2008 INFINITI QX56 ECU

TM-3
CEF
G H
I
J
K L
M A
B
TM
N
O P
P1752 INPUT CLUTCH SOLENOID .............. ....80
Description .......................................................... ....80
CONSULT-III Reference Value in Data Monitor
Mode ................................................................... ....
80
On Board Diagnosis Logic ......................................80
Possible Cause .......................................................80
DTC Confirmation Procedure ..................................80
Diagnosis Procedure ...............................................80
P1757 FRONT BRAKE SOLENOID ...................82
Description .......................................................... ....82
CONSULT-III Reference Value in Data Monitor
Mode ................................................................... ....
82
On Board Diagnosis Logic ......................................82
Possible Cause .......................................................82
DTC Confirmation Procedure ..................................82
Diagnosis Procedure ...............................................82
P1762 DIRECT CLUTCH SOLENOID ................84
Description .......................................................... ....84
CONSULT-III Reference Value in Data Monitor
Mode ................................................................... ....
84
On Board Diagnosis Logic ......................................84
Possible Cause .......................................................84
DTC Confirmation Procedure ..................................84
Diagnosis Procedure ...............................................84
P1767 HIGH AND LOW REVERSE CLUTCH
SOLENOID .........................................................
86
Description .......................................................... ....86
CONSULT-III Reference Value in Data Monitor
Mode ................................................................... ....
86
On Board Diagnosis Logic ......................................86
Possible Cause .......................................................86
DTC Confirmation Procedure ..................................86
Diagnosis Procedure ...............................................86
P1772 LOW COAST BRAKE SOLENOID .........88
Description .......................................................... ....88
CONSULT-III Reference Value in Data Monitor
Mode ................................................................... ....
88
On Board Diagnosis Logic ......................................88
Possible Cause .......................................................88
DTC Confirmation Procedure ..................................88
Diagnosis Procedure ...............................................88
P1774 LOW COAST BRAKE SOLENOID .........90
Description .......................................................... ....90
CONSULT-III Reference Value in Data Monitor
Mode ................................................................... ....
90
On Board Diagnosis Logic ......................................90
Possible Cause .......................................................90
DTC Confirmation Procedure ..................................90
Diagnosis Procedure ...............................................90
MAIN POWER SUPPLY AND GROUND CIR-
CUIT ....................................................................
92
Diagnosis Procedure ........................................... ....92
CLOSED THROTTLE POSITION AND WIDE
OPEN THROTTLE POSITION CIRCUIT ...........
94
CONSULT-III Reference Value in Data Monitor
Mode .................................................................... ....
94
Diagnosis Procedure ...............................................94
BRAKE SIGNAL CIRCUIT ................................95
CONSULT-III Reference Va lue in Data Monitor
Mode .................................................................... ....
95
Diagnosis Procedure ...............................................95
TOW MODE SWITCH .......................................96
Description ...............................................................96
Diagnosis Procedure ...............................................96
A/T SHIFT LOCK SYSTEM ...............................97
Wiring Diagram - A/T Shift Lock System .................97
Terminals And Reference Values ..........................100
Component Description ....................................... ..100
ECU DIAGNOSIS .......................................103
TCM .................................................................103
Reference Value .................................................. ..103
Wiring Diagram — A/T CONTROL SYSTEM — .. ..105
Fail-Safe .............................................................. ..114
DTC Inspection Priority Chart ................................116
DTC No. Index .......................................................116
DTC Alphabetical Index .........................................117
SYMPTOM DIAGNOSIS ............................118
SYSTEM SYMPTOM .......................................118
A/T Check Indicator Lamp Does Not Come On ... ..118
Engine Cannot Be Started in "P" or "N" Position ...118
In "P" Position, Vehicle Moves When Pushed .......119
In "N" Position, Vehicle Moves ..............................119
Large Shock("N" to "D" Position) ...........................121
Vehicle Does Not Creep Backward in "R" Position ..123
Vehicle Does Not Creep Forward in "D" Position ..125
Vehicle Cannot Be Started from D1 ......................128
A/T Does Not Shift: D1→D2 ..................................130
A/T Does Not Shift: D2→ D3 ..................................131
A/T Does Not Shift: D3→ D4 ..................................133
A/T Does Not Shift: D4→ D5 ..................................135
A/T Does Not Perform Lock-up ........................... ..137
A/T Does Not Hold Lock-up Condition ...................139
Lock-up Is Not Released .......................................140
Engine Speed Does Not Return to Idle .................141
A/T Does Not Shift: 5GR → 4GR ........................ ..142
A/T Does Not Shift: 4GR → 3GR ........................ ..144
A/T Does Not Shift: 3GR → 2GR ........................ ..146
A/T Does Not Shift: 2GR → 1GR ........................ ..147
Vehicle Does Not Decelerate By Engine Brake ... ..149
Symptom Table .....................................................151
PRECAUTION ............................................173
PRECAUTIONS ...............................................173
Revision: March 2010 2008 QX56

