2005 INFINITI QX4 engine

AT-184
TROUBLE DIAGNOSIS FOR SYMPTOMS
Revision: October 20052005 QX56
THROTTLE POSITION SENSOR" , AT-160, "DTC P1841 ATF PRESSURE SWITCH 1" , AT-144,
"DTC P1757 FRONT BRAKE SOLENOID VALVE" , AT - 9 5 , "DTC U1000 CAN COMMUNICATION
LINE" .
NO >> GO TO 2.
2. ENGINE IDLE SPEED
Check the engine idle speed. Refer to EC-77, "
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-228, "Checking of A/T Position" .
OK or NG
OK >> GO TO 4.
NG >> Adjust control cable. Refer to AT-228, "
Adjustment of A/
T Position" .
4. CHECK A/T FLUID LEVEL
Check the A/T fluid level. Refer to AT-13, "
Checking A/T Fluid" .
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 1 , "
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
SAT6 3 8A
SAT4 9 4G

AT-188
TROUBLE DIAGNOSIS FOR SYMPTOMS
Revision: October 20052005 QX56
5. DETECT MALFUNCTIONING ITEM
1. Disassemble A/T. Refer to AT-262, "
Disassembly" .
2. Check the following items:
–Reverse brake. Refer to AT-262, "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 1 , "
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 1 , "
Control Valve With TCM and A/T Fluid Temperature Sen-
sor 2" .
2. Disassemble A/T. Refer to AT-262, "
Disassembly" .
3. Check the following items:
–Oil pump assembly. Refer to AT-280, "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 1 , "
Control Valve With TCM and A/T Fluid Temperature Sen-
sor 2" .
2. Disassemble A/T. Refer to AT-262, "
Disassembly" .
3. Check the following items:
–Oil pump assembly. Refer to AT-280, "Oil Pump" .
–Power train system. Refer to AT-262, "Disassembly" .
–Transmission case. Refer to AT-262, "Disassembly" .
OK or NG
OK >> GO TO 9.
NG >> Repair or replace damaged parts.
SAT4 9 4G

TROUBLE DIAGNOSIS FOR SYMPTOMS
AT-193
D
E
F
G
H
I
J
K
L
MA
B
AT
Revision: October 20052005 QX56
3. CHECK ACCELERATOR PEDAL POSITION (APP) SENSOR
Check accelerator pedal position (APP) sensor. Refer to AT-123, "
DTC P1705 THROTTLE POSITION SEN-
SOR"
OK or NG
OK >> GO TO 4.
NG >> Repair or replace accelerator pedal position (APP) sensor.
4. 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 5.
NG >> Refill ATF.
5. CHECK LINE PRESSURE
Check line pressure at the engine stall point. Refer to AT-51, "
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.
6. DETECT MALFUNCTIONING ITEM
1. Check control valve with TCM. Refer to AT-231, "
Control Valve With TCM and A/T Fluid Temperature Sen-
sor 2" .
2. Disassemble A/T. Refer to AT- 2 6 2 , "
Disassembly" .
3. Check the following items:
–Oil pump assembly. Refer to AT-280, "Oil Pump" .
OK or NG
OK >> GO TO 8.
NG >> Repair or replace damaged parts.
SAT6 3 8A
SAT4 9 4G

TROUBLE DIAGNOSIS FOR SYMPTOMS
AT-195
D
E
F
G
H
I
J
K
L
MA
B
AT
Revision: October 20052005 QX56
12. DETECT MALFUNCTIONING ITEM

Check the malfunction items. If any items are damaged, repair or replace damaged parts. Refer to AT-60,
"Symptom Chart" (Symptom No.23).
OK or NG
OK >> GO TO 10.
NG >> Repair or replace damaged parts.
A/T Does Not Shift: D1 → D2ECS00CKB
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-190, "
Vehicle Does Not Creep Forward In “D” Position" , AT- 1 9 2 , "Vehicle Cannot Be
Started From D1" .
2. CHECK SELF-DIAGNOSTIC RESULTS
Perform self-diagnosis. Refer to AT- 8 5 , "
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-164, "DTC P1845 ATF PRESSURE SWITCH 5" ,
AT-148, "
DTC P1762 DIRECT CLUTCH SOLENOID VALVE" , AT-123, "DTC P1705 THROTTLE
POSITION SENSOR" , AT- 1 0 8 , "DTC P0720 VEHICLE SPEED SENSOR A/T (REVOLUTION
SENSOR)" , AT-133, "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 3 , "
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-51, "
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-198
TROUBLE DIAGNOSIS FOR SYMPTOMS
Revision: October 20052005 QX56
4. CHECK LINE PRESSURE
Check line pressure at the engine stall point. Refer to AT- 5 1 , "
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.
5. DETECT MALFUNCTIONING ITEM
1. Check control valve with TCM. Refer to AT- 2 3 1 , "
Control Valve With TCM and A/T Fluid Temperature Sen-
sor 2" .
2. Disassemble A/T. Refer to AT-262, "
Disassembly" .
3. Check the following items:
–Oil pump assembly. Refer to AT-280, "Oil Pump" .
OK or NG
OK >> GO TO 7.
NG >> Repair or replace damaged parts.
6. DETECT MALFUNCTIONING ITEM
1. Check control valve with TCM. Refer to AT- 2 3 1 , "
Control Valve With TCM and A/T Fluid Temperature Sen-
sor 2" .
2. Disassemble A/T. Refer to AT-262, "
Disassembly" .
3. Check the following items:
–Oil pump assembly. Refer to AT-280, "Oil Pump" .
–Power train system. Refer to AT-262, "Disassembly" .
–Transmission case. Refer to AT-262, "Disassembly" .
OK or NG
OK >> GO TO 7.
NG >> Repair or replace damaged parts.
7. 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- 5 0 , "
Fluid Condition
Check" .
OK or NG
OK >> GO TO 8.
NG >> GO TO 11.
SAT4 9 4G
SCIA5199E

