ignition INFINITI QX56 2006 Factory Manual PDF

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

DTC P1841 ATF PRESSURE SWITCH 1AT-159
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Revision: November 2009 2006 QX56
DTC P1841 ATF PRESSURE SWITCH 1PFP:25240
DescriptionECS00CJ5
Fail-safe function to detect front brake clutch solenoid valve condition.
CONSULT-II Reference ValueECS00CJ6
On Board Diagnosis LogicECS00CJ7

This is not an OBD-II self-diagnostic item.

Diagnostic trouble code “P1841 ATF PRES SW 1/CIRC ” with CONSULT-II is detected when TCM detects
that actual gear ratio is normal, and relation between gear position and condition of ATF pressure switch 1
is irregular during depressing accelerator pedal. (Other than during shift change)
Possible CauseECS00CJ8

ATF pressure switch 1

Harness or connectors
(The switch circuit is open or shorted.)
DTC Confirmation ProcedureECS00CJ9
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: 3rd
4th Gear (FR/B 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 (P1841) is detected, go to AT- 1 6 0 , "
Diagnostic Procedure" .
If DTC (P1757) is detected, go to AT- 1 4 4 , "
Diagnostic Procedure" .
Item nameCondition Display value
ATF PRES SW 1 Front brake engaged. Refer to
AT- 2 0
.ON
Front brake disengaged. Refer to AT- 2 0
.OFF
BCIA0030E

DTC P1843 ATF PRESSURE SWITCH 3AT-161
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Revision: November 2009 2006 QX56
DTC P1843 ATF PRESSURE SWITCH 3PFP:25240
DescriptionECS00CJB
Fail-safe function to detect input clutch solenoid valve condition.
CONSULT-II Reference ValueECS00CJC
On Board Diagnosis LogicECS00CJD

This is not an OBD-II self-diagnostic item.

Diagnostic trouble code “P1843 ATF PRES SW 3/CIRC ” with CONSULT-II is detected when TCM detects
that actual gear ratio is normal, and relation between gear position and condition of ATF pressure switch 3
is irregular during depressing accelerator pedal. (Other than during shift change)
Possible CauseECS00CJE

ATF pressure switch 3

Harness or connectors
(The switch circuit is open or shorted.)
DTC Confirmation ProcedureECS00CJF
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: 3rd
4th Gear (I/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 (P1843) is detected, go to AT- 1 6 2 , "
Diagnostic Procedure" .
If DTC (P1752) is detected, go to AT- 1 4 0 , "
Diagnostic Procedure" .
Item nameCondition Display value
ATF PRES SW 3 Input clutch engaged. Refer to
AT- 2 0
.ON
Input clutch disengaged. Refer to AT- 2 0
.OFF
BCIA0030E

DTC P1845 ATF PRESSURE SWITCH 5AT-163
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Revision: November 2009 2006 QX56
DTC P1845 ATF PRESSURE SWITCH 5PFP:25240
DescriptionECS00CJH
Fail-safe function to detect direct clutch solenoid valve condition.
CONSULT-II Reference ValueECS00CJI
On Board Diagnosis LogicECS00CJJ

This is not an OBD-II self-diagnostic item.

Diagnostic trouble code “P1845 ATF PRES SW 5/CIRC ” with CONSULT-II is detected when TCM detects
that actual gear ratio is normal, and relation between gear position and condition of ATF pressure switch 5
is irregular during depressing accelerator pedal. (Other than during shift change)
Possible CauseECS00CJK

ATF pressure switch 5

Harness or connectors
(The switch circuit is open or shorted.)
DTC Confirmation ProcedureECS00CJL
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: 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 (P1845) is detected, go to AT- 1 6 4 , "
Diagnostic Procedure" .
If DTC (P1762) is detected, go to AT- 1 4 8 , "
Diagnostic Procedure" .
Item nameCondition Display value
ATF PRES SW 5 Direct clutch engaged. Refer to
AT- 2 0
.ON
Direct clutch disengaged. Refer to AT- 2 0
.OFF
BCIA0030E

DTC P1846 ATF PRESSURE SWITCH 6AT-165
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Revision: November 2009 2006 QX56
DTC P1846 ATF PRESSURE SWITCH 6PFP:25240
DescriptionECS00CJN
Fail-safe function to detect high and low reverse clutch solenoid valve condition.
CONSULT-II Reference ValueECS00CJO
On Board Diagnosis LogicECS00CJP

This is not an OBD-II self-diagnostic item.

