2011 INFINITI QX56 steering

P1564 ASCD STEERING SWITCHEC-433
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5.DETECT MALFUNCTIONING PART
Check the following.
 Combination switch (spiral cable)
 Harness for open and short between ECM and combination switch
>> Repair open circuit, short to ground or short to power in harness or connectors.
6.CHECK ASCD STEERING SWITCH
Refer to EC-433, "
Component Inspection (ASCD Steering Switch)".
Is the inspection result normal?
YES >> GO TO 7.
NO >> Replace ASCD steering switch. Refer to ST-33, "
Removal and Installation".
7.CHECK INTERMITTENT INCIDENT
Refer to GI-40, "
Intermittent Incident".
>> INSPECTION END
Component Inspection (A SCD Steering Switch)INFOID:0000000006217937
1.CHECK ASCD STEERING SWITCH
1. Turn ignition switch OFF.
2. Disconnect combination switch (spiral cable) harness connector M302.
3. Check resistance between combination switch har ness connector terminals under the following condi-
tions.
Is the inspection result normal?
YES >> INSPECTION END
NO >> Replace ASCD steering switch. Refer to ST-33, "
Removal and Installation".
Combination switch
Condition Resistance ( Ω)
Connector Terminals
M302 13 and 16 MAIN switch: Pressed Approx. 0
CANCEL switch: Pressed Approx. 250
SET/COAST switch: Pressed Approx. 660
RESUME/ACCELERATE switch: Pressed Approx. 1,480
All ASCD steering switches: Released Approx. 4,000
Revision: 2010 May2011 QX56

EC-434
< DTC/CIRCUIT DIAGNOSIS >[VK56VD]
P1564 ICC STEERING SWITCH
P1564 ICC STEERING SWITCH
DTC LogicINFOID:0000000006217938
DTC DETECTION LOGIC
NOTE:
If DTC P1564 is displayed with DTC P0605, first pe
rform the trouble diagnosis for DTC P0605. Refer to
EC-376, "
DTC Logic".
DTC CONFIRMATION PROCEDURE
1.PRECONDITIONING
1. Turn ignition switch OFF and wait at least 10 seconds.
2. Turn ignition switch ON.
3. Turn ignition switch OFF and wait at least 10 seconds.
>> GO TO 2.
2.PERFORM DTC CONFIRMATION PROCEDURE
1. Turn ignition switch ON and wait at least 10 seconds.
2. Press MAIN switch for at least 10 seconds, then release it and wait at least 10 seconds.
3. Press CANCEL switch for at least 10 seconds , then release it and wait at least 10 seconds.
4. Press RESUME/ACCELERATE switch for at least 10 seconds, then release it and wait at least 10 sec-
onds.
5. Press SET/COAST switch for at least 10 seconds , then release it and wait at least 10 seconds.
6. Press DISTANCE switch for at least 10 seconds , then release it and wait at least 10 seconds.
7. Press LDP switch for at least 10 seconds, t hen release it at wait at least 10 seconds.
8. Check DTC.
Is DTC detected?
YES >> Go to EC-434, "Diagnosis Procedure".
NO >> INSPECTION END
Diagnosis ProcedureINFOID:0000000006217939
1.CHECK ICC STEERING SWITCH CIRCUIT
1. Turn ignition switch ON.
2. Check the voltage between ECM harness connector terminals under the following conditions.
DTC No. Trouble diagnosis name
(Trouble diagnosis content) DTC detecting condition Possible cause
P1564 ASCD SW
(ICC steering switch)  An excessively high voltage signal from the
ICC steering switch is sent to ECM.
 ECM detects that input signal from the ICC steering switch is out of the specified range.
 ECM detects that the ICC steering switch is stuck ON.  Harness or connectors
(The switch circuit is open or shorted.)
 ICC steering switch
ECM
Revision: 2010 May2011 QX56

