engine INFINITI QX56 2009 Factory Service Manual

P1731 1ST ENGINE BRAKINGTM-79
< COMPONENT DIAGNOSIS >
CEF
G H
I
J
K L
M A
B
TM
N
O P
OK or NG
OK >> GO TO 4.
NG >> GO TO 2.
2.CHECK TCM POWER SUPPLY AND GROUND CIRCUIT
Check TCM power supply and ground circuit. Refer to TM-92, "Diagnosis Procedure"
.
OK or NG
OK >> GO TO 3.
NG >> Repair or replace damaged parts.
3.DETECT MALFUNCTIONING ITEM
Check the following items:
 The A/T assembly harness connector pin terminals for damage or loose connection with harness connector.
OK or NG
OK >> Replace the control valve with TCM. Refer to TM-203, "Control Valve with TCM and A/T Fluid
Temperature Sensor 2".
NG >> Repair or replace damaged parts.
4.CHECK DTC
Perform “DTC Confirmation Procedure”.
 Refer to TM-78, "DTC Confirmation Procedure"
.
OK or NG
OK >> INSPECTION END
NG >> GO TO 2.
ATF PRES
SW 2 Low coast brake engaged. Refer to
TM-9.ON
Low coast brake disengaged. Refer to TM-9
.OFF
Item name Condition Display value
Revision: December 20092009 QX56

TM-80
< COMPONENT DIAGNOSIS >
P1752 INPUT CLUTCH SOLENOID
P1752 INPUT CLUTCH SOLENOID
DescriptionINFOID:0000000003771939
Input clutch solenoid valve is controlled by the TCM in response to signals sent from the transmission range
switch, output speed sensor and accelerator pedal position sensor (throttle position sensor). Gears will then
be shifted to the optimum position.
CONSULT-III Reference Value in Data Monitor ModeINFOID:0000000003771940
On Board Diagn osis LogicINFOID:0000000003771941
 This is an OBD-II self-diagnostic item.
 Diagnostic trouble code “P1752” 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:0000000003771942
 Harness or connectors
(The solenoid circuit is open or shorted.)
 Input clutch solenoid valve
DTC Confirmation ProcedureINFOID:0000000003771943
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 “TRANSMISSION” with CONSULT-III.
3. Start engine.
4. Drive vehicle and maintain the following conditions for at least 5 consecutive seconds.
ACCELE POSI: 1.5/8 - 2.0/8
SLCT LVR POSI: “D” position
GEAR: 3rd ⇒ 4th (I/C ON/OFF)
Driving location: Driving the vehicle uphill (increased engine load) will help maintain the driving
conditions required for this test.
5. If DTC is detected go to TM-80, "Diagnosis Procedure"
.
WITH GST
Follow the procedure “With CONSULT-III”.
Diagnosis ProcedureINFOID:0000000003771944
1.CHECK INPUT SIGNAL
With CONSULT-III
1. Turn ignition switch “ON”.
2. Select “MAIN SIGNALS” in “DATA MONITOR” mode for “TRANMSMISSION” with CONSULT-III.
3. Start the engine.
4. Read out the value of “I/C SOLENOID” while driving.
Item name Condition Display value (Approx.)
I/C SOLENOID Input clutch disengaged. Refer to
TM-9
. 0.6 - 0.8 A
Input clutch engaged. Refer to TM-9
.0 - 0.05 A
Revision: December 20092009 QX56

TM-82
< COMPONENT DIAGNOSIS >
P1757 FRONT BRAKE SOLENOID
P1757 FRONT BRAKE SOLENOID
DescriptionINFOID:0000000003771945
Front brake solenoid valve is controlled by the TCM in response to signals sent from the transmission range
switch, output speed sensor and accelerator pedal position sensor (throttle position sensor). Gears will then
be shifted to the optimum position.
CONSULT-III Reference Value in Data Monitor ModeINFOID:0000000003771946
On Board Diagn osis LogicINFOID:0000000003771947
 This is an OBD-II self-diagnostic item.
 Diagnostic trouble code “P1757” 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:0000000003771948
 Harness or connectors
(The solenoid circuit is open or shorted.)
 Front brake solenoid valve
DTC Confirmation ProcedureINFOID:0000000003771949
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 “TRANSMISSION” with CONSULT-III.
3. Start engine.
4. Drive vehicle and maintain the following conditions for at least 5 consecutive seconds.
ACCELE POSI: 1.5/8 - 2.0/8
SLCT LVR POSI: “D” position
GEAR: 3rd ⇒ 4th (FR/B ON/OFF)
Driving location: Driving the vehicle uphill (increased engine load) will help maintain the driving
conditions required for this test.
5. If DTC is detected go to TM-82, "Diagnosis Procedure"
.
WITH GST
Follow the procedure “With CONSULT-III”.
Diagnosis ProcedureINFOID:0000000003771950
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.
4. Read out the value of “FR/B SOLENOID” while driving.
Item name Condition Display value (Approx.)
FR/B SOLENOID Front brake engaged. Refer to
TM-9
0.6 - 0.8 A
Front brake disengaged. Refer to TM-9
0 - 0.05 A
Revision: December 20092009 QX56

