check engine INFINITI QX56 2006 Factory Workshop Manual

AT-146
DTC P1759 FRONT BRAKE SOLENOID VALVE FUNCTION
Revision: November 20092006 QX56
Diagnostic ProcedureECS00CI4
1. CHECK INPUT SIGNALS
With CONSULT-II
1. Start engine.
2. Select “SELECTION FROM MENU ” in “DATA MONITOR” mode
for “A/T ” with CONSULT-II.
3. Drive vehicle in the “D ” position (3rd
4th gear), and confirm
the ON/OFF actuation of the “ATF PRES SW 1 ” and electrical
current value of “FR/B SOLENOID ”.
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 AT- 1 6 7 , "
MAIN POWER SUPPLY AND GROUND CIR-
CUIT" .
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 connec-
tor.
OK or NG
OK >> Replace the control valve with TCM. Refer to AT- 2 3 0 , "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 AT- 1 4 5 , "DTC Confirmation Procedure" .
OK or NG
OK >> INSPECTION END
NG >> GO TO 2.
Item name Condition Display value
(Approx.)
FR/B SOLE-
NOID Front brake engaged. Refer to
AT- 2 0
. 0.6 - 0.8 A
Front brake disengaged. Refer to AT- 2 0
. 0 - 0.05 A
ATF PRES
SW 1 Front brake engaged. Refer to
AT- 2 0
.ON
Front brake disengaged. Refer to AT- 2 0
.OFF
SCIA4796E

AT-148
DTC P1762 DIRECT CLUTCH SOLENOID VALVE
Revision: November 20092006 QX56
Diagnostic ProcedureECS00CIA
1. CHECK INPUT SIGNAL
With CONSULT-II
1. Turn ignition switch “ ON”.
2. Select “MAIN SIGNALS” in “DATA MONITOR” mode for “A/T”
with CONSULT-II.
3. Start the engine.
4. Read out the value of “D/C SOLENOID” while driving.
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 AT- 1 6 7 , "
MAIN POWER SUPPLY AND GROUND CIR-
CUIT" .
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 connec-
tor.
OK or NG
OK >> Replace the control valve with TCM. Refer to AT- 2 3 0 , "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 AT- 1 4 7 , "DTC Confirmation Procedure" .
OK or NG
OK >> INSPECTION END
NG >> GO TO 2.
Item name Condition Display value
(Approx.)
D/C SOLE-
NOID Direct clutch disengaged. Refer to AT- 2 0
. 0.6 - 0.8 A
Direct clutch engaged. Refer to AT- 2 0
. 0 - 0.05 ASCIA4793E

DTC P1764 DIRECT CLUTCH SOLENOID VALVE FUNCTIONAT-149
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Revision: November 2009 2006 QX56
DTC P1764 DIRECT CLUTCH SOLENOID VALVE FUNCTIONPFP:31940
DescriptionECS00CIB

Direct clutch solenoid valve is controlled by the TCM in response to signals sent from the PNP switch,
vehicle speed sensor and accelerator pedal position sensor (throttle position sensor). 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 mal-
function such as control valve sticking, improper solenoid valve operation.
CONSULT-II Reference ValueECS00CIC
On Board Diagnosis LogicECS00CID

This is an OBD-II self-diagnostic item.

Diagnostic trouble code “P1764 D/C SOLENOID FNCTN ” with CONSULT-II is detected under the follow-
ing conditions.
–When TCM detects that actual gear ratio is irregular, and relation between gear position and condition of
ATF pressure switch 5 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 5 is irregular
during releasing accelerator pedal. (Other than during shift change)
Possible CauseECS00CIE

Harness or connectors
(The solenoid and switch circuits are open or shorted.)

Direct clutch solenoid valve

ATF pressure switch 5
DTC Confirmation ProcedureECS00CIF
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-II
1. Start engine.
2. Accelerate vehicle to maintain the following conditions.
ACCELE POS: 1.5/8 - 2.0/8
Selector lever: “D” position
Gear position: 1st
2nd Gear (D/C ON/OFF)
Driving location: Driving the vehicle uphill (increased
engine load) will help maintain the driving conditions
required for this test.
3. Perform step “2” again.
4. Turn ignition switch “OFF”, then perform step “1” to “3 ” again.
5. Check “SELF-DIAG RESULTS ” mode for “A/T” with CONSULT-
II. If DTC (P1764) is detected, refer to AT- 1 5 0 , "
Diagnostic Procedure" .
If DTC (P1762) is detected, go to AT- 1 4 8 , "
Diagnostic Procedure" .
If DTC (P1845) is detected, go to AT- 1 6 4 , "
Diagnostic Procedure" .
WITH GST
Follow the procedure “With CONSULT-II”.
Item name Condition Display value (Approx.)
D/C SOLENOID Direct clutch disengaged. Refer to
AT- 2 0
.0.6 - 0.8 A
Direct clutch engaged. Refer to AT- 2 0
.0 - 0.05 A
ATF PRES SW 5 Direct clutch engaged. Refer to
AT- 2 0
.ON
Direct clutch disengaged. Refer to AT- 2 0
.OFF
BCIA0030E