P1564 ICC STEERING SWITCHEC-435
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Is the inspection result normal?
YES >> GO TO 7.
NO >> GO TO 2.
2.CHECK ICC STEERING SWITCH GRO
UND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Disconnect combination switch harness connector.
4. Check the continuity between combination switch and ECM harness connector.
5. Also check harness for short to ground and short to power.
Is the inspection result normal?
YES >> GO TO 4.
NO >> GO TO 3.
3.DETECT MALFUNCTIONING PART
Check the following.
 Combination switch (spiral cable)
 Harness for open and short between ECM and combination switch
>> Repair open circuit, short to ground or short to power in harness or connectors.
4.CHECK ICC STEERING SWITCH INPUT SI GNAL CIRCUIT FOR OPEN AND SHORT
1. Check the continuity between combination switch and ECM harness connector.
2. Also check harness for short to ground and short to power.
Is the inspection result normal?
YES >> GO TO 6.
NO >> GO TO 5.
5.DETECT MALFUNCTIONING PART
Check the following.
 Combination switch (spiral cable)
 Harness for open and short between ECM and combination switch
ECM
Condition Voltage (V)
Connector +–
Te r m i n a l Te r m i n a l
E80 128
(ICC steering switch signal) 130MAIN switch: Pressed Approx. 0
DYNAMIC DRIVER ASSISTANCE switch: Pressed Approx. 1.0
CANCEL switch: Pressed Approx. 1.9
DISTANCE switch: Pressed Approx. 2.6
SET/COAST switch: Pressed Approx. 3.2
RESUME/ACCELERATE switch: Pressed Approx. 3.7
All ICC steering switches: Released Approx. 4.2
Combination switch ECM
Continuity
Connector Terminal Connector Terminal
— 32 E80 130 Existed
Combination switch ECM Continuity
Connector Terminal Connector Terminal
— 25 E80 130 Existed
Revision: 2010 May2011 QX56

EC-436
< DTC/CIRCUIT DIAGNOSIS >[VK56VD]
P1564 ICC STEERING SWITCH
>> Repair open circuit, short to ground or short to power in harness or connectors.
6.CHECK ICC STEERING SWITCH
Refer to EC-436, "
Component Inspection (ICC Steering Switch)".
Is the inspection result normal?
YES >> GO TO 7.
NO >> Replace ICC steering switch. Refer to ST-33, "
Removal and Installation".
7.CHECK INTERMITTENT INCIDENT
Refer to GI-40, "
Intermittent Incident".
>> INSPECTION END
Component Inspection (ICC Steering Switch)INFOID:0000000006217940
1.CHECK ICC STEERING SWITCH
1. Turn ignition switch OFF.
2. Disconnect combination switch (spiral cable) harness connector M302.
3. Check resistance between combination switch harness connector terminals under the following condi-
tions.
Is the inspection result normal?
YES >> INSPECTION END
NO >> Replace ICC steering switch. Refer to ST-33, "
Removal and Installation".
Combination switch
Condition Resistance ( Ω)
Connector Terminals
M302 13 and 16 MAIN switch: Pressed Approx. 0
DYNAMIC DRIVER ASSISTANCE switch: Pressed Approx. 270
CANCEL switch: Pressed Approx. 620
DISTANCE switch: Pressed Approx. 1,100
SET/COAST switch: Pressed Approx. 1,810
RESUME/ACCELERATE switch: Pressed Approx. 3,000
All ICC steering switches: Released Approx. 5,420
Revision: 2010 May2011 QX56

P1568 ICC FUNCTIONEC-437
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P1568 ICC FUNCTION
DTC LogicINFOID:0000000006217941
DTC DETECTION LOGIC
NOTE:

