INFINITI QX56 2008 Factory Service Manual
Page 3631 of 4083
TM-84
< COMPONENT DIAGNOSIS >
P1762 DIRECT CLUTCH SOLENOID
P1762 DIRECT CLUTCH SOLENOID
DescriptionINFOID:0000000001604136
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:0000000001604137
On Board Diagn osis LogicINFOID:0000000001604138
• 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:0000000001604139
• Harness or connectors (The solenoid circuit is open or shorted.)
• Direct clutch solenoid valve
DTC Confirmation ProcedureINFOID:0000000001604140
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 POS: 1.5/8 - 2.0/8
Selector lever: “D” position
Gear position: 1st ⇒ 2GR (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:0000000001604141
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: March 2010 2008 QX56
Page 3632 of 4083
P1762 DIRECT CLUTCH SOLENOIDTM-85
< 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-201, "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-84, "
DTC Confirmation Procedure".
OK or NG
OK >> INSPECTION END
NG >> GO TO 2.
Item name Condition Display value (Ap-
prox.)
D/C SOLE-
NOID Direct clutch disengaged. Refer to
TM-9
0.6 - 0.8 A
Direct clutch engaged. Refer to TM-9
0 - 0.05 A
Revision: March 2010 2008 QX56
Page 3633 of 4083
TM-86
< COMPONENT DIAGNOSIS >
P1767 HIGH AND LOW REVERSE CLUTCH SOLENOID
P1767 HIGH AND LOW REVERSE CLUTCH SOLENOID
DescriptionINFOID:0000000001604142
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:0000000001604143
On Board Diagn osis LogicINFOID:0000000001604144
• 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:0000000001604145
• Harness or connectors
(The solenoid circuit is open or shorted.)
• High and low reverse clutch solenoid valve
DTC Confirmation ProcedureINFOID:0000000001604146
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 POS: 1.5/8 - 2.0/8
Selector lever: “D” position
Gear position: 2nd ⇒ 3GR (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:0000000001604147
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: March 2010 2008 QX56
Page 3634 of 4083
P1767 HIGH AND LOW REVERSE CLUTCH SOLENOID
TM-87
< COMPONENT DIAGNOSIS >
C EF
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-201, "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-86, "
DTC Confirmation Procedure".
OK or NG
OK >> INSPECTION END
NG >> GO TO 2.
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: March 2010 2008 QX56
Page 3635 of 4083
TM-88
< COMPONENT DIAGNOSIS >
P1772 LOW COAST BRAKE SOLENOID
P1772 LOW COAST BRAKE SOLENOID
DescriptionINFOID:0000000001604148
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.
CONSULT-III Reference Value in Data Monitor ModeINFOID:0000000001604149
On Board Diagn osis LogicINFOID:0000000001604150
• 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:0000000001604151
• Harness or connectors(The solenoid circuit is open or shorted.)
• Low coast brake solenoid valve
DTC Confirmation ProcedureINFOID:0000000001604152
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.
Selector lever: “1” or “2”
Gear position: “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:0000000001604153
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 SOL Low coast brake engaged. Refer to TM-9
ON
Low coast brake disengaged. Refer to TM-9
OFF
Revision: March 2010 2008 QX56
Page 3636 of 4083
P1772 LOW COAST BRAKE SOLENOIDTM-89
< COMPONENT DIAGNOSIS >
CEF
G H
I
J
K L
M A
B
TM
N
O P
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-201, "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-88, "
DTC Confirmation Procedure".
OK or NG
OK >> INSPECTION END
NG >> GO TO 2.
Revision: March 2010 2008 QX56
Page 3637 of 4083
TM-90
< COMPONENT DIAGNOSIS >
P1774 LOW COAST BRAKE SOLENOID
P1774 LOW COAST BRAKE SOLENOID
DescriptionINFOID:0000000001604154
• 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 (circuits 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:0000000001604155
On Board Diagn osis LogicINFOID:0000000001604156
• 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 irregular, 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:0000000001604157
• Harness or connectors
(The solenoid and switch circuits are open or shorted.)
• Low coast brake solenoid valve
• ATF pressure switch 2
DTC Confirmation ProcedureINFOID:0000000001604158
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.
Selector lever: “1” or “2” position
Gear position: “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 “TRANSMISSION” 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:0000000001604159
1.CHECK INPUT SIGNALS
Item nameCondition 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: March 2010 2008 QX56
Page 3638 of 4083
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-201, "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: March 2010 2008 QX56
Page 3639 of 4083
TM-92
< COMPONENT DIAGNOSIS >
MAIN POWER SUPPLY AND GROUND CIRCUIT
MAIN POWER SUPPLY AND GROUND CIRCUIT
Diagnosis ProcedureINFOID:0000000001604160
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, 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 TerminalVoltage
TCM F91 - Ground
Battery voltage
2 - Ground
6 - Ground 0V
SCIA2104E
ItemConnector TerminalVoltage
TCM F91 - Ground
Battery voltage
2 - Ground
6 - Ground
SCIA2105E
Continuity should exist.
SCIA2106E
Revision: March 2010 2008 QX56
Page 3640 of 4083
MAIN POWER SUPPLY AND GROUND CIRCUITTM-93
< COMPONENT DIAGNOSIS >
CEF
G H
I
J
K L
M A
B
TM
N
O P
5.DETECT MALFUNCTIONING ITEM
Check the following items:
• The A/T assembly harness connector terminals for damage or loose connection with harness connector.
OK or NG
OK >> GO TO 6.
NG >> Repair or replace damaged parts.
6.PERFORM SELF-DIAGNOSIS
Perform self-diagnosis. Refer to TM-32, "
CONSULT-III Function (TRANSMISSION)".
OK or NG
OK >> INSPECTION END
NG-1 >> Self-diagnosis does not activate: GO TO 7.
NG-2 >> DTC is displayed: Check t he malfunctioning system. Refer to TM-32, "
CONSULT-III Function
(TRANSMISSION)".
7.CHECK TERMINAL CORD ASSEMBLY
1. Remove control valve with TCM. Refer to TM-201, "
Control Valve with TCM and A/T Fluid Temperature
Sensor 2".
2. Disconnect A/T assembly harness connector and TCM connector.
3. Check continuity between A/T assembly harness connector ter- minals and TCM connector terminals.
4. Check continuity between A/T assembly harness connector ter- minals and TCM connector terminals.
5. If OK, check harness for short to ground and short to power.
OK or NG
OK >> Replace the control valve with TCM. Refer to TM-201, "Control Valve with TCM and A/T Fluid
Temperature Sensor 2".
NG >> Replace open circuit or short to ground and short to power in harness or connectors.
Item Connector Terminal Continuity
A/T assembly harness con-
nector F9
1
Ye s
TCM connector F5029
A/T assembly harness con-
nector F9
2
Ye s
TCM connector F50210
A/T assembly harness con-
nector F9
6
Ye s
TCM connector F5024
SCIA5464E
Item Connector Terminal Continuity
A/T assembly harness con-
nector F9
5
Ye s
TCM connector F50421
A/T assembly harness con-
nector F9
10
Ye s
TCM connector F50422
SCIA5465E
Revision: March 2010 2008 QX56