2005 INFINITI QX4 cruise control

TROUBLE DIAGNOSIS FOR SYMPTOMS
AT-201
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Revision: October 20052005 QX56
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.
8. 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.12).
OK or NG
OK >> GO TO 9.
NG >> Repair or replace damaged parts.
9. CHECK SYMPTOM
Check again. Refer to AT- 5 5 , "
Cruise Test - Part 1" , AT- 5 7 , "Cruise Test - Part 2" .
OK or NG
OK >>INSPECTION END
NG >> GO TO 10.
10. 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.
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.12).
OK or NG
OK >> GO TO 9.
NG >> Repair or replace damaged parts.
SCIA5199E

TROUBLE DIAGNOSIS FOR SYMPTOMS
AT-203
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Revision: October 20052005 QX56
5. 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 7.
NG >> Repair or replace damaged parts.
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" .
–Power train system. Refer to AT- 2 6 2 , "Disassembly" .
–Transmission case. Refer to AT - 2 6 2 , "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.
8. 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.
9. CHECK SYMPTOM
Check again. Refer to AT- 5 5 , "
Cruise Test - Part 1" .
OK or NG
OK >>INSPECTION END
NG >> GO TO 10.
SCIA5199E

TROUBLE DIAGNOSIS FOR SYMPTOMS
AT-207
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Revision: October 20052005 QX56
2. 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 3.
NG >> Refill ATF.
3. 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 4.
NG >> GO TO 7.
4. 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.25).
OK or NG
OK >> GO TO 5.
NG >> Repair or replace damaged parts.
5. CHECK SYMPTOM
Check again. Refer to AT- 5 5 , "
Cruise Test - Part 1" .
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.
SAT6 3 8A
SCIA5199E

AT-212
TROUBLE DIAGNOSIS FOR SYMPTOMS
Revision: October 20052005 QX56
4. CHECK CONTROL CABLE
Check the control cable.

Refer to AT-228, "Checking of A/T Position" .
OK or NG
OK >> GO TO 5.
NG >> Adjust control cable. Refer to AT-228, "
Adjustment of A/
T Position" .
5. 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 6.
NG >> GO TO 9.
6. 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.14).
OK or NG
OK >> GO TO 7.
NG >> Repair or replace damaged parts.
7. CHECK SYMPTOM
Check again. Refer to AT-58, "
Cruise Test - Part 3" .
OK or NG
OK >>INSPECTION END
NG >> GO TO 8.
8. 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.
LCIA0345E
SCIA5199E

AT-214
TROUBLE DIAGNOSIS FOR SYMPTOMS
Revision: October 20052005 QX56
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- 5 0 , "
Fluid Condition
Check" .
OK or NG
OK >> GO TO 5.
NG >> GO TO 8.
5. 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.15).
OK or NG
OK >> GO TO 6.
NG >> Repair or replace damaged parts.
6. CHECK SYMPTOM
Check again. Refer to AT-58, "
Cruise Test - Part 3" .
OK or NG
OK >>INSPECTION END
NG >> GO TO 7.
7. 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.
8. 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.15).
OK or NG
OK >> GO TO 6.
NG >> Repair or replace damaged parts.
A/T Does Not Shift: 3rd gear → 2nd gearECS00CKL
SYMPTOM:
When shifted from 33 to 22 position, does not downshift from 3rd to 2nd gears.
SCIA5199E

AT-218
TROUBLE DIAGNOSIS FOR SYMPTOMS
Revision: October 20052005 QX56
4. CHECK CONTROL CABLE
Check the control cable.

