clutch INFINITI QX56 2004 Factory Manual Online

DTC P1841 ATF PRESSURE SWITCH 1
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Revision: August 20072004 QX56
DTC P1841 ATF PRESSURE SWITCH 1PFP:25240
DescriptionUCS002HO
Fail-safe function to detect front brake clutch solenoid valve condition.
CONSULT-II Reference ValueUCS002HP
On Board Diagnosis LogicUCS002HQ

This is not an OBD-II self-diagnostic item.

Diagnostic trouble code “ATF PRES SW 1/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 1 is
irregular during depressing accelerator pedal. (Other than during shift change)
Possible CauseUCS002H R

ATF pressure switch 1

Harness or connectors
(The switch circuit is open or shorted.)
DTC Confirmation ProcedureUCS002HS
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: 3rd

4th Gear (FR/B 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 (P1841) is detected, go to AT-176, "
Diagnostic Procedure" .
If DTC (P1757) is detected, go to AT-152, "
Diagnostic Procedure" .
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
. OFF
BCIA0030E

AT-178
DTC P1843 ATF PRESSURE SWITCH 3
Revision: August 20072004 QX56
DTC P1843 ATF PRESSURE SWITCH 3PFP:25240
DescriptionUCS002HU
Fail-safe function to detect input clutch solenoid valve condition.
CONSULT-II Reference ValueUCS002HV
On Board Diagnosis LogicUCS002HW

This is not an OBD-II self-diagnostic item.

Diagnostic trouble code “ATF PRES SW 3/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 3 is
irregular during depressing accelerator pedal. (Other than during shift change)
Possible CauseUCS002HX

ATF pressure switch 3

Harness or connectors
(The switch circuit is open or shorted.)
DTC Confirmation ProcedureUCS002HY
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: 3rd

4th Gear (I/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 (P1843) is detected, go to AT- 1 7 9 , "
Diagnostic Procedure" .
If DTC (P1752) is detected, go to AT- 1 4 6 , "
Diagnostic Procedure" .
Item name Condition Display value (ON-OFF display)
ATF PRES SW 3Input clutch engaged. Refer to AT- 2 1
.ON
Input clutch disengaged. Refer to AT- 2 1
. OFF
BCIA0030E

DTC P1843 ATF PRESSURE SWITCH 3
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Revision: August 20072004 QX56
Diagnostic ProcedureUCS002HZ
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 3”.
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 8 , "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.
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)
ATF PRES
SW 3Input clutch engaged. Refer to AT-2 1
.ON
Input clutch disengaged. Refer to AT-2 1
.OFFPCIA0067E

DTC P1845 ATF PRESSURE SWITCH 5
AT-181
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Revision: August 20072004 QX56
DTC P1845 ATF PRESSURE SWITCH 5PFP:25240
DescriptionUCS002I0
Fail-safe function to detect direct clutch solenoid valve condition.
CONSULT-II Reference ValueUCS002I1
On Board Diagnosis LogicUCS002I2

This is not an OBD-II self-diagnostic item.

Diagnostic trouble code “ATF PRES SW 5/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 5 is
irregular during depressing accelerator pedal. (Other than during shift change)
Possible CauseUCS002I3

ATF pressure switch 5

Harness or connectors
(The switch circuit is open or shorted.)
DTC Confirmation ProcedureUCS002I4
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: 1st

2nd Gear (D/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 (P1845) is detected, go to AT-182, "
Diagnostic Procedure" .
If DTC (P1762) is detected, go to AT-158, "
Diagnostic Procedure" .
Item name Condition Display value (ON-OFF display)
ATF PRES SW 5Direct clutch engaged. Refer to AT- 2 1
.ON
Direct clutch disengaged. Refer to AT- 2 1
. OFF
BCIA0030E

AT-182
DTC P1845 ATF PRESSURE SWITCH 5
Revision: August 20072004 QX56
Diagnostic ProcedureUCS002I5
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 (1st

2nd gear), and confirm
the ON/OFF actuation of the “ATF PRES SW 5”.
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-181, "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)
ATF PRES
SW 5Direct clutch egaged. Refer to AT-2 1
.ON
Direct clutch disegaged. Refer to AT-2 1
.OFFPCIA0067E

AT-184
DTC P1846 ATF PRESSURE SWITCH 6
Revision: August 20072004 QX56
DTC P1846 ATF PRESSURE SWITCH 6PFP:25240
DescriptionUCS002I6
Fail-safe function to detect high and low reverse clutch solenoid valve condition.
CONSULT-II Reference ValueUCS002I7
On Board Diagnosis LogicUCS002I8

This is not an OBD-II self-diagnostic item.