Diagnostic trouble code “P1846 ATF PRES SW 6/CIRC ” with CONSULT-II is detected when TCM detects
that actual gear ratio is normal, and relation between gear position and condition of ATF pressure switch 6
is irregular during depressing accelerator pedal. (Other than during shift change)
Possible CauseECS00CJQ

ATF pressure switch 6

Harness or connectors
(The switch circuit is open or shorted.)
DTC Confirmation ProcedureECS00CJR
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 (P1846) is detected, go to AT- 1 6 6 , "
Diagnostic Procedure" .
If DTC (P1767) is detected, go to AT- 1 5 2 , "
Diagnostic Procedure" .
Item nameCondition Display value
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-168
MAIN POWER SUPPLY AND GROUND CIRCUIT
Revision: November 20092006 QX56
TCM terminals and data are reference value. Measured between each terminal and ground.
Diagnostic ProcedureECS00CJU
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.
Terminal Wire
color Item
ConditionData (Approx.)
1P Power supply
(Memory back-up) Always
Battery voltage
2P Power supply
(Memory back-up)
Always
Battery voltage
5 B Ground Always0V
6 Y/R Power supply –
Battery voltage
– 0V
10 B Ground Always0V
ItemConnector TerminalVoltage
TCM F91 - Ground
Battery voltage
2 - Ground
6 - Ground 0V
SCIA2104E
ItemConnector TerminalVoltage
TCM F441 - Ground
Battery voltage
2 - Ground
6 - Ground
SCIA2105E

MAIN POWER SUPPLY AND GROUND CIRCUITAT-169
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Revision: November 2009 2006 QX56
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, Refer to PG-4, "POWER SUPPLY ROUTING CIRCUIT" .
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.
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 AT- 8 6 , "
SELF-DIAGNOSTIC RESULT MODE" .
OK or NG
OK >> INSPECTION END
NG-1 >> Self-diagnosis does not activate: GO TO 7.
NG-2 >> DTC is displayed: Check the malfunctioning system. Refer to AT- 8 6 , "
SELF-DIAGNOSTIC
RESULT MODE" .
Continuity should exist.
SCIA2106E

CLOSED THROTTLE POSITION AND WIDE OPEN THROTTLE POSITION CIR-CUIT
AT-171
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Revision: November 2009 2006 QX56
CLOSED THROTTLE POSITION AND WIDE OPEN THROTTLE POSITION CIR-
CUIT
PFP:18002
CONSULT-II Reference ValueECS00CJV
Diagnostic ProcedureECS00CJW
1. CHECK CAN COMMUNICATION LINE
Perform the self-diagnosis. Refer to AT- 8 6 , "
SELF-DIAGNOSTIC RESULT MODE" .
Is a malfunction in the CAN communication indicated in the results?
YES >> Check CAN communication line. Refer to AT- 9 6 , "DTC U1000 CAN COMMUNICATION LINE" .
NO >> GO TO 2.
2. CHECK THROTTLE POSITION SIGNAL CIRCUIT
With CONSULT-II
1. Turn ignition switch “ON”. (Do not start engine.)
2. Select “ECU INPUT SIGNALS” in “DATA MONITOR” mode for
“A/T ” with CONSULT-II.
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-II.

Open circuit or short to ground or short to power in harness or connectors.

Pin terminals for damage or loose connection with harness connector.
Item name Condition Display value
CLSD THL POS Released accelerator pedal.
ON
Fully depressed accelerator pedal. OFF
W/O THL POS Fully depressed accelerator pedal.
ON
Released accelerator pedal. OFF
Accelerator Pedal OperationMonitor Item
CLSD THL POS W/O THL POS
Released ONOFF
Fully depressed OFFON
PCIA0070E

AT-172
BRAKE SIGNAL CIRCUIT
Revision: November 20092006 QX56
BRAKE SIGNAL CIRCUITPFP:25320
CONSULT-II Reference ValueECS00CJX
Diagnostic ProcedureECS00CJY
1. CHECK CAN COMMUNICATION LINE
Perform the self-diagnosis. Refer to AT- 8 6 , "
SELF-DIAGNOSTIC RESULT MODE" .
Is a malfunction in the CAN communication indicated in the results?
YES >> Check CAN communication line. Refer to AT- 9 6 , "DTC U1000 CAN COMMUNICATION LINE" .
NO >> GO TO 2.
2. CHECK STOP LAMP SWITCH CIRCUIT
With CONSULT-II
1. Turn ignition switch “ ON”. (Do not start engine.)
2. Select “ECU INPUT SIGNALS ” in “DATA MONITOR” mode for
“A/T ” with CONSULT-II.
3. Read out ON/OFF switching action of the “BRAKE SW”.
OK or NG
OK >> INSPECTION END
NG >> GO TO 3.
3. CHECK STOP LAMP SWITCH
Check continuity between stop lamp switch harness connector termi-
nals 3 and 4.
Check stop lamp switch after adjusting brake pedal — refer to
BR-6, "
BRAKE PEDAL" .
OK or NG
OK >> INSPECTION END
NG >> Check the following items. If NG, repair or replace dam- aged parts.

Harness for short or open between battery and stop lamp switch.

Harness for short or open between stop lamp switch and combination meter.
Item name Condition Display value
BRAKE SW Depressed brake pedal.
ON
Released brake pedal. OFF
PCIA0070E
ConditionContinuity
When brake pedal is depressed Yes
When brake pedal is released No
WCIA0559E