TM-84
< COMPONENT DIAGNOSIS >
P1762 DIRECT CLUTCH SOLENOID
P1762 DIRECT CLUTCH SOLENOID
DescriptionINFOID:0000000003771951
Direct clutch solenoid valve is controlled by the TCM in response to signals sent from the transmission range
switch, output speed sensor and accelerator pedal position sensor (throttle position sensor). Gears will then
be shifted to the optimum position.
CONSULT-III Reference Value in Data Monitor ModeINFOID:0000000003771952
On Board Diagn osis LogicINFOID:0000000003771953
 This is an OBD-II self-diagnostic item.
 Diagnostic trouble code “P1762” 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:0000000003771954
 Harness or connectors
(The solenoid circuit is open or shorted.)
 Direct clutch solenoid valve
DTC Confirmation ProcedureINFOID:0000000003771955
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. Drive vehicle and maintain the following conditions for at least 5 consecutive seconds. ACCELE POSI: 1.5/8 - 2.0/8
SLCT LVR POSI: “D” position
GEAR: 1st ⇒ 2nd (D/C ON/OFF)
Driving location: Driving the vehicle uphill (increased engine load) will help maintain the driving
conditions required for this test.
5. If DTC is detected, go to TM-84, "Diagnosis Procedure"
.
WITH GST
Follow the procedure “With CONSULT-III”.
Diagnosis ProcedureINFOID:0000000003771956
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 “D/C SOLENOID” while driving.
Item name Condition Display value (Approx.)
D/C SOLENOID Direct clutch disengaged. Refer to
TM-9
0.6 - 0.8 A
Direct clutch engaged. Refer to TM-9
0 - 0.05 A
Revision: December 20092009 QX56

TM-86
< COMPONENT DIAGNOSIS >
P1767 HIGH AND LOW REVERSE CLUTCH SOLENOID
P1767 HIGH AND LOW REVERSE CLUTCH SOLENOID
DescriptionINFOID:0000000003771957
High and low reverse clutch solenoid valve is controlled by the TCM in response to signals sent from the trans-
mission range switch, output speed sensor and accelerato r pedal position sensor (throttle position sensor).
Gears will then be shifted to the optimum position.
CONSULT-III Reference Value in Data Monitor ModeINFOID:0000000003771958
On Board Diagn osis LogicINFOID:0000000003771959
 This is an OBD-II self-diagnostic item.
 Diagnostic trouble code “P1767” with CONSULT-III or 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:0000000003771960
 Harness or connectors
(The solenoid circuit is open or shorted.)
 High and low reverse clutch solenoid valve
DTC Confirmation ProcedureINFOID:0000000003771961
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 “TRANSMISSION” with CONSULT-III.
3. Start engine.
4. Drive vehicle and maintain the following conditions for at least 5 consecutive seconds.
ACCELE POSI: 1.5/8 - 2.0/8
SLCT LVR POSI: “D” position
GEAR: 2nd ⇒ 3rd (HLR/C ON/OFF)
Driving location: Driving the vehicle uphill (increased engine load) will help maintain the driving
conditions required for this test.
5. If DTC is detected, go to TM-86, "Diagnosis Procedure"
.
WITH GST
Follow the procedure “With CONSULT-III”.
Diagnosis ProcedureINFOID:0000000003771962
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 “HLR/C SOLENOID” while driving.
Item name Condition Display value (Approx.)
HLR/C SOL High and low reverse clutch disengaged. Refer to
TM-9
0.6 - 0.8 A
High and low reverse clutch engaged. Refer to TM-9
0 - 0.05 A
Revision: December 20092009 QX56