TM-32
< FUNCTION DIAGNOSIS >
DIAGNOSIS SYSTEM (TCM)
DIAGNOSIS SYSTEM (TCM)
CONSULT-III Function (TRANSMISSION)INFOID:0000000001604007
CONSULT-III can display each diagnostic item us ing the diagnostic test modes shown following.
SELF-DIAGNOSTIC RESULT MODE
Operation Procedure
After performing SELF-DIAGNOSTIC RESULT MO DE, place check marks for results on the TM-6, "Diagnostic
Work Sheet". Reference pages are provided following the items.
Display Items List
X: Applicable, —: Not applicable
TCM diagnostic mode Description
WORK SUPPORT Supports 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-III instead of a technici an to determine whether each system is “OK” or “NG”.
ECU PART NUMBER TCM part number can be read.
Items (CONSULT-III screen terms) Malfunction is detected when... TCM self-di-
agnosis OBD-II (DTC)
Reference page
“TRANSMIS-
SION” with
CONSULT-III MIL indicator
lamp*1, “EN-
GINE” with
CONSULT-III or GST
CAN COMM CIRCUIT • When a malfunction is detected in CAN communica-
tions U1000 U1000
TM-38
STARTER RELAY• If this signal is ON other than in P or N position, this is
judged to be a malfunction.
(And if it is OFF in P or N position, this too is judged to
be a malfunction.) P0615
—TM-39
TRANSMISSION
CONT • TCM is malfunctioning.
P0700 P0700TM-42
T/M RANGE SWITCH A• PNP switch 1-4 signals input with impossible pattern
• “P” position is detected from N position without any
other position being detected in between. P0705 P0705
TM-43
INPUT SPEED SEN-
SOR A• TCM does not receive the proper voltage signal from
the sensor.
• TCM detects an irregularity only at position of 4th gear
for turbine revolution sensor 2. P0717 P0717
TM-46
OUTPUT SPEED SEN-
SOR• Signal from vehicle speed sensor A/T (Revolution sen-
sor) not input due to cut line or the like
• Unexpected signal input during running
• After ignition switch is turned ON, unexpected signal
input from vehicle speed sensor MTR before the vehi-
cle starts moving P0720 P0720
TM-49
ENGINE SPEED• TCM does not receive the CAN communication signal
from the ECM. P0725
—TM-51
1GR INCORRECT RA-
TIO • A/T cannot shift to 1st gear
P0731 P0731TM-54
Revision: March 2010 2008 QX56

TM-34
< FUNCTION DIAGNOSIS >
DIAGNOSIS SYSTEM (TCM)
*1: Refer to EC-55, "Malfunction Indicator Lamp (MIL)".
*2:These malfunctions cannot be displayed MIL if another malfunction is assigned to MIL.
DATA MONITOR MODE
Display Items List
X: Standard, —: Not applicable
LC/B SOLENOID FNCT • TCM detects an improper voltage drop when it tries to
operate the solenoid valve.
• Condition of ATF pressure switch 2 is different from
monitor value, and relation between gear position and
actual gear ratio is irregular. P1774 P1774*2
TM-90
NO DTC IS DETECTED
FURTHER TESTING
MAY BE REQUIRED• No NG item has been detected.
XX
Items (CONSULT-III
screen terms) Malfunction is detected when... TCM self-di-
agnosis OBD-II (DTC)
Reference page
“TRANSMIS-
SION” with
CONSULT-III MIL indicator
lamp*1, “EN-
GINE” with
CONSULT-III or
GST
Monitored item (Unit) Monitor Item Selection
Remarks
ECU IN-
PUT SIG-
NALS MAIN SIG-
NALS SELEC-
TION
FROM
MENU
VHCL/S SE·A/T (km/h) XXX Output speed sensor
VHCL/S SE·MTR (km/h) X— X
ACCELE POSI (0.0/8) X— X Accelerator pedal position signal
THROTTLE POSI (0.0/8) XXXDegree of opening for accelerator recognized by
the TCM
For fail-safe operation, the specific value used
for control is displayed.
CLSD THL POS (ON-OFF display) X— X
Signal input with CAN communications
W/O THL POS (ON-OFF display) X— X
BRAKE SW (ON-OFF display) X— X Stop lamp switch
GEAR —XXGear position recognized by the TCM updated
after gear-shifting
ENGINE SPEED (rpm) XXX
INPUT SPEED (rpm) XXX
OUTPUT REV (rpm) XXX
GEAR RATIO —XX
TC SLIP SPEED (rpm) —XXDifference between engine speed and torque
converter input shaft speed
F SUN GR REV (rpm) —— X
F CARR GR REV (rpm) —— X
ATF TEMP SE 1 (V) X— X
ATF TEMP SE 2 (V) X— X
ATF TEMP 1 (° C) —XX
ATF TEMP 2 (° C) —XX
BATTERY VOLT (V) X— X
ATF PRES SW 1 (ON-OFF display) XXX Not mounted but displayed.
Revision: March 2010 2008 QX56

