTC P1721 VEHICLE SPEED SENSOR MTR" .
NO >> GO TO 3.
3. CHECK A/T FLUID CONDITION
1. Remove oil pan. Refer to AT- 2 3 0 , "
Control Valve With TCM and A/T Fluid Temperature Sensor 2" .
2. Check A/T fluid condition. Refer to AT- 5 1 , "
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- 6 1 ,
"Symptom Chart" (Symptom No.65).
OK or NG
OK >> GO TO 5.
NG >> Repair or replace damaged parts.
SAT638A
SCIA5199E

AT-218
TROUBLE DIAGNOSIS FOR SYMPTOMS
Revision: November 20092006 QX56
9. DETECT MALFUNCTIONING ITEM

Check the malfunction items. If any items are damaged, repair or replace damaged parts. Refer to AT- 6 1 ,
"Symptom Chart" (Symptom No.17).
OK or NG
OK >> GO TO 7.
NG >> Repair or replace damaged parts.
Vehicle Does Not Decelerate By Engine BrakeECS00CKN
SYMPTOM:
No engine brake is applied when the gear is shifted from the 22 to 11 .
DIAGNOSTIC PROCEDURE
1. CHECK SELF-DIAGNOSIS RESULTS
Perform self-diagnosis.
Do the self-diagnosis results indicate PNP switch, ATF pressure switch 5?
YES >> Check the malfunctioning system. Refer to AT- 1 0 5 , "DTC P0705 PARK/NEUTRAL POSITION
SWITCH" , AT- 1 6 3 , "DTC P1845 ATF PRESSURE SWITCH 5" .
NO >> GO TO 2.
2. CHECK 1ST POSITION SWITCH CIRCUIT
With CONSULT-II
1. Turn ignition switch “ ON”.
2. Select "ECU INPUT SIGNALS" in "DATA MONITOR" mode for "A/T" with CONSULT-II.
3. Read out "1 POSITION SW" moving switch selector lever to each position.
Without CONSULT-II
1. Turn ignition switch “ ON”. (Do not start engine)
2. Check voltage between A/T device harness connector terminal and ground.
OK or NG
OK >> GO TO 3.
NG >> Repair or replace damaged parts.
Monitor item Condition Display value
1 POSITION SW When setting the selector
lever to "1" position.
ON
When setting selector
lever to other positions. OFF
LCIA0339E
Item Connector No. Terminal No. Condition Data
(Approx.)
1st position switch M203 7 - Ground When setting
the selector
lever to "1"
position.
0V
When setting
selector lever
to other posi-
tions. Battery volt-
age
LCIA0341E

A/T SHIFT LOCK SYSTEMAT-221
DE
F
G H
I
J
K L
M A
B
AT
Revision: November 2009 2006 QX56
A/T SHIFT LOCK SYSTEMPFP:34950
DescriptionECS00ENU

The electrical key interlock mechanism also operates as a shift lock:
With the ignition switch turned to ON, the selector lever cannot be shifted from “P” (parking) to any other
position unless the brake pedal is depressed.
With the key removed, the selector lever cannot be shifted from “P” to any other position.
The key cannot be removed unless the selector lever is placed in “P”.

The shift lock and key interlock mechanisms are controlled by the ON-OFF operation of the shift lock sole-
noid and by the operation of the rotator and slider located inside the key cylinder, respectively.
Shift Lock System Electrical Parts LocationECS00ENV
LCIA0326E

A/T SHIFT LOCK SYSTEMAT-223
DE
F
G H
I
J
K L
M A
B
AT
Revision: November 2009 2006 QX56
Shift Lock Control Unit Reference ValuesECS00ENX
SHIFT LOCK HARNESS CONNECTOR TERMINALS LAYOUT
SHIFT LOCK CONTROL UNIT INSPECTION TABLE
Data are reference values.
NOTE:
Confirm that the pointer swings only momentarily because the output time is so short. If the inspection is done with an oscillo scope, it
should be observed that the power source voltage lasts for 3.5 to 10 ms.
WCIA0550E
TER-
MINAL NO. WIRE
COLOR ITEM
CONDITION VOLTAGE
(Approx.)
1Y/RPower source Ignition switch:
“ON ” Battery voltage
Ignition switch: “OFF ” Battery voltage
2L/R Detention switch (for
key) When selector lever is not in "P" position with key inserted. Battery voltage
Except the above
0V
3GR Detention switch (for
shift) When selector lever is not in "P" position
Battery voltage
Except the above 0V
4 R/G Stop lamp switch When brake pedal is depressed
Battery voltage
When brake pedal is released 0V
5 W/R Vehicle speed signal ——
6 G/R Ignition signal Ignition switch:
“OFF ” 0V
Ignition switch: “ON ” Battery voltage
7 R/W Shift lock solenoid When brake pedal is depressed with ignition switch "ON". 0V
When brake pedal is depressed.
Battery voltage
8 B Ground Always0V
9 G/W Key lock solenoid When the selector lever is set to a position other than the “
P”
position, and the key switch is turned from “ON ” to “OFF ” Battery voltage for
approx. 0.1 sec.
(Note)
Except the above 0V
10 W/G Key unlock solenoid When ignition switch is not in "ON
” position with key inserted. Battery voltage for
approx. 0.1 sec.
(Note)
Except the above 0V