2006 INFINITI QX56 engine

AT-166
DTC P1846 ATF PRESSURE SWITCH 6
Revision: November 20092006 QX56
Diagnostic ProcedureECS00CJS
1. CHECK INPUT SIGNAL
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 “D ” position (2nd
3rd gear), and confirm
the ON/OFF actuation of the “ATF PRES SW 6”.
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 6 7 , "
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 items:

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 3 0 , "Control Valve With TCM and A/T Fluid
Temperature Sensor 2" .
NG >> Repair or replace damaged parts.
4. CHECK DTC
Perform “DTC Confirmation Procedure ”.

Refer to AT- 1 6 5 , "DTC Confirmation Procedure" .
OK or NG
OK >> INSPECTION END
NG >> GO TO 2.
Item name Condition Display value
ATF PRES
SW 6 High and low reverse clutch engaged.
Refer to
AT- 2 0
. ON
High and low reverse clutch disengaged.
Refer to AT- 2 0
. OFFPCIA0067E

AT-168
MAIN POWER SUPPLY AND GROUND CIRCUIT
Revision: November 20092006 QX56
TCM terminals and data are reference value. Measured between each terminal and ground.
Diagnostic ProcedureECS00CJU
1. CHECK TCM POWER SOURCE STEP 1
1. Turn ignition switch OFF.
2. Disconnect A/T assembly harness connector.
3. Check voltage between A/T assembly harness connector termi- nals and ground.
OK or NG
OK >> GO TO 2.
NG >> GO TO 3.
2. CHECK TCM POWER SOURCE STEP 2
1. Disconnect A/T assembly harness connector.
2. Turn ignition switch ON. (Do not start engine.)
3. Check voltage between A/T assembly harness connector termi- nals and ground.
OK or NG
OK >> GO TO 4.
NG >> GO TO 3.
Terminal Wire
color Item
ConditionData (Approx.)
1P Power supply
(Memory back-up) Always
Battery voltage
2P Power supply
(Memory back-up)
Always
Battery voltage
5 B Ground Always0V
6 Y/R Power supply –
Battery voltage
– 0V
10 B Ground Always0V
ItemConnector TerminalVoltage
TCM F91 - Ground
Battery voltage
2 - Ground
6 - Ground 0V
SCIA2104E
ItemConnector TerminalVoltage
TCM F441 - Ground
Battery voltage
2 - Ground
6 - Ground
SCIA2105E

CLOSED THROTTLE POSITION AND WIDE OPEN THROTTLE POSITION CIR-CUIT
AT-171
D E
F
G H
I
J
K L
M A
B
AT
Revision: November 2009 2006 QX56
CLOSED THROTTLE POSITION AND WIDE OPEN THROTTLE POSITION CIR-
CUIT
PFP:18002
CONSULT-II Reference ValueECS00CJV
Diagnostic ProcedureECS00CJW
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 THROTTLE POSITION SIGNAL 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. Depress accelerator pedal and read out the value of “CLSD THL
POS ” and “W/O THL POS ”.
OK or NG
OK >> INSPECTION END
NG >> Check the following items. If NG, repair or replace damaged parts.

Perform the self-diagnosis for “ENGINE” with CONSULT-II.

Open circuit or short to ground or short to power in harness or connectors.

Pin terminals for damage or loose connection with harness connector.
Item name Condition Display value
CLSD THL POS Released accelerator pedal.
ON
Fully depressed accelerator pedal. OFF
W/O THL POS Fully depressed accelerator pedal.
ON
Released accelerator pedal. OFF
Accelerator Pedal OperationMonitor Item
CLSD THL POS W/O THL POS
Released ONOFF
Fully depressed OFFON
PCIA0070E

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

TOW MODE SWITCHAT-175
DE
F
G H
I
J
K L
M A
B
AT
Revision: November 2009 2006 QX56
Diagnostic ProcedureECS00CK1
1. CHECK CAN COMMUNICATION LINE
Perform the self-diagnosis. Refer to AT- 8 6 , "
SELF-DIAGNOSTIC RESULT MODE" .
Is any 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 POWER SOURCE
1. Turn ignition switch “ON”. (Do not start engine.)
2. Check the voltage between tow mode switch connector M67 ter- minal 1 and ground.
OK or NG
OK >> INSPECTION END
NG >> GO TO 3.
3. CHECK TOW MODE SWITCH
1. Turn ignition switch “OFF”.
2. Disconnect tow mode switch connector.
3. Check continuity between tow mode switch terminals 1 and 2.
OK or NG
OK >> GO TO 4.
NG >> Repair or replace tow mode switch.
4. DETECT MALFUNCTIONING ITEM
Check the following items. If any items are damaged, repair or replace damaged parts.

Harness for short or open between combination meter connector terminal 35 and tow mode switch con-
nector terminal 1.

Harness for short or open between tow mode switch connector terminal 2 and ground.
OK or NG
OK >> GO TO 5.
NG >> Repair or replace damaged parts.
5. CHECK COMBINATION METER
Check the combination meter. Refer to DI-17, "
How to Proceed With Trouble Diagnosis" .
OK or NG
OK >> INSPECTION END
NO >> Repair or replace damaged parts.
Condition To w m o d e
switch Data (Approx.)
When ignition switch is turned to “ON ” ON
0V
OFF Battery voltage
SCIA5156E
Condition Continuity
Tow mode switch “ON ” Ye s
Tow mode switch “OFF ” No
SCIA5584E

TROUBLE DIAGNOSIS FOR SYMPTOMSAT-179
DE
F
G H
I
J
K L
M A
B
AT
Revision: November 2009 2006 QX56
TCM terminals and data are reference value. Measured between each terminal and ground.
A/T CHECK Indicator Lamp Does Not Come OnECS00CK3
SYMPTOM:
AT CHECK indicator lamp does not come on for about 2 seconds when turning ignition switch to
“ON”.
DIAGNOSTIC PROCEDURE
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 A/T CHECK INDICATOR LAMP CIRCUIT
Check the combination meter. Refer to DI-5, "
COMBINATION METERS" .
OK or NG
OK >> GO TO 3.
NG >> Repair or replace damaged parts.
3. CHECK TCM POWER SUPPLY AND GROUND CIRCUIT
Check TCM power supply and ground circuit. Refer to AT- 1 6 7 , "
MAIN POWER SUPPLY AND GROUND CIR-
CUIT" .
OK or NG
OK >> INSPECTION END
NG >> Repair or replace damaged parts.
Engine Cannot Be Started In “P” or “N” PositionECS00CK4
SYMPTOM:

Engine cannot be started with selector lever in “P” or “N” position.

Engine can be started with selector lever in “D”or “R” position.
DIAGNOSTIC PROCEDURE
1. CHECK SELF-DIAGNOSIS RESULTS
Perform self-diagnosis. Refer to AT- 8 6 , "
SELF-DIAGNOSTIC RESULT MODE" .
Do the self-diagnosis results indicate PNP switch?
YES >> Check the malfunctioning system. Refer to AT- 1 0 5 , "DTC P0705 PARK/NEUTRAL POSITION
SWITCH" .
NO >> GO TO 2.
Terminal Wire
color Item
ConditionData (Approx.)
3 L CAN-H ––
4V K-line (CONSULT-
II signal) The terminal is connected to the data link connector for CONSULT-II
–
7 R Back-up lamp relay Selector lever in "R" position.
0V
Selector lever in other positions. Battery voltage
8 P CAN-L ––

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