TM-88
< COMPONENT DIAGNOSIS >
P1772 LOW COAST BRAKE SOLENOID
P1772 LOW COAST BRAKE SOLENOID
DescriptionINFOID:0000000003771963
Low coast brake solenoid valve is turned “ON” or “OFF” by the TCM in response to signals sent from the trans-
mission range switch, output speed sensor and accelerato r pedal position sensor (throttle position sensor).
Gears will then be shifted to the optimum position.
CONSULT-III Reference Value in Data Monitor ModeINFOID:0000000003771964
On Board Diagn osis LogicINFOID:0000000003771965
 This is an OBD-II self-diagnostic item.
 Diagnostic trouble code “P1772” with CONSULT-III is detected when TCM detects an improper voltage drop
when it tries to operate the solenoid valve.
Possible CauseINFOID:0000000003771966
 Harness or connectors (The solenoid circuit is open or shorted.)
 Low coast brake solenoid valve
DTC Confirmation ProcedureINFOID:0000000003771967
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.
4. Drive vehicle and maintain the following conditions for at least 5 consecutive seconds.
SLCT LVR POSI: “1” or “2”
GEAR: “1st” or “2nd” (LC/B ON/OFF)
5. If DTC is detected, go to TM-88, "Diagnosis Procedure"
.
WITH GST
Follow the procedure “With CONSULT-III”.
Diagnosis ProcedureINFOID:0000000003771968
1.CHECK INPUT SIGNAL
With CONSULT-III
1. Turn ignition switch “ON”.
2. Select “SELECTION FROM MENU” in “DATA MONI TOR” mode for “TRANSMISSION” with CONSULT-III.
3. Start the engine.
4. Read out the value of “ON OFF SOL” while driving.
OK or NG
OK >> GO TO 4.
Item name Condition Display value
ON OFF SOL Low coast brake engaged. Refer to
TM-9
ON
Low coast brake disengaged. Refer to TM-9
OFF
Item name Condition Display value
ON OFF SOLLow coast brake engaged. Refer to
TM-9
ON
Low coast brake disengaged. Refer to TM-9
OFF
Revision: December 20092009 QX56

TM-90
< COMPONENT DIAGNOSIS >
P1774 LOW COAST BRAKE SOLENOID
P1774 LOW COAST BRAKE SOLENOID
DescriptionINFOID:0000000003771969
 Low coast brake solenoid valve is turned “ON” or “OFF” by the TCM in response to signals sent from the
transmission range switch, output speed sensor and accele rator pedal position sensor (throttle position sen-
sor). Gears will then be shifted to the optimum position.
 This is not only caused by electrical malfunction (cir cuits open or shorted) but also by mechanical malfunc-
tion such as control valve sticking, improper solenoid valve operation.
CONSULT-III Reference Value in Data Monitor ModeINFOID:0000000003771970
On Board Diagn osis LogicINFOID:0000000003771971
 This is an OBD-II self-diagnostic item.
 Diagnostic trouble code “P1774” with CONSULT-III is detected under the following conditions.
- When TCM detects that actual gear ratio is irr egular, and relation between gear position and condition of
ATF pressure switch 2 is irregular during depressing accelerator pedal. (Other than during shift change)
- When TCM detects that relation between gear position and condition of ATF pressure switch 2 is irregular
during releasing accelerator pedal. (Other than during shift change)
Possible CauseINFOID:0000000003771972
 Harness or connectors
(The solenoid and switch circuits are open or shorted.)
 Low coast brake solenoid valve
 ATF pressure switch 2
DTC Confirmation ProcedureINFOID:0000000003771973
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. Start engine.
2. Accelerate vehicle to maintain the following conditions.
SLCT LVR POSI: “1” or “2” position
GEAR: “1st” or “2nd” (LC/B ON/OFF)
3. Perform step “2” again.
4. Turn ignition switch “OFF”, then perform step “1” to “3” again.
5. Check “SELF-DIAG RESULTS” mode for “TRANS MISSION” with CONSULT-III. If DTC (P1774) is
detected, refer to TM-90, "Diagnosis Procedure"
.
If DTC (P1772) is detected, go to TM-88, "Diagnosis Procedure"
.
WITH GST
Follow the procedure “With CONSULT-III”.
Diagnosis ProcedureINFOID:0000000003771974
1.CHECK INPUT SIGNALS
Item name Condition Display value
ON OFF SOLLow coast brake engaged. Refer to
TM-9
ON
Low coast brake disengaged. Refer to TM-9
OFF
ATF PRES SW 2 Low coast brake engaged. Refer to
TM-9
ON
Low coast brake disengaged. Refer to TM-9
OFF
Revision: December 20092009 QX56