Diagnostic trouble code “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 CauseUCS002I9

ATF pressure switch 6

Harness or connectors
(The switch circuit is open or shorted.)
DTC Confirmation ProcedureUCS002IA
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 8 5 , "
Diagnostic Procedure" .
If DTC (P1767) is detected, go to AT- 1 6 4 , "
Diagnostic Procedure" .
Item name Condition Display value (ON-OFF display)
ATF PRES SW 6High and low reverse clutch engaged. Refer to AT- 2 1
.ON
High and low reverse clutch disengaged. Refer to AT- 2 1
. OFF
BCIA0030E

DTC P1846 ATF PRESSURE SWITCH 6
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Revision: August 20072004 QX56
Diagnostic ProcedureUCS002IB
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 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 8 4 , "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 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 4 1 , "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 6High and low reverse clutch engaged.
Refer to AT-2 1
.ON
High and low reverse clutch disengaged.
Refer to AT-2 1
.OFF
PCIA0067E

AT-198
TROUBLE DIAGNOSIS FOR SYMPTOMS
Revision: August 20072004 QX56
Vehicle Does Not Creep Backward In “R” PositionUCS002IN
SYMPTOM:
The vehicle does not creep in the “R” position. Or an extreme lack of acceleration is observed.
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 accelerator pedal position sensor, ATF pressure switch 6, high and low
reverse clutch solenoid valve, CAN communication line, PNP switch?
YES >> Check the malfunctioning system. Refer to AT - 1 2 9 , "DTC P1705 THROTTLE POSITION SEN-
SOR" , AT - 1 8 4 , "DTC P1846 ATF PRESSURE SWITCH 6" , AT-163, "DTC P1767 HIGH AND
LOW REVERSE CLUTCH SOLENOID VALVE" , AT-103, "DTC U1000 CAN COMMUNICATION
LINE" , AT-109, "DTC P0705 PARK/NEUTRAL POSITION SWITCH" .
NO >> GO TO 2.
2. CHECK CONTROL CABLE
Check the control cable.

Refer to AT-234, "Checking of A/T Position" .
OK or NG
OK >> GO TO 3.
NG >> Adjust control cable. Refer to AT-234, "
Adjustment of A/
T Position" .
3. CHECK A/T FLUID LEVEL
Check A/T fluid level. Refer to AT-13, "
Checking A/T Fluid" .
OK or NG
OK >> GO TO 4.
NG >> Refill ATF.
4. CHECK STALL TEST
Check stall revolution with selector lever in “1” and “R” positions.
Refer to AT-58, "
STALL TEST" .
OK or NG
OK >> GO TO 6.
OK in “1” position, NG in “R” position>>GO TO 5.
NG in both “1” and “R” positions>>GO TO 8.
LCIA0324E
SAT6 3 8A
SAT4 9 3G

AT-206
TROUBLE DIAGNOSIS FOR SYMPTOMS
Revision: August 20072004 QX56
12. 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.23).
OK or NG
OK >> GO TO 10.
NG >> Repair or replace damaged parts.
A/T Does Not Shift: D1 → D2UCS002IQ
SYMPTOM:
The vehicle does not shift-up from the D1 to D2 gear at the specified speed.
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-201, "
Vehicle Does Not Creep Forward In “D” Position" , AT - 2 0 3 , "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 5, direct clutch solenoid valve, accelerator pedal
position sensor, vehicle speed sensor A/T (revolution sensor) and vehicle speed sensor MTR?
YES >> Check the malfunctioning system. Refer to AT-181, "DTC P1845 ATF PRESSURE SWITCH 5" ,
AT-157, "
DTC P1762 DIRECT CLUTCH SOLENOID VALVE" , AT-129, "DTC P1705 THROTTLE
POSITION SENSOR" , AT-112, "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-13, "
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- 5 9 , "
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-208
TROUBLE DIAGNOSIS FOR SYMPTOMS
Revision: August 20072004 QX56
10. PERFORM TCM INSPECTION
1. Perform TCM input/output signals inspection. Refer to AT- 9 0 , "
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-68,
"Symptom Chart" (Symptom No.10).
OK or NG
OK >> GO TO 9.
NG >> Repair or replace damaged parts.
A/T Does Not Shift: D2 → D3UCS002IR
SYMPTOM:
The vehicle does not shift-up from D2 to D3 gear at the specified speed.
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-201, "
Vehicle Does Not Creep Forward In “D” Position" , AT - 2 0 3 , "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 6, high and low reverse clutch solenoid valve,
accelerator pedal position sensor, vehicle speed sensor A/T (revolution sensor) and vehicle speed sensor
MTR?
YES >> Check the malfunctioning system. Refer to AT-184, "DTC P1846 ATF PRESSURE SWITCH 6" ,
AT-163, "
DTC P1767 HIGH AND LOW REVERSE CLUTCH SOLENOID VALVE" , AT-129, "DTC
P1705 THROTTLE POSITION 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-13, "
Checking A/T Fluid" .
OK or NG
OK >> GO TO 4.
NG >> Refill ATF.
SAT6 3 8A