2010 INFINITI QX56 ecm

EC-332
< COMPONENT DIAGNOSIS >[VK56DE]
P1564 ASCD STEERING SWITCH
P1564 ASCD STEERING SWITCH
Component DescriptionINFOID:0000000005149391
ASCD steering switch has variant values of electrical
resistance for each button. ECM reads voltage variation
of switch, and determines which button is operated.
Refer to EC-33, "
System Description" for the ASCD function.
On Board Diagn osis LogicINFOID:0000000005149392
•This self-diagnosis has the one trip detection logic.
• The MIL will not light up for this self-diagnosis.
NOTE:
If DTC P1564 is displayed with DTC P0605, first pe rform the trouble diagnosis for DTC P0605. Refer to
EC-286, "
On Board Diagnosis Logic".
DTC Confirmation ProcedureINFOID:0000000005149393
1. If DTC Confirmation Procedure has been previously conducted, always perform the following procedure
before conducting the next step.
a. Turn ignition switch OFF and wait at least 10 seconds.
b. Turn ignition switch ON.
c. Turn ignition switch OFF and wait at least 10 seconds.
2. Turn ignition switch ON.
3. Wait at least 10 seconds.
4. Press MAIN switch for at least 10 seconds, then release it and wait at least 10 seconds.
5. Press CANCEL switch for at least 10 seconds, then release it and wait at least 10 seconds.
6. Press RESUME/ACCELERATE switch for at least 10 seconds, then release it and wait at least 10 sec-
onds.
7. Press SET/COAST switch for at least 10 seconds , then release it and wait at least 10 seconds.
8. Check DTC.
9. If DTC is detected, go to EC-332, "
Diagnosis Procedure".
Diagnosis ProcedureINFOID:0000000005149394
1.CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten three ground screws on the body.
PBIB2640E
DTC No. Trouble Diagnosi s NameDTC Detecting Condition Possible Cause
P1564
1564 ASCD steering switch • An excessively high voltage signal from the ASCD
steering switch is sent to ECM.
• ECM detects that input signal from the ASCD steer- ing switch is out of the specified range.
• ECM detects that the ASCD steering switch is stuck ON. • Harness or connectors
(The switch circuit is open or
shorted.)
• ASCD steering switch
• Combination meter (spiral cable)
•ECM
Revision: April 20092010 QX56

P1564 ASCD STEERING SWITCHEC-333
< COMPONENT DIAGNOSIS > [VK56DE]
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Refer to
EC-85, "Ground Inspection".
OK or NG
OK >> GO TO 2.
NG >> Repair or replace ground connections.
2.CHECK ASCD STEERING SWITCH CIRCUIT
With CONSULT-III
1. Turn ignition switch ON.
2. Select “MAIN SW”, “CANCEL SW”, RESUME/ACC SW” and “SET SW” in “DATA MONITOR” mode with
CONSULT-III.
3. Check each item indication under the following conditions.
Without CONSULT-III
1. Turn ignition switch ON.
2. Check voltage between ECM terminal 99 and ground with press- ing each button.
OK or NG
OK >> GO TO 8.
NG >> GO TO 3.
3.CHECK ASCD STEERING SWITCH GRO UND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
BBIA0354E
Switch Monitor item Condition Indication
MAIN switch MAIN SWPressed ON
Released OFF
CANCEL switch CANCEL SWPressed ON
Released OFF
RESUME/ACCELERATE
switch RESUME/ACC SWPressed ON
Released OFF
SET/COAST switch SET SW Pressed ON
Released OFF
Switch Condition Voltage [V]
MAIN switch Pressed
Approx. 0
Released Approx. 4
CANCEL switch Pressed
Approx. 1
Released Approx. 4
RESUME/ACCELERATE
switch Pressed Approx.
3
Released Approx. 4
SET/COAST switch Pressed
Approx. 2
Released Approx. 4
PBIB0311E
Revision: April 20092010 QX56

EC-334
< COMPONENT DIAGNOSIS >[VK56DE]
P1564 ASCD STEERING SWITCH
2. Disconnect combination switch harness connector M102.
3. Disconnect ECM harness connector.
4. Check harness continuity between combination switch terminal
15 and ECM terminal 67.
Refer to Wiring Diagram.
5. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 5.
NG >> GO TO 4.
4.DETECT MALFUNCTIONING PART
Check the following.
• Harness connectors M31, E152
• Harness connectors E5, F14
• Combination switch (spiral cable)
• Harness for open and short between ECM and combination switch
>> Repair open circuit or short to ground or short to power in harness or connectors.
5.CHECK ASCD STEERING SWITCH INPUT SI GNAL CIRCUIT FOR OPEN AND SHORT
1. Check harness continuity between ECM terminal 99 and combination switch terminal 14. Refer to Wiring Diagram.
2. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 7.
NG >> GO TO 6.
6.DETECT MALFUNCTIONING PART
Check the following.
• Harness connectors M31, E152
• Combination switch (spiral cable)
• Harness for open and short between ECM and combination switch
>> Repair open circuit or short to ground or short to power in harness or connectors.
7.CHECK ASCD STEERING SWITCH
Refer to EC-334, "
Component Inspection".
OK or NG
OK >> GO TO 8.
NG >> Replace ASCD steering switch.
8.CHECK INTERMITTENT INCIDENT
Refer to GI-35, "
How to Check Terminal" and GI-38, "Intermittent Incident".
>> INSPECTION END
Component InspectionINFOID:0000000005149395
ASCD STEERING SWITCH
1. Disconnect combination switch (spiral cable) harness connector M102. Continuity should exist.
BBIA0362E
Continuity should exist.
Revision: April 20092010 QX56

