2005 INFINITI QX4 engine

AT-166
DTC P1846 ATF PRESSURE SWITCH 6
Revision: October 20052005 QX56
DTC P1846 ATF PRESSURE SWITCH 6PFP:25240
DescriptionECS00CJN
Fail-safe function to detect high and low reverse clutch solenoid valve condition.
CONSULT-II Reference ValueECS00CJO
On Board Diagnosis LogicECS00CJP

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 CauseECS00CJQ

ATF pressure switch 6

Harness or connectors
(The switch circuit is open or shorted.)
DTC Confirmation ProcedureECS00CJR
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- 1 6 7 , "
Diagnostic Procedure" .
If DTC (P1767) is detected, go to AT- 1 5 3 , "
Diagnostic Procedure" .
Item name Condition Display value
ATF PRES SW 6High and low reverse clutch engaged. Refer to AT- 1 9
.ON
High and low reverse clutch disengaged. Refer to AT- 1 9
.OFF
BCIA0030E

DTC P1846 ATF PRESSURE SWITCH 6
AT-167
D
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B
AT
Revision: October 20052005 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-168, "
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 1 , "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 6 , "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.
Refer to AT-1 9
.ON
High and low reverse clutch disengaged.
Refer to AT-1 9
.OFFPCIA0067E

MAIN POWER SUPPLY AND GROUND CIRCUIT
AT-169
D
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B
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Revision: October 20052005 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.
Te r m i n a lWire
colorItem Condition Data (Approx.)
1PPower supply
(Memory back-up)Always Battery voltage
2PPower supply
(Memory back-up)Always Battery voltage
5 B Ground Always 0V
6Y/RPower supply– Battery voltage
–0V
10 B Ground Always 0V
Item ConnectorTe r m i n a l
(Wire color)Vo ltag e
TCM F91 (P) - Ground
Battery voltage
2 (P) - Ground
6 (Y/R) - Ground 0V
SCIA2104E
Item ConnectorTe r m i n a l
(Wire color)Voltage
TCM F441 (P) - Ground
Battery voltage 2 (P) - Ground
6 (Y/R) - Ground
SCIA2105E

AT-172
CLOSED THROTTLE POSITION AND WIDE OPEN THROTTLE POSITION CIR-
CUIT
Revision: October 20052005 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-85, "
SELF-DIAGNOSTIC RESULT MODE" .
Is a malfunction in the CAN communication indicated in the results?
YES >> Check CAN communication line. Refer to AT-95, "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 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

BRAKE SIGNAL CIRCUIT
AT-173
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B
AT
Revision: October 20052005 QX56
BRAKE SIGNAL CIRCUITPFP:25320
CONSULT-II Reference ValueECS00CJX
Diagnostic ProcedureECS00CJY
1. CHECK CAN COMMUNICATION LINE
Perform the self-diagnosis. Refer to AT - 8 5 , "
SELF-DIAGNOSTIC RESULT MODE" .
Is a malfunction in the CAN communication indicated in the results?
YES >> Check CAN communication line. Refer to AT- 9 5 , "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 1 and 2.
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 SWDepressed brake pedal. ON
Released brake pedal. OFF
PCIA0070E
Condition Continuity
When brake pedal is depressed Yes
When brake pedal is released No
SCIA2045E

AT-176
TOW MODE SWITCH
Revision: October 20052005 QX56
Diagnostic ProcedureECS00CK1
1. CHECK CAN COMMUNICATION LINE
Perform the self-diagnosis. Refer to AT-85, "
SELF-DIAGNOSTIC RESULT MODE" .
Is any malfunction in the CAN communication indicated in the results?
YES >> Check CAN communication line. Refer to AT-95, "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 terminal
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 connector M67 ter-
minals 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.
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-180
TROUBLE DIAGNOSIS FOR SYMPTOMS
Revision: October 20052005 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-85, "
SELF-DIAGNOSTIC RESULT MODE" .
Is a malfunction in the CAN communication indicated in the results?
YES >> Check CAN communication line. Refer to AT-95, "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 8 , "
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 5 , "
SELF-DIAGNOSTIC RESULT MODE" .
Do the self-diagnosis results indicate PNP switch?
YES >> Check the malfunctioning system. Refer to AT-104, "DTC P0705 PARK/NEUTRAL POSITION
SWITCH" .
NO >> GO TO 2.
Te r m i n a lWire
colorItem
ConditionData (Approx.)
3 L CAN-H – –
4VK-line (CONSULT-
II signal)The terminal is connected to the data link connector for CONSULT-II –
7 R Back-up lamp relaySelector lever in "R" position. 0V
Selector lever in other positions. Battery voltage
8 P CAN-L – –

TROUBLE DIAGNOSIS FOR SYMPTOMS
AT-183
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Revision: October 20052005 QX56
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 A/T FLUID CONDITION
1. Remove oil pan. Refer to AT-231, "
Control Valve With TCM and A/T Fluid Temperature Sensor 2" .
2. Check A/T fluid condition. Refer to AT- 1 3 , "
Checking A/T Fluid" .
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-60, "
Symp-
tom Chart" (Symptom No.60).
5. CHECK SYMPTOM
Check again. Refer to AT- 5 4 , "
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-82, "
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 5 , "
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-126, "DTC P1710 A/T FLUID TEMPERATURE
SENSOR CIRCUIT" , AT- 11 3 , "DTC P0725 ENGINE SPEED SIGNAL" ., AT- 1 2 3 , "DTC P1705
SAT6 3 8A
SCIA5199E