2005 INFINITI QX4 check engine

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
D
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G
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MA
B
AT
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

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
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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
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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