EC-336
< COMPONENT DIAGNOSIS >[VK56DE]
P1568 ICC FUNCTION
P1568 ICC FUNCTION
On Board Diagn
osis LogicINFOID:0000000005149396
•This self-diagnosis has the one trip detection logic.
• The MIL will not light up for this self-diagnosis.
NOTE:
• If DTC P1568 is displayed with DTC UXXXX, first perform the trouble diagnosis for DTC UXXXX.
• If DTC P1568 is displayed with DTC P0605, first perform the trouble diagno sis for DTC P0605. Refer
to EC-286, "
On Board Diagnosis Logic".
• If DTC P1568 is displayed with DTC P0607, first perform the trouble diagno sis for DTC P0607. Refer
to EC-288, "
On Board Diagnosis Logic".
DTC Confirmation ProcedureINFOID:0000000005149397
CAUTION:
Always drive vehicle at a safe speed.
NOTE:
If DTC Confirmation Procedure has been previously conducted, always perform the following procedure
before conducting the next step.
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 4 may be conducted with the drive 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.
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).
4. Press SET/COAST switch.
5. Check DTC.
6. If DTC is detected, go to EC-336, "
Diagnosis Procedure".
Diagnosis ProcedureINFOID:0000000005149398
1.REPLACE ICC UNIT
1. Replace ICC unit.
2. Perform CCS-8
.
3. Check DTC of ICC unit. Refer to CCS-18
.
>> INSPECTION END
DTC No. Trouble Diagnosis
Name DTC Detecting Condit
ion Possible Cause
P1568
1568 ICC function ECM detects a difference between signals
from ICC unit is out of specified range. • Harness or connectors
(The CAN communication line is open or
shorted.)
• ICC unit
•ECM
Revision: April 20092010 QX56

P1572 ICC BRAKE SWITCHEC-337
< COMPONENT DIAGNOSIS > [VK56DE]
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P1572 ICC BRAKE SWITCH
Component DescriptionINFOID:0000000005149399
When the brake pedal is depressed, ICC brake switch is turned OFF
and stop lamp switch is turned ON. ECM detects the state of the
brake pedal by this input of two kinds (ON/OFF signal).
Refer to
CCS-13
for the ICC function.
On Board Diagnosis LogicINFOID:0000000005149400
•This diagnosis has the on e trip detection logic.
• The MIL will not light up for this self-diagnosis.
NOTE:
• If DTC P1572 is displayed with DT C P0605, first perform the trouble diagnosis for DTC P0605. Refer
to EC-286, "
On Board Diagnosis Logic".
• This self-diagnosis has the one trip detection logic. When malfunction A is detected, DTC is not
stored in ECM memory. And in that case, 1st trip DTC and 1st trip freeze frame data are displayed.
1st trip DTC is erased when ignition switch OFF. And even when ma lfunction A is detected in two
consecutive trips, DTC is not stored in ECM memory.
DTC Confirmation ProcedureINFOID:0000000005149401
CAUTION:
Always drive vehicle at a safe speed.
NOTE:
• Procedure for malfunction B is not described here. It takes extremely long time to complete procedure for
malfunction B. By performing procedure for malfunction A, the incident that causes malfunction B can be
detected.
• If DTC Confirmation Procedure has been previously conducted, always perform the following procedure
before conducting the next step.
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:
Steps 3 and 6 may be conducted with the drive wheels li fted in the shop or by driving the vehicle. If a
road test is expected to be easier, it is unnecessary to lift the vehicle.
1. Start engine (VDC switch OFF).
2. Press MAIN switch and make sure that CRUISE lamp lights up.
3. Drive the vehicle for at least 5 consecutive seconds under the following conditions.
BBIA0470E
DTC No. Trouble diagnosis
name DTC detecting condition
Possible cause
P1572
1572 ICC brake switch A)
When vehicle speed is above 30 km/h (19
MPH), ON signals from the stop lamp
switch and the ICC brake switch are sent to
ECM at the same time. • Harness or connectors
(The stop lamp switch circuit is shorted.)
• Harness or connectors
(The ICC brake switch circuit is shorted.)
•Stop lamp switch
• ICC brake switch
• ICC brake hold relay
• Incorrect stop lamp switch installation
• Incorrect ICC brake switch installation
•ECM
B)
ICC brake switch signal is not sent to ECM
for extremely long time while the vehicle is
driving
Revision: April 20092010 QX56

