ESP INFINITI QX56 2009 Factory Owners Manual

TM-20
< FUNCTION DIAGNOSIS >
A/T CONTROL SYSTEM
TCM Function
INFOID:0000000003771808
The function of the TCM is to:
 Receive input signals sent from various switches and sensors.
 Determine required line pressure, shifting poi nt, lock-up operation, and engine brake operation.
 Send required output signals to the respective solenoids.
CONTROL SYSTEM OUTLINE
The automatic transmission senses v ehicle operating conditions through vari ous sensors or signals. It always
controls the optimum shift position and reduces shifting and lock-up shocks.
1. Front brake 2. Input clutch 3. Direct clutch
4. High and low reverse clutch 5. Reverse brake 6. Forward brake
7. Low coast brake 8. 1st one-way clutch 9. Forward one-way clutch
10. 3rd one-way clutch 11. Front sun gear 12. Input shaft
13. Mid internal gear 14. Front internal gear 15. Rear carrier
16. Rear sun gear 17. Mid sun gear 18. Front carrier
19. Mid carrier 20. Rear internal gear 21. Output shaft
22. Parking gear 23. Parking pawl
SCIA1519E
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TM-24
< FUNCTION DIAGNOSIS >
A/T CONTROL SYSTEM
The necessary and adequate line pressure for shift change is set.
For this reason, line pressure pattern setting corresponds to input
torque and gearshift selection. Also, line pressure characteristic is
set according to engine speed, during engine brake operation.
At Low Fluid Temperature
When the A/T fluid temperature drops below the prescribed tempera-
ture, in order to speed up the action of each friction element, the line
pressure is set higher than the normal line pressure characteristic.
Shift ControlINFOID:0000000003771812
The clutch pressure control solenoid is controlled by the signals from the switches and sensors. Thus, the
clutch pressure is adjusted to be appropriate to the engine load state and vehicle driving state. It becomes
possible to finely control the clutch hydraulic pressu re with high precision and a smoother shift change charac-
teristic is attained.
SHIFT CHANGE
The clutch is controlled with the optimum timing and oil pressure by the engine speed, engine torque informa-
tion, etc.
Shift Change System Diagram
PCIA0010E
PCIA0011E
PCIA0012E
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A/T SHIFT LOCK SYSTEMTM-29
< FUNCTION DIAGNOSIS >
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A/T SHIFT LOCK SYSTEM
System DescriptionINFOID:0000000003771817
 The electrical key interlock mechanism also operates as a shift lock: With the ignition switch turned to ON, the selector lever cannot be shifted from “P” (parking) to any other
position unless the brake pedal is depressed.
With the key removed, the selector lever c annot be shifted from “P” to any other position.
The key cannot be removed unless the selector lever is placed in “P”.
 The shift lock and key interlock mechanisms are controlled by the ON-OFF operation of the shift lock sole-
noid and by the operation of the rotator and slider located inside the key cylinder, respectively.
Component Parts LocationINFOID:0000000003771818
LCIA0326E
Revision: December 20092009 QX56

TM-30
< FUNCTION DIAGNOSIS >
ON BOARD DIAGNOSTIC (OBD) SYSTEM
ON BOARD DIAGNOSTIC (OBD) SYSTEM
IntroductionINFOID:0000000003771819
The A/T system has two self-diagnostic systems.
The first is the emission-related on board diagnostic syst em (OBD-II) performed by the TCM in combination
with the ECM. The malfunction is indicated by the MI L (malfunction indicator lamp) and is stored as a DTC in
the ECM memory but not the TCM memory.
The second is the TCM original self-diagnosis indicat ed by the A/T CHECK indicator lamp. The malfunction is
stored in the TCM memory. The detected items are ov erlapped with OBD-II self-diagnostic items. For detail,
refer to TM-32, "CONSULT-III Function (TRANSMISSION)"
.
OBD-II Function for A/T SystemINFOID:0000000003771820
The ECM provides emission-related on board diagnostic (O BD-II) functions for the A/T system. One function
is to receive a signal from the TCM used with OBD-relat ed parts of the A/T system. The signal is sent to the
ECM when a malfunction occurs in the corresponding OBD-related part. The other function is to indicate a
diagnostic result by means of the MIL (malfunction indi cator lamp) on the instrument panel. Sensors, switches
and solenoid valves are used as sensing elements.