P1774 LOW COAST BRAKE SOLENOIDTM-91
< COMPONENT DIAGNOSIS >
CEF
G H
I
J
K L
M A
B
TM
N
O P
With CONSULT-III
1. Start the engine.
2. Select “SELECTION FROM MENU” in “DATA MONI TOR” mode for “TRANSMISSION” with CONSULT-III.
3. Drive vehicle in the “1” or “2” position (“1
1” or “22” gear) and confirm the ON/OFF actuation of the “ATF
PRES SW 2” and “ON OFF SOL”.
OK or NG
OK >> GO TO 4.
NG >> GO TO 2.
2.CHECK TCM POWER SUPPLY AND GROUND CIRCUIT
Check TCM power supply and ground circuit. Refer to TM-92, "Diagnosis Procedure"
.
OK or NG
OK >> GO TO 3.
NG >> Repair or replace damaged parts.
3.DETECT MALFUNCTIONING ITEM
Check the following items:
 The A/T assembly harness connector pin terminals for damage or loose connection with harness connector.
OK or NG
OK >> Replace the control valve with TCM. Refer to TM-203, "Control Valve with TCM and A/T Fluid
Temperature Sensor 2".
NG >> Repair or replace damaged parts.
4.CHECK DTC
Perform “DTC Confirmation Procedure”.
 Refer to TM-90, "DTC Confirmation Procedure"
.
OK or NG
OK >> INSPECTION END
NG >> GO TO 2.
Item name Condition Display value
ON OFF SOL Low coast brake engaged. Refer to
TM-9
ON
Low coast brake disengaged. Refer to TM-9
OFF
ATF PRES
SW 2 Low coast brake engaged. Refer to
TM-9
ON
Low coast brake disengaged. Refer to TM-9
OFF
Revision: December 20092009 QX56

TM-92
< COMPONENT DIAGNOSIS >
MAIN POWER SUPPLY AND GROUND CIRCUIT
MAIN POWER SUPPLY AND GROUND CIRCUIT
Diagnosis ProcedureINFOID:0000000003771975
1.CHECK TCM POWER SOURCE STEP 1
1. Turn ignition switch OFF.
2. Disconnect A/T assembly harness connector.
3. Check voltage between A/T assembly harness connector termi- nals and ground.
OK or NG
OK >> GO TO 2.
NG >> GO TO 3.
2.CHECK TCM POWER SOURCE STEP 2
1. Disconnect A/T assembly harness connector.
2. Turn ignition switch ON. (Do not start engine.)
3. Check voltage between A/T assembly harness connector termi- nals and ground.
OK or NG
OK >> GO TO 4.
NG >> GO TO 3.
3.DETECT MALFUNCTIONING ITEM
Check the following items:
 Harness for short or open between battery and A/T assembly harness connector terminals 1, 2
 Harness for short or open between ignition switch and A/T assembly harness connector terminal 6
 10A fuse [No. 3, 4, located in the fuse block (J /B)] and 10A fuse (No. 49, located in the IPDM E/R)
 Ignition switch
OK or NG
OK >> GO TO 4.
NG >> Repair or replace damaged parts.
4.CHECK TCM GROUND CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect A/T assembly harness connector.
3. Check continuity between A/T assembly harness connector F9 terminals 5, 10 and ground.
If OK, check harness for short to ground and short to power.
OK or NG
OK >> GO TO 5.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
Item Connector Terminal Voltage
TCM F9 1 - Ground
Battery voltage
2 - Ground
6 - Ground 0V
SCIA2104E
Item Connector Terminal Voltage
TCM F9 1 - Ground
Battery voltage
2 - Ground
6 - Ground
SCIA2105E
Continuity should exist.
SCIA2106E
Revision: December 20092009 QX56

TM-94
< COMPONENT DIAGNOSIS >
CLOSED THROTTLE POSITION AND WIDE OPEN THROTTLE POSITION CIR-
CUIT
CLOSED THROTTLE POSITION AND WIDE OPEN THROTTLE POSITION
CIRCUIT
CONSULT-III Reference Value in Data Monitor ModeINFOID:0000000003771976
Diagnosis ProcedureINFOID:0000000003771977
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 THROTTLE POSI TION SIGNAL CIRCUIT
With CONSULT-III
1. Turn ignition switch “ON”. (Do not start engine.)
2. Select “ECU INPUT SIGNALS” in “DATA MONI TOR” mode for “TRANSMISSION” with CONSULT-III.
3. Depress accelerator pedal and read out the value of “CLSD THL POS” and “W/O THL POS”.
OK or NG
OK >> INSPECTION END
NG >> Check the following items. If NG, repair or replace damaged parts.  Perform the self-diagnosis for “ENGINE” with CONSULT-III.
 Open circuit or short to ground or shor t to power in harness or connectors.
 Pin terminals for damage or loos e connection with harness connector.
Item name Condition Display value
CLSD THL POSReleased accelerator pedal. ON
Fully depressed accelerator pedal. OFF
W/O THL POS Fully depressed accelerator pedal. ON
Released accelerator pedal. OFF
Accelerator Pedal Operation Monitor Item
CLSD THL POS W/O THL POS
Released ON OFF
Fully depressed OFF ON
Revision: December 20092009 QX56