AT-150
DTC P1764 DIRECT CLUTCH SOLENOID VALVE FUNCTION
Revision: November 20092006 QX56
Diagnostic ProcedureECS00CIG
1. CHECK INPUT SIGNALS
With CONSULT-II
1. Start the engine.
2. Select “SELECTION FROM MENU ” in “DATA MONITOR” mode
for “A/T ” with CONSULT-II.
3. Drive vehicle in the “D” position (1st
2nd gear), and confirm
the display actuation of the “ATF PRES SW 5 ” and electrical cur-
rent value of “ D/C SOLENOID ”.
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 AT- 1 6 7 , "
MAIN POWER SUPPLY AND GROUND CIR-
CUIT" .
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 connec-
tor.
OK or NG
OK >> Replace the control valve with TCM. Refer to AT- 2 3 0 , "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 AT- 1 4 9 , "DTC Confirmation Procedure" .
OK or NG
OK >> INSPECTION END
NG >> GO TO 2.
Item name Condition Display value
(Approx.)
D/C SOLENOID Direct clutch disengaged. Refer to
AT- 2 0
. 0.6 - 0.8 A
Direct clutch engaged. Refer to AT- 2 0
. 0 - 0.05 A
ATF PRES SW 5 Direct clutch engaged. Refer to AT- 2 0
.ON
Direct clutch disengaged. Refer to AT- 2 0
.OFF
SCIA4797E

AT-152
DTC P1767 HIGH AND LOW REVERSE CLUTCH SOLENOID VALVE
Revision: November 20092006 QX56
Diagnostic ProcedureECS00CIM
1. CHECK INPUT SIGNAL
With CONSULT-II
1. Turn ignition switch “ ON”.
2. Select “MAIN SIGNALS” in “DATA MONITOR” mode for “A/T”
with CONSULT-II.
3. Start the engine.
4. Read out the value of “HLR/C SOLENOID” while driving.
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 AT- 1 6 7 , "
MAIN POWER SUPPLY AND GROUND CIR-
CUIT" .
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 connec-
tor.
OK or NG
OK >> Replace the control valve with TCM. Refer to AT- 2 3 0 , "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 AT- 1 5 1 , "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 AT- 2 0
.
0.6 - 0.8 A
High and low reverse clutch engaged.
Refer to AT- 2 0
. 0 - 0.05 A
SCIA4793E

DTC P1769 HIGH AND LOW REVERSE CLUTCH SOLENOID VALVE FUNCTIONAT-153
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Revision: November 2009 2006 QX56
DTC P1769 HIGH AND LOW REVERSE CLUTCH SOLENOID VALVE FUNCTION
PFP:31940
DescriptionECS00CIN

High and low reverse clutch solenoid valve is controlled by the TCM in response to signals sent from the
PNP switch, vehicle speed sensor and accelerator pedal position sensor (throttle position sensor). 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 mal-
function such as control valve sticking, improper solenoid valve operation.
CONSULT-II Reference ValueECS00CIO
On Board Diagnosis LogicECS00CIP

This is an OBD-II self-diagnostic item.

Diagnostic trouble code “P1769 HLR/C SOL FNCTN ” with CONSULT-II 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 6 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 6 is irregular
during releasing accelerator pedal. (Other than during shift change)
Possible CauseECS00CIQ

Harness or connectors
(The solenoid and switch circuits are open or shorted.)

High and low reverse clutch solenoid valve

ATF pressure switch 6
DTC Confirmation ProcedureECS00CIR
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 procedure to confirm the malfunction is eliminated.
WITH CONSULT-II
1. Start engine.
2. Accelerate vehicle to maintain the following conditions.
ACCELE POS: 1.5/8 - 2.0/8
Selector lever: “D” position
Gear position: 2nd
3rd Gear (HLR/C ON/OFF)
Driving location: Driving the vehicle uphill (increased
engine load) will help maintain the driving conditions
required for this test.
3. Perform step “2” again.
4. Turn ignition switch “OFF”, then perform step “1” to “3 ” again.
5. Check “SELF-DIAG RESULTS ” mode for “A/T” with CONSULT-
II. If DTC (P1769) is detected, refer to AT- 1 5 4 , "
Diagnostic Procedure" .
If DTC (P1767) is detected, go to AT- 1 5 2 , "
Diagnostic Procedure" .
If DTC (P1846) is detected, go to AT- 1 6 6 , "
Diagnostic Procedure" .
Item nameCondition Display value (Approx.)
HLR/C SOL High and low reverse clutch disengaged. Refer to
AT- 2 0
. 0.6 - 0.8 A
High and low reverse clutch engaged. Refer to AT- 2 0
. 0 - 0.05 A
ATF PRES SW 6 High and low reverse clutch engaged. Refer to
AT- 2 0
.ON
High and low reverse clutch disengaged. Refer to AT- 2 0
.OFF
BCIA0030E