EC-338
< COMPONENT DIAGNOSIS >[VK56DE]
P1572 ICC BRAKE SWITCH
4. Check 1st trip DTC.
5. If 1st trip DTC is detected, go to
EC-338, "
Diagnosis Procedure".
If 1st trip DTC is not detec ted, go to the following step.
6. Drive the vehicle for at least 5 consecutive seconds under the following conditions.
7. Check 1st trip DTC.
8. If 1st trip DTC is detected, go to EC-338, "
Diagnosis Procedure".
Diagnosis ProcedureINFOID:0000000005149402
1.CHECK OVERALL FUNCTION-I
With CONSULT-III
1. Turn ignition switch ON.
2. Select “BRAKE SW1” in “DAT A MONITOR” mode with CONSULT-III.
3. Check “BRAKE SW1” indication under the following conditions.
Without CONSULT-III
1. Turn ignition switch ON.
2. Check voltage between ECM terminal 108 and ground under the following conditions.
OK or NG
OK >> GO TO 2.
NG >> GO TO 3.
2.CHECK OVERALL FUNCTION-II
With CONSULT-III
Check “BRAKE SW2” indication in “DATA MONITOR” mode.
Without CONSULT-III
VHCL SPEED SE More than 30 km/h (19 MPH)
Selector lever Suitable position
VHCL SPEED SE More than 30 km/h (19 MPH)
Selector lever Suitable position
Driving location Depress the brake pedal for more than
five seconds so as not to come off from
the above-mentioned vehicle speed.
CONDITION
INDICATION
Brake pedal: Slightly depressed OFF
Brake pedal: Fully released ON
CONDITIONVOLTAGE
Brake pedal: Slightly depressed Approximately 0V
Brake pedal: Fully released Battery voltage
MBIB0061E
CONDITIONINDICATION
Brake pedal: Fully released OFF
Brake pedal: Slightly depressed ON
Revision: April 20092010 QX56

P1572 ICC BRAKE SWITCHEC-339
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Check voltage between ECM terminal 101 and ground under the fol-
lowing conditions.
OK or NG
OK >> GO TO 15.
NG >> GO TO 9.
3.CHECK ICC BRAKE SWITCH POWER SUPPLY CIRCUIT-I
1. Turn ignition switch OFF.
2. Disconnect ICC brake switch harness connector.
3. Turn ignition switch ON.
4. Check voltage between ICC brake switch terminal 1 and ground with CONSULT-III or tester.
OK or NG
OK >> GO TO 7.
NG >> GO TO 4.
4.CHECK ICC BRAKE SWITCH PO WER SUPPLY CIRCUIT-II
1. Turn ignition switch OFF.
2. Disconnect ICC brake hold relay.
3. Check harness continuity between ICC brake switch terminal 1 and ICC brake hold relay terminal 3
Refer to Wiring Diagram.
CONDITION VOLTAGE
Brake pedal: Fully released Approximately 0V
Brake pedal: Slightly depressed Battery voltage
PBIB1537E
BBIA0470E
Voltage: Battery voltage
PBIB0857E
BBIA0471E
Revision: April 20092010 QX56

EC-340
< COMPONENT DIAGNOSIS >[VK56DE]
P1572 ICC BRAKE SWITCH
4. Also 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.CHECK ICC BRAKE HOLD RE
LAY POWER SUPPLY CIRCUIT
1. Turn ignition switch ON.
2. Check the voltage between ICC brake hold relay terminal 4 and ground with CONSULT-III or tester.
OK or NG
OK >> GO TO 14.
NG >> GO TO 6.
6.DETECT MALFUNCTIONING PART
Check the following.
• Harness connectors M31, E152
• Fuse block (J/B) connector M4
• 10 A fuse (No.15)
• Harness for open or short between ICC brake hold relay and fuse
>> Repair open circuit or short to ground or short to power in harness or connectors.
7.CHECK ICC BRAKE SWITCH INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check harness continuity between ICC brake switch terminal 2 and ECM terminal 108, ICC brake switch
terminal 2 and ICC unit terminal 29.
Refer Wiring Diagram.
4. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 8.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
8.CHECK ICC BRAKE SWITCH
Refer to EC-343, "
Component Inspection".
OK or NG
OK >> GO TO 15.
NG >> Replace ICC brake switch.
9.CHECK POWER SUPPLY CIRCUIT
1. Turn ignition switch OFF. Continuity should exist.
Voltage: Battery voltage
MBIB0059E
Continuity should exist.
Revision: April 20092010 QX56