DIAGNOSIS SYSTEM (TCM)TM-35
< FUNCTION DIAGNOSIS >
CEF
G H
I
J
K L
M A
B
TM
N
O P
ATF PRES SW 2 (ON-OFF display) XX X (for LC/B solenoid)
ATF PRES SW 3 (ON-OFF display) XX X
Not mounted but displayed.
ATF PRES SW 5 (ON-OFF display) XX X
ATF PRES SW 6 (ON-OFF display) XX X
RANGE SW 1 (ON-OFF display) X— X
RANGE SW 2 (ON-OFF display) X— X
RANGE SW 3 (ON-OFF display) X— X
RANGE SW 4 (ON-OFF display) X— X
SLCT LVR POSI —XXSelector lever position is recognized by the TCM.
For fail-safe operation, the specific value used
for control is displayed.
1 POSITION SW (ON-OFF display) X— X 1st position switch
OD CONT SW (ON-OFF display) X— X 4th position switch
POWERSHIFT SW (ON-OFF display) X —X
Not mounted but displayed.
HOLD SW (ON-OFF display)
X— X
MANU MODE SW (ON-OFF display) X— X
NON M-MODE SW (ON-OFF display) X —X
UP SW LEVER (ON-OFF display) X— X
DOWN SW LEVER (ON-OFF display) X —X
SFT UP ST SW (ON-OFF display) —— X
SFT DWN ST SW (ON-OFF display) — —X
ASCD-OD CUT (ON-OFF display) —— X
ASCD-CRUISE (ON-OFF display) —— X
ABS SIGNAL (ON-OFF display) —— X
ACC OD CUT (ON-OFF display) —— X
ICC (Intelligent cruise control)
ACC SIGNAL (ON-OFF display) —— X
TCS GR/P KEEP (ON-OFF display) —— X
TCS SIGNAL 2 (ON-OFF display) —— X
TCS SIGNAL 1 (ON-OFF display) —— X
TCC SOLENOID (A) —XX
LINE PRES SOL (A) —XX
I/C SOLENOID (A) —XX
FR/B SOLENOID (A) —XX
D/C SOLENOID (A) —XX
HLR/C SOL (A) —XX
ON OFF SOL (ON-OFF display) —— X LC/B solenoid
TCC SOL MON (A) —— X
L/P SOL MON (A) —— X
I/C SOL MON (A) —— X
FR/B SOL MON (A) —— X
D/C SOL MON (A) —— X
HLR/C SOL MON (A) —— X
Monitored item (Unit)
Monitor Item Selection
Remarks
ECU IN-
PUT SIG- NALS MAIN SIG-
NALS SELEC-
TION
FROM
MENU
Revision: March 2010 2008 QX56

TM-36
< FUNCTION DIAGNOSIS >
DIAGNOSIS SYSTEM (TCM)
ONOFF SOL MON (ON-OFF display) ——X LC/B solenoid
P POSI IND (ON-OFF display) —— X
R POSI IND (ON-OFF display) —— X
N POSI IND (ON-OFF display) —— X
D POSI IND (ON-OFF display) —— X
4TH POSI IND (ON-OFF display) —— X
3RD POSI IND (ON-OFF display) —— X
2ND POSI IND (ON-OFF display) —— X
1ST POSI IND (ON-OFF display) —— X
MANU MODE IND (ON-OFF display) — —X
Not mounted but displayed.
POWER M LAMP (ON-OFF display) —— X
F-SAFE IND/L (ON-OFF display) —— X
ATF WARN LAMP (ON-OFF display) — —X
BACK-UP LAMP (ON-OFF display) —— X
STARTER RELAY (ON-OFF display) — —X
RANGE SW3 MON (ON-OFF display) — —X
C/V CLB ID1 —— X
C/V CLB ID2 —— X
C/V CLB ID3 —— X
UNIT CLB ID1 —— X
UNIT CLB ID2 —— X
UNIT CLB ID3 —— X
TRGT GR RATIO —— X
TRGT PRES TCC (kPa) —— X
TRGT PRES L/P (kPa) —— X
TRGT PRES I/C (kPa) —— X
TRGT PRE FR/B (kPa) —— X
TRGT PRES D/C (kPa) —— X
TRG PRE HLR/C (kPa) —— X
SHIFT PATTERN —— X
DRV CST JUDGE —— X
START RLY MON —— X
NEXT GR POSI —— X
SHIFT MODE —— X
MANU GR POSI —— X
VEHICLE SPEED (km/h) —XX Vehicle speed recognized by the TCM.
Voltage (V) —— XDisplays the value measured by the voltage
probe.
Monitored item (Unit)
Monitor Item Selection
Remarks
ECU IN-
PUT SIG- NALS MAIN SIG-
NALS SELEC-
TION
FROM
MENU
Revision: March 2010 2008 QX56

