2007 INFINITI QX56 check engine

AT-156
< SERVICE INFORMATION >
DTC P1846 ATF PRESSURE SWITCH 6
DTC P1846 ATF PRESSURE SWITCH 6
DescriptionINFOID:0000000003532432
Fail-safe function to detect high and low reverse clutch solenoid valve condition.
CONSULT-II Reference Value in Data Monitor ModeINFOID:0000000003532433
On Board Diagnosis LogicINFOID:0000000003532434
• This is not an OBD-II self-diagnostic item.
• Diagnostic trouble code “P1846 ATF PRES SW 6/CIRC” with CONSULT-II is detected when TCM detects
that actual gear ratio is normal, and relation between gear position and condition of ATF pressure switch 6 is
irregular during depressing accelerator pedal. (Other than during shift change)
Possible CauseINFOID:0000000003532435
• ATF pressure switch 6
• Harness or connectors
(The switch circuit is open or shorted.)
DTC Confirmation ProcedureINFOID:0000000003532436
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: 2nd ⇒ 3rd Gear (HLR/C 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 (P1846) is detected, go to AT-156, "
Diagnosis Procedure".
If DTC (P1767) is detected, go toAT-142, "
Diagnosis Procedure".
Diagnosis ProcedureINFOID:0000000003532437
1.CHECK INPUT SIGNAL
With CONSULT-II
Item name Condition Display value
ATF PRES SW 6High and low reverse clutch engaged. Refer to AT- 2 0
.ON
High and low reverse clutch disengaged. Refer to AT- 2 0
.OFF
BCIA0031E

DTC P1846 ATF PRESSURE SWITCH 6
AT-157
< SERVICE INFORMATION >
D
E
F
G
H
I
J
K
L
MA
B
AT
N
O
P
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-158
.
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 AT-210, "Control Valve with TCM and A/T Fluid Tem-
perature Sensor 2".
NG >> Repair or replace damaged parts.
4.CHECK DTC
Perform “DTC Confirmation Procedure”.
• Refer to AT-156, "
DTC Confirmation Procedure".
OK or NG
OK >>INSPECTION END
NG >> GO TO 2.
Item name Condition Display value
ATF PRES SW
6High and low reverse clutch engaged. Re-
fer to AT- 2 0
.ON
High and low reverse clutch disengaged.
Refer to AT- 2 0
.OFFPCIA0067E

MAIN POWER SUPPLY AND GROUND CIRCUIT
AT-159
< SERVICE INFORMATION >
D
E
F
G
H
I
J
K
L
MA
B
AT
N
O
P
Diagnosis ProcedureINFOID:0000000003532439
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.
3.DETECT MALFUNCTIONING ITEM
Check the following items:
• Harness for short or open between battery and A/T assembly harness connector terminals 1, 2
• Harness for short or open between ignition switch and A/T assembly harness connector terminal 6
• 10A fuse [No. 3, located in the fuse block (J/B)] and 10A fuse (No. 49, located in the IPDM E/R)
• Ignition switch, Refer to PG-3
.
OK or NG
OK >> GO TO 4.
NG >> Repair or replace damaged parts.
4.CHECK TCM GROUND CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect A/T assembly harness connector.
3. Check continuity between A/T assembly harness connector F9
terminals 5, 10 and ground.
If OK, check harness for short to ground and short to power.
OK or NG
OK >> GO TO 5.
NG >> Repair open circuit or short to ground or short to power
in harness or connectors.
5.DETECT MALFUNCTIONING ITEM
Item Connector Terminal Voltage
TCM F91 - Ground
Battery voltage
2 - Ground
6 - Ground 0V
SCIA2104E
Item Connector Terminal Voltage
TCM F91 - Ground
Battery voltage 2 - Ground
6 - Ground
SCIA2105E
Continuity should exist.
SCIA2106E

CLOSED THROTTLE POSITION AND WIDE OPEN THROTTLE POSITION CIR-
CUIT
AT-161
< SERVICE INFORMATION >
D
E
F
G
H
I
J
K
L
MA
B
AT
N
O
P
CLOSED THROTTLE POSITION AND WIDE OPEN THROTTLE POSITION
CIRCUIT
CONSULT-II Reference Value in Data Monitor ModeINFOID:0000000003532440
Diagnosis ProcedureINFOID:0000000003532441
1.CHECK CAN COMMUNICATION LINE
Perform the self-diagnosis. Refer to AT-83, "
CONSULT-II Function (A/T)".
Is a malfunction in the CAN communication indicated in the results?
YES >> Check CAN communication line. Refer to AT- 9 1.
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 POSReleased accelerator pedal. ON
Fully depressed accelerator pedal. OFF
W/O THL POSFully depressed accelerator pedal. ON
Released accelerator pedal. OFF
Accelerator Pedal OperationMonitor Item
CLSD THL POS W/O THL POS
Released ON OFF
Fully depressed OFF ON
PCIA0070E

