2007 INFINITI QX56 check engine

TROUBLE DIAGNOSIS
AT-49
< SERVICE INFORMATION >
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44-3Part 2
AT- 5 8
o AT- 1 7 7 , "Vehicle Cannot Be Started from D1"
o AT- 1 7 9 , "A/T Does Not Shift: D1→ D2"
o AT- 1 8 1 , "A/T Does Not Shift: D2→ D3"
o AT- 1 8 3 , "A/T Does Not Shift: D3→ D4"
Part 3
AT- 5 9
o AT- 1 9 2 , "A/T Does Not Shift: 5th gear → 4th gear"
o AT- 1 9 4 , "A/T Does Not Shift: 4th gear → 3rd gear"
o AT- 1 9 6 , "A/T Does Not Shift: 3rd gear → 2nd gear"
o AT- 1 9 7 , "A/T Does Not Shift: 2nd gear → 1st gear"
o AT- 1 9 9 , "Vehicle Does Not Decelerate By Engine Brake"
o Perform self-diagnostics Enter checks for detected items. AT- 8 3
o AT- 9 1
o AT- 9 4
o AT- 9 8
o AT- 9 9
o AT- 1 0 3
o AT- 1 0 5
o AT- 1 0 9
o AT- 111
o AT- 11 3
o AT- 11 5
o AT- 11 7
o AT- 11 9
o AT- 1 2 4
o AT- 1 2 6
o AT- 1 2 8
o AT- 1 3 0
o AT- 1 3 2
o AT- 1 3 4
o AT- 1 3 6
o AT- 1 3 8
o AT- 1 4 0
o AT- 1 4 2
o AT- 1 4 4
o AT- 1 4 6
o AT- 1 4 8
o AT- 1 5 0
o AT- 1 5 2
o AT- 1 5 4
o AT- 1 5 6
5o Inspect each system for items found to be NG in the self-diagnostics and repair or replace the malfunction
parts.
6o Perform all road tests and enter the checks again for the required items.AT- 5 1
7o For any remaining NG items, perform the “diagnostics procedure” and repair or replace the malfunction parts.
See the chart for diagnostics by symptoms. (This chart also contains other symptoms and inspection proce-
dures.)AT- 6 0
8o Erase the results of the self-diagnostics from the TCM.AT- 3 9

AT-52
< SERVICE INFORMATION >
TROUBLE DIAGNOSIS
Fluid Condition Check
Inspect the fluid condition.
STALL TEST
Stall Test Procedure
1. Inspect the amount of engine oil. Replenish the engine oil if necessary.
2. Drive for about 10 minutes to warm up the vehicle so that the A/
T fluid temperature is 50 to 80°C (122 to 176°F). Inspect the
amount of ATF. Replenish if necessary.
3. Securely engage the parking brake so that the tires do not turn.
4. Engine start, apply foot brake, and place selector lever in “D”
position.
5. While holding down the foot brake, gradually press down the
accelerator pedal.
6. Quickly read off the stall speed, then quickly remove your foot
from the accelerator pedal.
CAUTION:
Do not hold down the accelerator pedal for more than 5 sec-
onds during this test.
7. Move the selector lever to the “N” position.
8. Cool down the ATF.
CAUTION:
Run the engine at idle for at least one minute.
Fluid condition Conceivable Cause Required Operation
Varnished (viscous
varnish state)Clutch, brake
scorchedReplace the ATF and check the A/T
main unit and the vehicle for mal-
functions (wire harnesses, cooler
pipes, etc.)
Milky white or
cloudyWater in the fluidReplace the ATF and check for plac-
es where water is getting in.
Large amount of
metal powder mixed
inUnusual wear of
sliding parts within
A/TReplace the ATF and check for im-
proper operation of the A/T.
SAT638A
SAT647B
SCIA1224E
Stall speed: 2,500 - 2,800 rpm
SAT514G