The MIL automatically illuminates in One or Two Trip Detection Logic when a malfunction is sensed in relation
to A/T system parts.
One or Two Trip Detection Logic of OBD-IIINFOID:0000000003771821
ONE TRIP DETECTION LOGIC
If a malfunction is sensed during the first test drive, the MIL will illuminate and the malfunction will be stored in
the ECM memory as a DTC. The TCM is not provided with such a memory function.
TWO TRIP DETECTION LOGIC
When a malfunction is sensed during the first test drive, it is stored in the ECM memory as a 1st trip DTC
(diagnostic trouble code) or 1st trip freeze frame data. At this point, the MIL will not illuminate. — 1st Trip
If the same malfunction as that experienced during the fi rst test drive is sensed during the second test drive,
the MIL will illuminate. — 2nd Trip
The “Trip” in the “One or Two Trip Detection Logic” means a driving mode in which self-diagnosis is performed
during vehicle operation.
OBD-II Diagnostic Trouble Code (DTC)INFOID:0000000003771822
HOW TO READ DTC AND 1ST TRIP DTC
DTC and 1st trip DTC can be read by the following methods.
( with CONSULT-III or GST) CONSULT-III or GST (Generic Scan Tool) Examples: P0705, P0720 etc.
These DTC are prescribed by SAE J2012.
(CONSULT-III also displays the malfunctioning component or system.)
 1st trip DTC No. is the same as DTC No.
 Output of the diagnostic troubl e code indicates that the indicated circuit has a malfunction. How-
ever, in case of the Mode II and GST, they do not indicate whether the malfunction is still occurring or
occurred in the past and returned to normal.
CONSULT-III can identify them as shown below, therefore, CONSULT-III (if available) is recom-
mended.
Freeze Frame Data and 1st Trip Freeze Frame Data
The ECM has a memory function, which stores the driv ing condition such as fuel system status, calculated
load value, engine coolant temperature, short term f uel trim, long term fuel trim, engine speed and vehicle
speed at the moment the ECM detects a malfunction.
Data which are stored in the ECM memory, along with the 1st trip DTC, are called 1st trip freeze frame data,
and the data, stored together with the DTC data, are called freeze frame data and displayed on CONSULT-III
or GST. The 1st trip freeze frame data can only be disp layed on the CONSULT-III screen, not on the GST. For
detail, refer to TM-30
.
Only one set of freeze frame data (either 1st trip freez e frame data of freeze frame data) can be stored in the
ECM. 1st trip freeze frame data is stored in the ECM me mory along with the 1st trip DTC. There is no priority
for 1st trip freeze frame data and it is updated each time a different 1st trip DTC is detected. However, once
freeze frame data (2nd trip detection/MIL on) is stored in the ECM memory, 1st trip freeze frame data is no
Revision: December 20092009 QX56

DIAGNOSIS SYSTEM (TCM)TM-37
< FUNCTION DIAGNOSIS >
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Diagnosis Procedure without CONSULT-IIIINFOID:0000000004024115
OBD-II SELF-DIAGNOSTIC PROCEDURE (WITH GST)
Refer to EC-72, "Generic Scan Tool (GST) Function".
OBD-II SELF-DIAGNOSTIC PROCEDURE (NO TOOLS)
Refer to EC-55, "Malfunction Indicator Lamp (MIL)".
TCM SELF-DIAGNOSTIC PROCEDURE (NO TOOLS)
Description
When the ignition switch is switched “ON”, the A/T CHECK indicator lamp lights up for 2 seconds. As a method
for locating the suspect circuit, w hen the self-diagnostics start signal is input, the memory for the malfunction
location is output and the A/T CHECK indicator lamp flashes to display the corresponding DTC.
Diagnostic Procedure
1.CHECK A/T CHECK INDICATOR LAMP
1. Start the engine with selector lever in “P” pos ition. Warm engine to normal operating temperature.
2. Turn ignition switch ON and OFF at least twice, then leave it in the OFF position.
3. Wait 10 seconds.
4. Turn ignition switch ON. (Do not start engine.)
Does A/T CHECK indicator lamp come on for about 2 seconds?
YES >> GO TO 2.