Refer to AT-228, "Checking of A/T Position" .
OK or NG
OK >> GO TO 5.
NG >> Adjust control cable. Refer to AT-228, "
Adjustment of A/
T Position" .
5. 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 6.
NG >> GO TO 9.
6. 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.17).
OK or NG
OK >> GO TO 7.
NG >> Repair or replace damaged parts.
7. CHECK SYMPTOM
Check again. Refer to AT-57, "
Cruise Test - Part 2" .
OK or NG
OK >>INSPECTION END
NG >> GO TO 8.
8. 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.
LCIA0345E
SCIA5199E

AT-220
TROUBLE DIAGNOSIS FOR SYMPTOMS
Revision: October 20052005 QX56
3. 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 4.
NG >> Refill ATF.
4. CHECK CONTROL CABLE
Check the control cable.

Refer to AT-228, "Checking of A/T Position" .
OK or NG
OK >> GO TO 5.
NG >> Adjust control cable. Refer to AT-228, "
Adjustment of A/
T Position" .
5. 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 6.
NG >> GO TO 9.
6. 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.53).
OK or NG
OK >> GO TO 7.
NG >> Repair or replace damaged parts.
7. CHECK SYMPTOM
Check again. Refer to AT-58, "
Cruise Test - Part 3" .
OK or NG
OK >>INSPECTION END
NG >> GO TO 8.
SAT6 3 8A
LCIA0345E
SCIA5199E

AUTOMATIC SPEED CONTROL DEVICE (ASCD)
EC-29
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Revision: October 20052005 QX56
AUTOMATIC SPEED CONTROL DEVICE (ASCD)PFP:18930
System DescriptionUBS00KZC
INPUT/OUTPUT SIGNAL CHART
*: This signal is sent to the ECM through CAN communication line
BASIC ASCD SYSTEM
Refer to Owner's Manual for ASCD operating instructions.
Automatic Speed Control Device (ASCD) allows a driver to keep vehicle at predetermined constant speed
without depressing accelerator pedal. Driver can set vehicle speed in advance between approximately 40 km/
h (25 MPH) and 144 km/h (89 MPH).
ECM controls throttle angle of electric throttle control actuator to regulate engine speed.
Operation status of ASCD is indicated by CRUISE indicator and SET indicator in combination meter. If any
malfunction occurs in ASCD system, it automatically deactivates control.
NOTE:
Always drive vehicle in safe manner according to traffic conditions and obey all traffic laws.
SET OPERATION
Press MAIN switch. (The CRUISE indicator in combination meter illuminates.)
When vehicle speed reaches a desired speed between approximately 40 km/h (25 MPH) and 144 km/h (89
MPH), press SET/COAST switch. (Then SET indicator in combination meter illuminates.)
ACCEL OPERATION
If the RESUME/ACCELERATE switch is pressed during cruise control driving, increase the vehicle speed until
the switch is released or vehicle speed reaches maximum speed controlled by the system.
And then ASCD will keep the new set speed.
CANCEL OPERATION
When any of following conditions exist, cruise operation will be canceled.

CANCEL switch is pressed

More than 2 switches at ASCD steering switch are pressed at the same time (Set speed will be cleared)

Brake pedal is depressed

Selector lever is changed to N, P, R position

Vehicle speed decreased to 13 km/h (8 MPH) lower than the set speed

VDC system is operated
When the ECM detects any of the following conditions, the ECM will cancel the cruise operation and inform
the driver by blinking indicator lamp.

Engine coolant temperature is slightly higher than the normal operating temperature, CRUISE lamp may
blink slowly.
When the engine coolant temperature decreases to the normal operating temperature, CRUISE lamp will
stop blinking and the cruise operation will be able to work by pressing SET/COAST switch or RESUME/
ACCELERATE switch.

Malfunction for some self-diagnoses regarding ASCD control: SET lamp will blink quickly.
If MAIN switch is turned to OFF during ASCD is activated, all of ASCD operations will be canceled and vehicle
speed memory will be erased.
Sensor Input signal to ECM ECM function Actuator
ASCD brake switch Brake pedal operation
ASCD vehicle speed controlElectric throttle control
actuator Stop lamp switch Brake pedal operation
ASCD steering switch ASCD steering switch operation
Park/Neutral position (PNP)
switchGear position
Wheel sensor* Vehicle speed
TCM* Powertrain revolution