TROUBLE DIAGNOSIS
AT-55
< SERVICE INFORMATION >
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ROAD TEST
Description
• The road test inspects overall performance of the A/T and analyzes possible malfunction causes.
• The road test is carried out in the following three stages.
1. Check before engine is started. Refer to AT- 5 5
.
2. Check at idle. Refer to AT- 5 5
3. Cruise test
• Inspect all the items from Part 1 to Part 3. Refer to AT- 5 6
, AT- 5 8, AT- 5 9.
• Before beginning the road test, check the test procedure and inspection items.
• Test all inspection items until the symptom is uncovered. Diagnose NG items when all road tests are com-
plete.
Check Before Engine Is StartedINFOID:0000000003532249
1.CHECK AT CHECK INDICATOR LAMP
1. Park vehicle on level surface.
2. Move selector lever to “P” position.
3. Turn ignition switch to “OFF” position and wait at least 10 seconds.
4. Turn ignition switch to “ON” position. (Do not start engine.)
Does AT CHECK indicator lamp light up for about 2 seconds?
YES >> 1. Turn ignition switch to “OFF” position.
2. Carry out the self-diagnostics and record all NG items on the diagnostics worksheet. Refer to
AT-83, "
CONSULT-II Function (A/T)".
3. Go to AT-55, "
Check at Idle".
NO >> Stop the road test and go to AT-167, "
A/T Check Indicator Lamp Does Not Come On".
Check at IdleINFOID:0000000003532250
1.CHECK STARTING THE ENGINE
1. Park vehicle on level surface.
2. Move selector lever to “P” or “N” position.
3. Turn ignition switch to “OFF” position.
4. Turn ignition switch to “START” position.
Does the engine start?
YES >> GO TO 2.
NO >> Stop the road test and go to AT-168, "
Engine Cannot Be Started in "P" or "N" Position".
2.CHECK STARTING THE ENGINE
1. Turn ignition switch to “ON” position.
2. Move selector lever in “D”,“4”, “3”, “2”, “1” or “R” position.
Stall speedOil pressure does
not rise higher than
the oil pressure for
idle.Possible causes include a sensor malfunction or malfunction in the pressure adjustment function.
For example
• Accelerator pedal position signal malfunction
• TCM breakdown
• Line pressure solenoid malfunction (shorting, sticking in“ ON” state)
• Pressure regulator valve or plug sticking
• Pilot valve sticking or pilot filter clogged
The pressure rises,
but does not enter
the standard posi-
tion.Possible causes include malfunctions in the pressure supply system and malfunction in the pres-
sure adjustment function.
For example
• Accelerator pedal position signal malfunction
• Line pressure solenoid malfunction (sticking, filter clog)
• Pressure regulator valve or plug sticking
• Pilot valve sticking or pilot filter clogged
Only low for a spe-
cific positionPossible causes include an oil pressure leak in a passage or device related to the position after
the pressure is distributed by the manual valve. Judgement Possible cause

AT-56
< SERVICE INFORMATION >
TROUBLE DIAGNOSIS
3. Turn ignition switch to “START” position.
Does the engine start in either position?
YES >> Stop the road test and go to AT-168, "Engine Cannot Be Started in "P" or "N" Position".
NO >> GO TO 3.
3.CHECK “P” POSITION FUNCTIONS
1. Move selector lever to “P” position.
2. Turn ignition switch to “OFF” position.
3. Release the parking brake.
4. Push the vehicle forward or backward.
5. Engage the parking brake.
When you push the vehicle with disengaging the parking brake, does it move?
YES >> Enter a check mark at “In “P” Position Vehicle Moves When Pushed” on the diagnostics work-
sheet, then continue the road test.
NO >> GO TO 4.
4.CHECK “N” POSITION FUNCTIONS
1. Start the engine.
2. Move selector lever to “N” position.
3. Release the parking brake.
Does vehicle move forward or backward?
YES >> Enter a check mark at “In “N” Position Vehicle Moves” on the diagnostics worksheet, then con-
tinue the road test.
NO >> GO TO 5.
5.CHECK SHIFT SHOCK
1. Engage the brake.
2. Move selector lever to “D” position.
When the transmission is shifted from
“N” to “D”, is there an excessive shock?
YES >> Enter a check mark at “Large Shock ("N" to "D" Position) on the diagnostics worksheet, then con-
tinue the road test.
NO >> GO TO 6.
6.CHECK “R” POSITION FUNCTIONS
1. Engage the brake.
2. Move selector lever to “R” position.
3. Release the brake for 4 to 5 seconds.
Does the vehicle creep backward?
YES >> GO TO 7.
NO >> Enter a check mark at “Vehicle Does Not Creep Backward In "R" Position” on the diagnostics
worksheet, then continue the road test.
7.CHECK “D” POSITION FUNCTIONS
Inspect whether the vehicle creeps forward when the transmission is put into the “D” position.
Does the vehicle creep forward in the
“D” positions?
YES >> Go to AT-56, "Cruise Test - Part 1", AT-58, "Cruise Test - Part 2", and AT-59, "Cruise Test - Part 3".
NO >> Enter a check mark at “Vehicle Does Not Creep Forward in "D" Position” on the diagnostics work-
sheet, then continue the road test.
Cruise Test - Part 1INFOID:0000000003532251
1.CHECK STARTING OUT FROM D1
1. Drive the vehicle for about 10 minutes to warm up the engine oil and ATF.
Appropriate temperature for the ATF: 50 - 80°C (122 - 176°F)
2. Park the vehicle on a level surface.
3. Move selector lever to “P” position.
4. Start the engine.
5. Move selector lever to “D” position.