NO >> GO TO TM-119, "A/T Check Indicator Lamp Does Not Come On"
.
2.JUDGEMENT PROCEDURE STEP 1
1. Turn ignition switch OFF.
2. Keep pressing shift lock release button.
3. Move selector lever from “P” to “D” position.
4. Release accelerator pedal. (Set the closed throttle position signal “ON”.)
5. Depress brake pedal. (Stop lamp switch signal “ON”.)
6. Turn ignition switch ON. (Do not start engine.)
7. Wait 3 seconds.
8. Move the selector lever from “D” to “3” position.
9. Release brake pedal. (Stop lamp switch signal “OFF”.)
10. Move the selector lever from “3” to “2” position.
11. Depress brake pedal. (Stop lamp switch signal “ON”.)
DTC work support item Description Check item
1ST GR FUNCTN P0731 Following items for “” be confirmed.
 Self-diagnosis status (whether the diagnosis is being performed
or not)
 Self-diagnosis result (OK or NG)
 Input clutch solenoid valve
 Front brake solenoid valve
 Direct clutch solenoid valve
 High and low reverse clutch solenoid valve
 Each clutch
 Hydraulic co ntrol circuit
valve
2ND GR FUNCTN P0732
Following items for “” be confirmed.
 Self-diagnosis status (whether the diagnosis is being performed
or not)
 Self-diagnosis result (OK or NG)
3RD GR FUNCTN P0733 Following items for “” be confirmed.
 Self-diagnosis status (whether the diagnosis is being performed
or not)
 Self-diagnosis result (OK or NG)
4TH GR FUNCTN P0734 Following items for “” be confirmed.
 Self-diagnosis status (whether the diagnosis is being performed
or not)
 Self-diagnosis result (OK or NG)
5TH GR FUNCTN P0735 Following items for “” be confirmed.
 Self-diagnosis status (whether the diagnosis is being performed
or not)
 Self-diagnosis result (OK or NG)
Revision: December 20092009 QX56

TM-38
< FUNCTION DIAGNOSIS >
DIAGNOSIS SYSTEM (TCM)
12. Depress accelerator pedal fully and release it.>> GO TO 3.
3.CHECK SELF-DIAGNOSIS CODE
Check A/T CHECK indicator lamp.
Refer to "Judgement Self-diagnosis Code".
If the system does not go into self-diagnostics. Refer to TM-44, "Diagnosis Procedure"
, TM-94, "Diagnosis
Procedure", TM-95, "Diagnosis Procedure".
>> DIAGNOSIS END
Judgement Self-diagnosis Code
If there is a malfunction, the lamp lights up fo r the time corresponding to the suspect circuit.
Erase Self-diagnosis
 In order to make it easier to find the cause of hard-to-duplicate malfunctions, malfunction information is
stored into the control unit as necessary during use by the user. This memory is not erased no matter how
many times the ignition switch is turned ON and OFF.
 However, this information is erased by turning igni tion switch OFF after executing self-diagnostics or by
erasing the memory using the CONSULT-III.
ABDIA0593GB
Revision: December 20092009 QX56

P0720 OUTPUT SPEED SENSORTM-49
< COMPONENT DIAGNOSIS >
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P0720 OUTPUT SPEED SENSOR
DescriptionINFOID:0000000003771853
The output speed sensor detects the revolution of the idler gear parking pawl lock gear and emits a pulse sig-
nal. The pulse signal is sent to the TC M which converts it into vehicle speed.
CONSULT-III Reference Value in Data Monitor ModeINFOID:0000000003771854
On Board Diagnosis LogicINFOID:0000000003771855
 This is an OBD-II self-diagnostic item.
 Diagnostic trouble code “P0720” with CONSULT-III is detected under the following conditions.
- When TCM does not receive the proper voltage signal from the sensor.
- After ignition switch is turned “ON”, irregular signal input from vehicle speed signal before the vehicle starts
moving.
Possible CauseINFOID:0000000003771856
 Harness or connectors (The sensor circuit is open or shorted.)
 Output speed sensor
 Vehicle speed signal
DTC Confirmation ProcedureINFOID:0000000003771857
CAUTION:
 Always drive vehicle at a safe speed.
 Be careful not to rev engine into the red zone on the tachometer.