If DTC P1568 is displayed with DTC UXXXX, perform the trouble diagnosis for DTC UXXXX.
 If DTC P1568 is displayed with DTC P0605, perform the trouble diagnosis for DTC P0605. Refer to
EC-376, "
DTC Logic".
 If DTC P1568 is displayed with DTC P0607, perform the trouble diagnosis for DTC P0607. Refer to
EC-378, "
DTC Logic".
DTC CONFIRMATION PROCEDURE
1.PRECONDITIONING
1. Turn ignition switch OFF and wait at least 10 seconds.
2. Turn ignition switch ON.
3. Turn ignition switch OFF and wait at least 10 seconds.
TESTING CONDITION:
Step 2 may be conducted with the dr ive wheels lifted in the shop or by driving the vehicle. If a road test
is expected to be easier, it is unnecessary to lift the vehicle.
>> GO TO 2.
2.PERFORM DTC CONFIRMATION PROCEDURE
1. Turn ignition switch ON.
2. Press MAIN switch on ICC steering switch.
3. Drive the vehicle at more than 40 km/h (25 MPH). CAUTION:
Always drive vehicle at a safe speed.
4. Press SET/COAST switch.
5. Check DTC.
Is DTC detected?
YES >> Go to EC-437, "Diagnosis Procedure".
NO >> INSPECTION END
Diagnosis ProcedureINFOID:0000000006217942
1.REPLACE ADAS CONTROL UNIT
1. Replace ADAS control unit. Refer to DAS-63, "
Removal and Installation".
2. Check DTC of ADAS control unit. Refer to DAS-38, "
DTC Index".
>> INSPECTION END
DTC No. Trouble diagnosis name
(Trouble diagnosis content) DTC Detecting Condit
ion Possible Cause
P1568 ICC COMMAND VALUE
(ICC function) ECM detects a difference between signals
from ADAS control unit is out of specified
range.  Harness or connectors
(The CAN communication line is open or
shorted.)
 ADAS control unit
ECM
Revision: 2010 May2011 QX56

P2539, P2541, P2542 LOW FUEL PRESSURE SENSOR
EC-483
< DTC/CIRCUIT DIAGNOSIS > [VK56VD]
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P2539, P2541, P2542 LOW
FUEL PRESSURE SENSOR
DTC LogicINFOID:0000000006288355
DTC DETECTION LOGIC
DTC CONFIRMATION PROCEDURE
1.PRECONDITIONING
1. Turn ignition switch OFF and wait at least 10 seconds.
2. Turn ignition switch ON.
3. Turn ignition switch OFF and wait at least 10 seconds.
TESTING CONDITION:
Before performing the following procedure, confirm that battery voltage is 11 V or more at idle.
>> GO TO 2.
2.PERFORM DTC CONFIRMATION PROCEDURE
1. Start engine and let it idle for at least 60 seconds.
2. Check 1st trip DTC.
Is 1st trip DTC detected?
YES >> Proceed to EC-483, "Diagnosis Procedure".
NO >> INSPECTION END
Diagnosis ProcedureINFOID:0000000006288356
1.CHECK LOW FUEL PRESSURE SENSOR POWER SUPPLY-I
1. Turn ignition switch OFF.
2. Disconnect low fuel pressure sensor connector.
3. Turn ignition switch ON.
4. Check the voltage between low fuel pressure sensor harness connector terminals.
Inspection result normal?
YES >> GO TO 6.
NO >> GO TO 2.
2.CHECK LOW FUEL PRESSURE SENSOR POWER SUPPLY-II
Check the voltage between low fuel pressure sensor harness connector and the ground.
DTC No. Trouble diagnosis name
(Trouble diagnosis content) DTC detecting condition Possible cause
P2539 LOW FUEL PRES SEN
(Low fuel pressure sensor
circuit low input and high in-
put) Signal voltage from the low fuel pressure
sensor remains at more than 4.84 V / less
than 0.3 V for 5 seconds or more.  Harness or connectors
(Low fuel pressure sensor circuit is open
or shorted.)
(Power steering pressure sensor circuit is
open or shorted.)
(Cooling fan speed sensor circuit is open
or shorted.)
(FRP sensor circuit is open or shorted.)
 Low fuel pressure sensor
 Power steering pressure sensor
 Cooling fan speed sensor
 FRP sensor
P2541
LOW FUEL PRES SEN
(Low fuel pressure sensor
circuit low input) Signal voltage from the low fuel pressure
sensor remains at less than 0.49 V for 5 sec-
onds or more.
P2542 LOW FUEL PRES SEN
(Low fuel pressure sensor
circuit high input) Signal voltage from the low fuel pressure
sensor remains at more than 4.1 V for 5 sec-
onds or more.
Low fuel pressure sensor
Vo l ta g e
(Approx.)
Connector +
−
terminal
F25 3 1 5 V
Revision: 2010 May2011 QX56