AT-154
DTC P1769 HIGH AND LOW REVERSE CLUTCH SOLENOID VALVE FUNCTION
Revision: November 20092006 QX56
Diagnostic ProcedureECS00CIS
1. CHECK INPUT SIGNALS
With CONSULT-II
1. Start the engine.
2. Select “SELECTION FROM MENU ” in “DATA MONITOR” mode
for “A/T ” with CONSULT-II.
3. Drive vehicle in the “D ” position (2nd
3rd gear), and confirm
the ON/OFF actuation of the “ATF PRES SW 6 ” and electrical
current value of “HLR/C 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 AT- 1 6 7 , "
MAIN POWER SUPPLY AND GROUND CIR-
CUIT" .
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 connec-
tor.
OK or NG
OK >> Replace the control valve with TCM. Refer to AT- 2 3 0 , "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 AT- 1 5 3 , "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
AT- 2 0
.
0.6 - 0.8 A
High and low reverse clutch engaged. Refer to AT-
20 . 0 - 0.05 A
ATF PRES
SW 6 High and low reverse clutch engaged. Refer to
AT-
20 . ON
High and low reverse clutch disengaged. Refer to
AT- 2 0
. OFF
SCIA4798E

AT-156
DTC P1772 LOW COAST BRAKE SOLENOID VALVE
Revision: November 20092006 QX56
Diagnostic ProcedureECS00CIY
1. CHECK INPUT SIGNAL
With CONSULT-II
1. Turn ignition switch “ ON”.
2. Select “SELECTION FROM MENU ” in “DATA MONITOR” mode
for “A/T ” with CONSULT-II.
3. Start the engine.
4. Read out the value of “ON OFF SOL” while driving.
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 AT- 1 6 7 , "
MAIN POWER SUPPLY AND GROUND CIR-
CUIT" .
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 connec-
tor.
OK or NG
OK >> Replace the control valve with TCM. Refer to AT- 2 3 0 , "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 AT- 1 5 5 , "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
AT- 2 0
.ON
Low coast brake disengaged. Refer to AT- 2 0
.OFF
SCIA4794E

DTC P1774 LOW COAST BRAKE SOLENOID VALVE FUNCTIONAT-157
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Revision: November 2009 2006 QX56
DTC P1774 LOW COAST BRAKE SOLENOID VALVE FUNCTIONPFP:31940
DescriptionECS00CIZ

Low coast brake solenoid valve is turned “ON” or “OFF ” by the TCM in response to signals sent from the
PNP switch, vehicle speed sensor and accelerator pedal position sensor (throttle position sensor). 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 mal-
function such as control valve sticking, improper solenoid valve operation.
CONSULT-II Reference ValueECS00CJ0
On Board Diagnosis LogicECS00CJ1

This is an OBD-II self-diagnostic item.

Diagnostic trouble code “P1774 LC/B SOLENOID FNCT ” with CONSULT-II 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 CauseECS00CJ2

Harness or connectors
(The solenoid and switch circuits are open or shorted.)

Low coast brake solenoid valve

ATF pressure switch 2
DTC Confirmation ProcedureECS00CJ3
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 procedure to confirm the malfunction is eliminated.
WITH CONSULT-II
1. Start engine.
2. Accelerate vehicle to maintain the following conditions.
Selector lever: “1” or “2” position
Gear position: “1st” or “2nd” gear (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 “A/T” with CONSULT-
II. If DTC (P1774) is detected, refer to AT- 1 5 8 , "
Diagnostic Pro-
cedure" .
If DTC (P1772) is detected, go to AT- 1 5 6 , "
Diagnostic Proce-
dure" .
WITH GST
Follow the procedure “With CONSULT-II”.
Item name Condition Display value
ON OFF SOL Low coast brake engaged. Refer to
AT- 2 0
.ON
Low coast brake disengaged. Refer to AT- 2 0
.OFF
ATF PRES SW 2 Low coast brake engaged. Refer to
AT- 2 0
.ON
Low coast brake disengaged. Refer to AT- 2 0
.OFF
BCIA0030E

AT-158
DTC P1774 LOW COAST BRAKE SOLENOID VALVE FUNCTION
Revision: November 20092006 QX56
Diagnostic ProcedureECS00CJ4
1. CHECK INPUT SIGNALS
With CONSULT-II
1. Start the engine.
2. Select “SELECTION FROM MENU ” in “DATA MONITOR” mode
for “A/T ” with CONSULT-II.
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 AT- 1 6 7 , "
MAIN POWER SUPPLY AND GROUND CIR-
CUIT" .
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 connec-
tor.
OK or NG
OK >> Replace the control valve with TCM. Refer to AT- 2 3 0 , "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 AT- 1 5 7 , "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
AT- 2 0
.ON
Low coast brake disengaged. Refer to AT- 2 0
.OFF
ATF PRES
SW 2 Low coast brake engaged. Refer to
AT- 2 0
.ON
Low coast brake disengaged. Refer to AT- 2 0
.OFF
SCIA4794E