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-III
1. Turn ignition switch “ON”. (Do not start engine.)
2. Select “DATA MONITOR” mode for “TRANSMISSION” with CONSULT-III.
3. Drive vehicle and check for an increase of “VHCL/S SE·A/T” value in response to “VHCL/S SE·MTR”
value.
If the check result is NG, go to TM-50, "Diagnosis Procedure"
.
If the check result is OK, go to following step.
4. Select “DATA MONITOR” mode for “ENGINE” with CONSULT-III.
5. Start engine and maintain the following conditions for at least 5 consecutive seconds.
VHCL/S SE-A/T: 30 km/h (19 MPH) or more
ACCELE POSI: More than 1.0/8
SLCT LVR POSI: “D” position
Driving location: Driving the vehic le uphill (increased engine load) will help maintain the driving
conditions required for this test.
If the check result is NG, go to TM-50, "Diagnosis Procedure"
.
If the check result is OK, go to following step.
6. Maintain the following conditions for at least 5 consecutive seconds.
ENGINE SPEED: 3,500 rpm or more
ACCELE POSI: More than 1.0/8
SLCT LVR POSI: “D” position
Driving location: Driving the vehic le uphill (increased engine load) will help maintain the driving
conditions required for this test.
If the check result is NG, go to TM-50, "Diagnosis Procedure"
.
Item name Condition Display value (km/h)
VHCL/S SE·A/T During driving Approximately matches the speedometer reading.
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TM-52
< COMPONENT DIAGNOSIS >
P0725 ENGINE SPEED
P0725 ENGINE SPEED
DescriptionINFOID:0000000003771859
The engine speed signal is sent from the ECM to the TCM.
CONSULT-III Reference Value in Data Monitor ModeINFOID:0000000003771860
On Board Diagnosis LogicINFOID:0000000003771861
 This is not an OBD-II self-diagnostic item.
 Diagnostic trouble code “P0725” with CONSULT-III is detected when TCM does not receive the ignition sig-
nal from ECM during engine cranking or running.
Possible CauseINFOID:0000000003771862
Harness or connectors
(The ECM to the TCM circuit is open or shorted.)
DTC Confirmation ProcedureINFOID:0000000003771863
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 proc edure to confirm the malfunction is eliminated.
WITH CONSULT-III
1. Turn ignition switch “ON” and select “DATA MO NITOR” mode for “TRANSMISSION” with CONSULT-III.
2. Start engine and maintain the following conditions for at least 10 consecutive seconds. VHCL/S SE-A/T: 10 km/h (6 MPH) or more
ACCELE POSI: More than 1/8
SLCT LVR POSI: “D” position
3. If DTC is detected, go to TM-52, "Diagnosis Procedure"
.
Diagnosis ProcedureINFOID:0000000003771864
1.CHECK CAN COMMUNICATION LINE
Perform the self-diagnosis. Refer to TM-32, "CONSULT-III Function (TRANSMISSION)"
.
Is a malfunction in the CAN communication indicated in the results?
YES >> Check CAN communication line. Refer to TM-39.
NO >> GO TO 2.
2.CHECK DTC WITH TCM
With CONSULT-III
1. Start engine.
2. Select “ECU INPUT SIGNALS” in “DATA MONI TOR” mode for “TRANSMISSION” with CONSULT-III.
3. While monitoring engine speed, check for engine speed change corresponding to wide-open throttle posi-
tion signal.
OK or NG
OK >> GO TO 3.
Item name Condition Display value (rpm)
ENGINE SPEED Engine running Closely matches the tachometer reading.
Item name Condition Display value (rpm)
ENGINE SPEED Engine running Closel y matches the tachometer reading.
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TM-64
< COMPONENT DIAGNOSIS >
P0740 TORQUE CONVERTER
P0740 TORQUE CONVERTER
DescriptionINFOID:0000000003771890
 The torque converter clutch solenoid valve is activated, with the gear in D4, D5 by the TCM in response to
signals sent from the vehicle speed sensor and accelera tor pedal position sensor (throttle position sensor).
Torque converter clutch piston operation will then be controlled.
 Lock-up operation, however, is prohibited when A/T fluid temperature is too low.
 When the accelerator pedal is depressed (less than 1/8) in lock-up condition, the engine speed should not
change abruptly. If there is a big jump in engine speed, there is no lock-up.