AT-162
< SERVICE INFORMATION >
BRAKE SIGNAL CIRCUIT
BRAKE SIGNAL CIRCUIT
CONSULT-II Reference Value in Data Monitor ModeINFOID:0000000003532442
Diagnosis ProcedureINFOID:0000000003532443
1.CHECK CAN COMMUNICATION LINE
Perform the self-diagnosis. Refer to AT-83, "
CONSULT-II Function (A/T)".
Is a malfunction in the CAN communication indicated in the results?
YES >> Check CAN communication line. Refer to AT- 9 1.
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 terminals 3 and 4.
Check stop lamp switch after adjusting brake pedal — refer to
BR-5
.
OK or NG
OK >> Check stop lamp switch circuit.
NG >> Repair or replace stop lamp switch.
Item name Condition Display value
BRAKE SWDepressed brake pedal. ON
Released brake pedal. OFF
PCIA0070E
Condition Continuity
When brake pedal is depressed Yes
When brake pedal is released No
WCIA0559E

AT-164
< SERVICE INFORMATION >
TOW MODE SWITCH
Diagnosis Procedure
INFOID:0000000003532446
1.CHECK CAN COMMUNICATION LINE
Perform the self-diagnosis. Refer to AT-83, "
CONSULT-II Function (A/T)".
Is any malfunction in the CAN communication indicated in the results?
YES >> Check CAN communication line. Refer to AT- 9 1.
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 connec-
tor 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-15, "
How to Proceed with Trouble Diagnosis".
OK or NG
OK >>INSPECTION END
NO >> Repair or replace damaged parts.
ConditionTo w m o d e
switchData (Approx.)
When ignition switch is turned to “ON”ON 0V
OFF Battery voltage
SCIA5156E
Condition Continuity
Tow mode switch “ON” Yes
Tow mode switch “OFF” No
SCIA5584E

AT-168
< SERVICE INFORMATION >
TROUBLE DIAGNOSIS FOR SYMPTOMS
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-83, "
CONSULT-II Function (A/T)".
Is a malfunction in the CAN communication indicated in the results?
YES >> Check CAN communication line. Refer to AT- 9 1.
NO >> GO TO 2.
2.CHECK A/T CHECK INDICATOR LAMP CIRCUIT
Check the combination meter. Refer to DI-5
.
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-158
.
OK or NG
OK >>INSPECTION END
NG >> Repair or replace damaged parts.
Engine Cannot Be Started in "P" or "N" PositionINFOID:0000000003532449
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-83, "
CONSULT-II Function (A/T)".
Do the self-diagnosis results indicate PNP switch?
YES >> Check the malfunctioning system. Refer to AT- 9 9.
NO >> GO TO 2.
2.CHECK CONTROL CABLE
Check the control cable.
• Refer to AT-208, "
Checking of A/T Position".
OK or NG
OK >> GO TO 3.
NG >> Adjust control cable. Refer to AT-208, "
Adjustment of A/
T Position".
3.CHECK STARTING SYSTEM
Check the starting system. Refer to SC-9
.
OK or NG
OK >>INSPECTION END
NG >> Repair or replace damaged parts.
In "P" Position, Vehicle Moves When PushedINFOID:0000000003532450
SYMPTOM:
LCIA0345E

TROUBLE DIAGNOSIS FOR SYMPTOMS
AT-171
< SERVICE INFORMATION >
D
E
F
G
H
I
J
K
L
MA
B
AT
N
O
P
DIAGNOSTIC PROCEDURE
1.CHECK SELF-DIAGNOSTIC RESULTS
Perform self-diagnosis. Refer to AT-83, "
CONSULT-II Function (A/T)".
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- 11 9, AT-109, AT- 11 7' AT-150' AT-134' AT- 9 1.
NO >> GO TO 2.
2.ENGINE IDLE SPEED
Check the engine idle speed. Refer to EC-75, "
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-208, "
Checking of A/T Position".
OK or NG
OK >> GO TO 4.
NG >> Adjust control cable. Refer to AT-208, "
Adjustment of A/
T Position".
4.CHECK A/T FLUID LEVEL
Check the A/T fluid level. Refer to AT-13, "
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-51, "
Inspections Before Trouble Diagnosis".
OK or NG
OK >> GO TO 8.
NG - 1 >> Line pressure high: GO TO 6.
NG - 2 >> Line pressure low: GO TO 7.
6.DETECT MALFUNCTIONING ITEM
1. Check control valve with TCM. Refer to AT-210, "
Control Valve with TCM and A/T Fluid Temperature Sen-
sor 2".
2. Disassemble A/T. Refer to AT-240, "
Disassembly".
3. Check the following items:
LCIA0345E
SAT638A
SAT494G