AT-58
< SERVICE INFORMATION >
TROUBLE DIAGNOSIS
Does it lock-up?
YES >> GO TO 7.
NO >> Enter a check mark at “A/T Does Not Perform Lock-up” on the diagnostics worksheet, then con-
tinue the road test.
7.CHECK LOCK-UP HOLD
Does it maintain lock-up status?
YES >> GO TO 8.
NO >> Enter a check mark at “A/T Does Not Hold Lock-up Condition” on the diagnostics worksheet, then
continue the road test.
8.CHECK LOCK-UP RELEASE
Check lock-up cancellation by depressing brake pedal lightly to decelerate.
With CONSULT-II
Select “TCC SOLENOID 0.00A” with the “MAIN SIGNAL” mode for A/T.
Does lock-up cancel?
YES >> GO TO 9.
NO >> Enter a check mark at “Lock-up Is Not Released” on the diagnostics worksheet, then continue the
road test.
9.CHECK SHIFT-DOWN D5 → D4
Decelerate by pressing lightly on the brake pedal.
With CONSULT-II
Read the gear position and engine speed.
When the A/T shift-down D5
→ D4, does the engine speed drop smoothly back to idle?
YES >> 1. Stop the vehicle.
2. Go to Cruise test - Part 2 (Refer to AT- 5 8
).
NO >> Enter a check mark at “Engine Speed Does Not Return to Idle” on the diagnostics worksheet, then
continue the road test. Go to Cruise test - Part 2 (Refer to AT- 5 8
).
Cruise Test - Part 2INFOID:0000000003532252
1.CHECK STARTING FROM D1
1. Move selector lever the “D” position.
2. Accelerate at half throttle.
With CONSULT-II
Read the gear position.
Does it start from D1?
YES >> GO TO 2.
NO >> Enter a check mark at “Vehicle Cannot Be Started From D1” on the diagnostics worksheet, then
continue the road test.
2.CHECK SHIFT-UP D1 → D2
Press the accelerator pedal down all the way and inspect whether or not the transmission shifts up (D1 → D2)
at the correct speed.
• Refer to AT-59, "
Vehicle Speed When Shifting Gears".
With CONSULT-II
Read the gear position, throttle position and vehicle speed.
Does the A/T shift-up D1
→ D2 at the correct speed?
YES >> GO TO 3.
NO >> Enter a check mark at “Vehicle Does Not Shift: D1 → D2” on the diagnostics worksheet, then con-
tinue the road test.
3.CHECK SHIFT-UP D2 → D3
Press the accelerator pedal down all the way and inspect whether or not the transmission shifts up (D2 → D3)
at the correct speed.

TROUBLE DIAGNOSIS
AT-59
< SERVICE INFORMATION >
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• Refer to AT-59, "Vehicle Speed When Shifting Gears".
With CONSULT-II
Read the gear position, throttle position and vehicle speed.
Does the A/T shift-up D2
→ D3 at the correct speed?
YES >> GO TO 4.
NO >> Enter a check mark at “Vehicle Does Not Shift: D2 → D3” on the diagnostics worksheet, then con-
tinue the road test.
4.CHECK SHIFT-UP D3 → D4 AND ENGINE BRAKE
When the transmission changes speed D3 → D4, return the accelerator pedal.
Does the A/T shift-up D3
→ D4 and apply the engine brake?
YES >> 1. Stop the vehicle.
2. See AT-59, "
Cruise Test - Part 3".
NO >> Enter a check mark at “Vehicle Does Not Shift: D3 → D4” on the diagnostics worksheet, then con-
tinue the road test.
Cruise Test - Part 3INFOID:0000000003532253
1.CHECK SHIFT-DOWN
During D
5 driving, move gear selector from D → 4 → 3 → 2 → 1.
With CONSULT-II
Read the gear position.
Is downshifting correctly performed?
YES >> GO TO 2.
NO >> Enter a check mark at “Vehicle does not shift” at the corresponding position (5th → 4th, 4th → 3rd,
3rd → 2nd, 2nd → 1st) on the diagnostics worksheet, then continue the road test.
2.CHECK ENGINE BRAKE
Does engine braking effectively reduce speed in 1
1 position?
YES >> 1. Stop the vehicle.
2. Carry out the self-diagnostics. Refer to AT-83, "
CONSULT-II Function (A/T)".
NO >> Enter a check mark at “Vehicle Does Not Decelerate By Engine Brake” on the diagnostics work-
sheet, then continue trouble diagnosis.
Vehicle Speed When Shifting GearsINFOID:0000000003532254
NORMAL MODE
• At half throttle, the accelerator opening is 4/8 of the full opening.
TOW MODE
Final
gear
ratioThrottle positionVehicle speed km/h (MPH)
D
1 →D2D2 →D3D3 →D4D4 →D5D5 →D4D4 →D3D3 →D2D2 →D1
2.937Full throttle 70 - 74
(44 - 46)112 - 120
(70 - 75)176 - 186
(110 - 116)249 - 259
(155 - 161)245 - 255
(152 - 159)166 - 176
(103 - 110)100 - 108
(62 - 67)43 - 47
(27 - 30)
Half throttle 46 - 50
(28 - 31)74 - 82
(46 - 51)103 - 113
(64 - 70)135 - 145
(84 - 90)109 - 119
(68 - 74)69 - 79
(43 - 49)44 - 52
(27 - 32)11 - 1 5
(7 - 10)
3.357Full throttle 61 - 65
(38 - 41)97 - 105
(61 - 66)153 - 163
(95 - 102)236 - 246
(147 - 153)232 - 242
(144 - 151)143 - 153
(89 - 95)87 - 95
(54 - 59)43 - 47
(27 - 29)
Half throttle 41 - 45
(26 - 28)66 - 74
(41 - 46)89 - 99
(56 - 62)11 7 - 1 2 7
(73 - 79)95 - 105
(59 - 65)59 - 69
(37 - 43)38 - 46
(24 - 29)11 - 1 5
(7 - 10)
Final
gear
ratioThrottle positionVehicle speed km/h (MPH)
D
1 →D2D2 →D3D3 →D4D4 →D5D5 →D4D4 →D3D3 →D2D2 →D1