AT-200
TROUBLE DIAGNOSIS FOR SYMPTOMS
Revision: October 20052005 QX56
P1705 THROTTLE POSITION SENSOR" , AT-108, "DTC P0720 VEHICLE SPEED SENSOR A/T
(REVOLUTION SENSOR)" , AT-133, "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 1 , "
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.
5. DETECT MALFUNCTIONING ITEM
1. Check control valve with TCM. Refer to AT- 2 3 1 , "
Control Valve With TCM and A/T Fluid Temperature Sen-
sor 2" .
2. Disassemble A/T. Refer to AT-262, "
Disassembly" .
3. Check the following items:
–Oil pump assembly. Refer to AT-280, "Oil Pump" .
OK or NG
OK >> GO TO 7.
NG >> Repair or replace damaged parts.
6. DETECT MALFUNCTIONING ITEM
1. Check control valve with TCM. Refer to AT- 2 3 1 , "
Control Valve With TCM and A/T Fluid Temperature Sen-
sor 2" .
2. Disassemble A/T. Refer to AT-262, "
Disassembly" .
3. Check the following items:
–Oil pump assembly. Refer to AT-280, "Oil Pump" .
–Power train system. Refer to AT-262, "Disassembly" .
–Transmission case. Refer to AT-262, "Disassembly" .
OK or NG
OK >> GO TO 7.
NG >> Repair or replace damaged parts.
SAT6 3 8A
SAT4 9 4G

AT-202
TROUBLE DIAGNOSIS FOR SYMPTOMS
Revision: October 20052005 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-190, "
Vehicle Does Not Creep Forward In “D” Position" , AT-192, "Vehicle Cannot Be
Started From D1" .
2. CHECK SELF-DIAGNOSTIC RESULTS
Perform self-diagnosis. Refer to AT- 8 5 , "
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 6 0 , "DTC P1841 ATF PRESSURE SWITCH 1" ,
AT-164, "
DTC P1845 ATF PRESSURE SWITCH 5" , AT-144, "DTC P1757 FRONT BRAKE
SOLENOID VALVE" , AT-148, "DTC P1762 DIRECT CLUTCH SOLENOID VALVE" , AT-123,
"DTC P1705 THROTTLE POSITION SENSOR" , AT-131, "DTC P1716 TURBINE REVOLUTION
SENSOR" , AT-108, "DTC P0720 VEHICLE SPEED SENSOR A/T (REVOLUTION SENSOR)" ,
AT-133, "
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 1 , "
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-204
TROUBLE DIAGNOSIS FOR SYMPTOMS
Revision: October 20052005 QX56
10. PERFORM TCM INSPECTION
1. Perform TCM input/output signals inspection. Refer to AT- 8 2 , "
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-60,
"Symptom Chart" (Symptom No.13).
OK or NG
OK >> GO TO 9.
NG >> Repair or replace damaged parts.
A/T Does Not Perform Lock-upECS00CKF
SYMPTOM:
A/T does not perform lock-up at the specified speed.
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 torque converter clutch solenoid valve, engine speed signal, turbine rev-
olution sensor, accelerator pedal position sensor, CAN communication?
YES >> Check the malfunctioning system. Refer to AT-115, "DTC P0740 TORQUE CONVERTER
CLUTCH SOLENOID VALVE" , AT- 11 3 , "DTC P0725 ENGINE SPEED SIGNAL" , AT-131, "DTC
P1716 TURBINE REVOLUTION SENSOR" , AT-123, "DTC P1705 THROTTLE POSITION SEN-
SOR" , AT- 9 5 , "DTC U1000 CAN COMMUNICATION LINE" .
NO >> GO TO 2.
2. CHECK A/T FLUID LEVEL
Check A/T fluid level. Refer to AT-13, "
Checking A/T Fluid" .
OK or NG
OK >> GO TO 3.
NG >> Refill ATF.
SAT6 3 8A