DIAGNOSIS SYSTEM (TCM)TM-37
< FUNCTION DIAGNOSIS >
CEF
G H
I
J
K L
M A
B
TM
N
O P
DTC WORK SUPPORT MODE
Display Items List
Frequency (Hz) —— X
The value measured by the pulse probe is dis-
played.
DUTY-HI (high) (%)
—— X
DUTY-LOW (low) (%) —— X
PLS WIDTH-HI (ms) —— X
PLS WIDTH-LOW (ms) —— X
Monitored item (Unit)
Monitor Item Selection
Remarks
ECU IN-
PUT SIG- NALS MAIN SIG-
NALS SELEC-
TION
FROM
MENU
DTC work support item DescriptionCheck 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: March 2010 2008 QX56

P0615 STARTER RELAYTM-39
< COMPONENT DIAGNOSIS >
CEF
G H
I
J
K L
M A
B
TM
N
O P
P0615 STARTER RELAY
DescriptionINFOID:0000000001604014
• TCM prohibits cranking other than at “P” or “N” position.
CONSULT-III Reference Val ue in Data Monitor ModeINFOID:0000000001604015
On Board Diagnosis LogicINFOID:0000000001604016
• This is not an OBD-II self-diagnostic item.
• Diagnostic trouble code “P0615” with CONSULT-III is det ected when starter relay is switched “ON” other
than at “P” or “N” position. (Or when s witched “OFF” at “P” or “N” position).
Possible CauseINFOID:0000000001604017
• Harness or connectors
The starter relay and TCM circuit is open or shorted.
•Starter relay
DTC Confirmation ProcedureINFOID:0000000001604018
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. Start engine.
4. Drive vehicle for at least 2 consecutive seconds.
5. If DTC is detected, go to TM-39, "
Diagnosis Procedure".
Diagnosis ProcedureINFOID:0000000001604020
1.CHECK STARTER RELAY
With CONSULT-III
1. Turn ignition switch “ON”. (Do not start engine.)
2. Select “SELECTION FROM MENU” in “DATA MONI TOR” mode for “TRANSMISSION” with CONSULT-III
and check monitor “STARTER RELAY” ON/OFF.
Without CONSULT-III
Item name Condition Display value
STARTER RELAY Selector lever in
“N”,“P” position. ON
Selector lever in other position. OFF
Item nameCondition Display value
STARTER RELAY Selector lever in "N
'', "P'' positions. ON
Selector lever in other positions. OFF
Revision: March 2010 2008 QX56

TM-42
< COMPONENT DIAGNOSIS >
P0700 TRANSMISSION CONTROL
P0700 TRANSMISSION CONTROL
DescriptionINFOID:0000000001604021
The TCM consists of a microcomputer and connectors for signal input and output and for power supply. The
TCM controls the A/T.
On Board Diagn osis LogicINFOID:0000000001604022
• This is an OBD-II self-diagnostic item.
• Diagnostic trouble code “P0700” with CONSULT-III is detected when the TCM is malfunctioning.
Possible CauseINFOID:0000000001604023
TCM.
DTC Confirmation ProcedureINFOID:0000000001604024
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 “TRANSMISSION” with CONSULT-III.
3. Start engine.
4. Run engine for at least 2 consecutive seconds at idle speed.
5. If DTC is detected, go to TM-42, "
Diagnosis Procedure".
WITH GST
Follow the procedure “With CONSULT-III”.
Diagnosis ProcedureINFOID:0000000001604025
1.CHECK DTC
With CONSULT-III
1. Turn ignition switch “ON”. (Do not start engine.)
2. Select “SELF DIAG RESULTS” mode for “TRANSMISSION” with CONSULT-III.
3. Touch “ERASE”.
4. Turn ignition switch “OFF” and wait at least 10 seconds.
5. Perform DTC Confirmation Procedure, TM-42, "
DTC Confirmation Procedure".
Is the
“P0700” displayed again?
YES >> Replace the control valve with TCM. Refer to TM-201, "Control Valve with TCM and A/T Fluid
Temperature Sensor 2".
NO >> INSPECTION END
Revision: March 2010 2008 QX56