TROUBLE DIAGNOSIS
AT-83
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PCONSULT-II Function (A/T)INFOID:0000000003532259
CONSULT-II can display each diagnostic item using the diagnostic test modes shown following.
CONSULT-II REFERENCE VALUE
NOTICE:
1. The CONSULT-II electrically displays shift timing and lock-up timing (that is, operation timing of each sole-
noid).
Check for time difference between actual shift timing and the CONSULT-II display. If the difference is
noticeable, mechanical parts (except solenoids, sensors, etc.) may be malfunctioning. Check mechanical
parts using applicable diagnostic procedures.
2. Shift schedule (which implies gear position) displayed on CONSULT-II and that indicated in Service Man-
ual may differ slightly. This occurs because of the following reasons:
- Actual shift schedule has more or less tolerance or allowance,
- Shift schedule indicated in Service Manual refers to the point where shifts start, and
- Gear position displayed on CONSULT-II indicates the point where shifts are completed.
3. Display of solenoid valves on CONSULT-II changes at the start of shifting, while gear position is displayed
upon completion of shifting (which is computed by TCM).
9 B/R Starter relaySelector lever in “N”,“ P” positions. Battery voltage
Selector lever in other positions. 0V
10 B Ground Always 0V Te r m i n a l
No.Wire
colorItem Condition Data (Pyrex.)
TCM diagnostic mode Description
WORK SUPPORTSupports inspections and adjustments. Commands are transmitted to the TCM for setting the status
suitable for required operation, input/output signals are received from the TCM and received data is
displayed.
SELF-DIAG RESULTS Displays TCM self-diagnosis results.
DATA MONITOR Displays TCM input/output data in real time.
CAN DIAG SUPPORT MNTR The result of transmit/receive diagnosis of CAN communication can be read.
ACTIVE TEST Operation of electrical loads can be checked by sending drive signal to them.
FUNCTION TEST Conducted by CONSULT-II instead of a technician to determine whether each system is “OK” or “NG”.
ECU PART NUMBER TCM part number can be read.
Item name Condition Display value (Approx.)
ATF TEMP SE 1
0°C (32° F) - 20°C (68°F) - 80°C (176°F)3.3 - 2.7 - 0.9 V
ATF TEMP SE 23.3 - 2.5 - 0.7 V
TCC SOLENOIDWhen perform slip lock-up 0.2 - 0.4 A
When perform lock-up 0.4 - 0.6 A
SLCT LVR POSISelector lever in “N”,“P” position. N/P
Selector lever in “R” position. R
Selector lever in “D” position. D
Selector lever in “4” position. 4
Selector lever in “3” position. 3
Selector lever in “2” position. 2
Selector lever in “1” position. 1
VHCL/S SE·A/T During drivingApproximately matches the
speedometer reading.
ENGINE SPEED Engine runningClosely matches the tachometer
reading.

DTC U1000 CAN COMMUNICATION LINE
AT-93
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Diagnosis ProcedureINFOID:0000000003532265
1.CHECK CAN COMMUNICATION CIRCUIT
With CONSULT-II1. Turn ignition switch “ON” and start engine.
2. Select “SELF-DIAG RESULTS” mode for “A/T” with CONSULT-
II.
Is any malfunction of the
“CAN COMM CIRCUIT” indicated?
YES >> Print out CONSULT-II screen, GO TO LAN section.
Refer to LAN-38, "
Precaution When Using CONSULT-
II".
NO >>INSPECTION END
PCIA0061E