CONSULT-III Reference Value in Data Monitor ModeINFOID:0000000003771891
On Board Diagnosis LogicINFOID:0000000003771892
 This is an OBD-II self-diagnostic item.
 Diagnostic trouble code “P0740” with CONSULT-III is detected under the following conditions.
- When TCM detects an improper voltage drop when it tries to operate the solenoid valve.
- When TCM detects as irregular by comparing target value with monitor value.
Possible CauseINFOID:0000000003771893
 Torque converter clutch solenoid valve
 Harness or connectors (The solenoid circuit is open or shorted.)
DTC Confirmation ProcedureINFOID:0000000003771894
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 proc edure to confirm the malfunction is eliminated.
WITH CONSULT-III
1. Turn ignition switch “ON”. (Do not start engine.)
2. Select “DATA MONITOR” mode for “ENGINE” with CONSULT-III.
3. Start engine and maintain the following conditions for at least 5 consecutive seconds.
VHCL/S SE-A/T: 80 km/h (50 MPH) or more
ACCELE POSI: 0.5/8 - 1.0/8
SLCT LVR POSI: “D” position
Driving location: Driving the vehicle uphill (increased engine load) will help maintain the driving
conditions required for this test.
4. If DTC is detected go to TM-64, "Diagnosis Procedure"
.
WITH GST
Follow the procedure “With CONSULT-III”.
Diagnosis ProcedureINFOID:0000000003771895
1.CHECK INPUT SIGNAL
With CONSULT-III
1. Turn ignition switch “ON”.
2. Select “MAIN SIGNALS” in “DATA MONITO R” mode for “TRANSMISSION” with CONSULT-III.
3. Start engine.
Item name Condition Display value (Approx.)
TCC SOLENOID When performing slip lock-up 0.2 - 0.4 A
When performing lock-up 0.4 - 0.6 A
Revision: December 20092009 QX56

TM-68
< COMPONENT DIAGNOSIS >
P0745 PRESSURE CONTROL SOLENOID A
P0745 PRESSURE CONTROL SOLENOID A
DescriptionINFOID:0000000003771902
The line pressure solenoid valve regulates the oil pump discharge pressure to suit the driving condition in
response to a signal sent from the TCM.
The line pressure duty cycle value is not consistent when the closed throttle position signal is “ON”.
To confirm the line pressure duty cycle at low pressu re, the accelerator (throttle) should be open until
the closed throttle posi tion signal is “OFF”.
CONSULT-III Reference Value in Data Monitor ModeINFOID:0000000003771903
On Board Diagnosis LogicINFOID:0000000003771904
 This is an OBD-II self-diagnostic item.
 Diagnostic trouble code “P0745” with CONSULT-III is detected under the following conditions.
- When TCM detects an improper voltage drop when it tries to operate the solenoid valve.
- When TCM detects as irregular by comparing target value with monitor value.
Possible CauseINFOID:0000000003771905
 Harness or connectors
(The solenoid circuit is open or shorted.)
 Line pressure solenoid valve
DTC Confirmation ProcedureINFOID:0000000003771906
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 proc edure to confirm the malfunction is eliminated.
WITH CONSULT-III
1. Turn ignition switch “ON” and select “DATA MONITOR” mode for “ENGINE” with CONSULT-III.
2. Engine start and wait at least 5 second.
3. If DTC is detected, go to TM-68, "Diagnosis Procedure"
.
WITH GST
Follow the procedure “With CONSULT-III”.
Diagnosis ProcedureINFOID:0000000003771907
1.CHECK INPUT SIGNAL
With CONSULT-III
1. Turn ignition switch “ON”.
2. Select “MAIN SIGNALS” in “DATA MONITO R” mode for “TRANSMISSION” with CONSULT-III.
3. Start the engine.
4. Read out the value of “LINE PRES SOL” while driving.
OK or NG
OK >> GO TO 4.
NG >> GO TO 2.
2.CHECK TCM POWER SUPPLY AND GROUND CIRCUIT
Item name Condition Display value (Approx.)
LINE PRES SOL During driving 0.2 - 0.6 A
Item name Condition Display value (Approx.)
LINE PRES SOL During driving 0.2 - 0.6 A
Revision: December 20092009 QX56