EC-484
< DTC/CIRCUIT DIAGNOSIS >[VK56VD]
P2539, P2541, P2542 LOW
FUEL PRESSURE SENSOR
Is inspection result normal?
YES >> GO TO 4.
NO >> GO TO 3.
3.CHECK SENSOR POWER SUPPLY CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check harness connector for short to power and short to ground, between the following terminals.
Is inspection result normal?
YES >> Perform the trouble diagnosis for power supply circuit. Refer to EC-168, "Diagnosis Procedure".
NO >> Repair or replace error-detected parts.
4.CHECK LOW FUEL PRESSURE SENSOR GROUND CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check the continuity between low fuel pressu re sensor harness connector and ECM harness connector.
Is inspection result normal?
YES >> GO TO 5.
NO >> Repair or replace error-detected parts.
5.CHECK ECM GROUND CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check the continuity between ECM harness connector and the ground.
Is inspection result normal?
YES >> Check intermittent incident. Refer to GI-40, "Intermittent Incident".
+
−Voltag e
(Approx.)
Low fuel pressure sensor
Connector Terminal F25 3 Ground 5 V
ECM Sensor
Connector Terminal Name Connector Terminal
F 111 27Power steering pressure sensor F35 1
Low fuel pressure sensor F25 3
Cooling fan speed sensor F39 2
28 FRP sensor F26 1
+ −
Continuity
Low fuel pressure sensor ECM
Connector Terminal Connector Terminal F25 1 F111 45 Existed
ECM Ground Continuity
Connector Terminal
F 111 5
Ground Existed
E80 11 4
11 5
174
175
Revision: 2010 May2011 QX56

INFORMATION DISPLAY (ASCD)EC-511
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INFORMATION DISPLAY (ASCD)
Component Function CheckINFOID:0000000006218015
1.CHECK INFORMATION DISPLAY
1. Start engine.
2. Press MAIN switch on ASCD steering switch.
3. Drive the vehicle at more than 40 km/h (25 MPH). CAUTION:
Always drive vehicle at a safe speed.
4. Press SET/COAST switch.
5. Check that the reading of the speedom eter shows the same value as the set speed indicated in the infor-
mation display while driving the vehicle on a flat road.
Is the inspection result normal?
YES >> INSPECTION END
NO >> Go to EC-511, "
Diagnosis Procedure".
Diagnosis ProcedureINFOID:0000000006218016
1.CHECK DTC
Check that DTC UXXXX or P0500 is not displayed.
Is the inspection result normal?
YES >> GO TO 2.
NO-1 >> Perform trouble diagnosis for DTC UXXXX.
NO-2 >> Perform trouble diagnosis for DTC P0500. Refer to EC-356, "
DTC Logic".
2.CHECK DTC WITH “COMBINATION METER”
Refer to MWI-30, "
CONSULT-III Function".
Is the inspection result normal?
YES >> GO TO 3.
NO >> Perform trouble diagnosis for DTC indicated.
3.CHECK INTERMITTENT INCIDENT
Refer to GI-40, "
Intermittent Incident".
Is the inspection result normal?
YES >> Replace combination meter.
NO >> Repair or replace.
Revision: 2010 May2011 QX56