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EC-554Revision: October 2005
DTC P1564 ASCD STEERING SWITCH
2005 QX56
Wiring DiagramUBS00L10
BBWA2486E
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DTC P1564 ASCD STEERING SWITCH
EC-555
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Specification data are reference values and are measured between each terminal and ground.
CAUTION:
Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.
Diagnostic ProcedureUBS00L11
1. CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten three ground screws on the body.
Refer to EC-162, "
Ground Inspection" .
OK or NG
OK >> GO TO 2.
NG >> Repair or replace ground connections.
TER-
MINAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
67 B Sensor ground[Engine is running]
Warm-up condition
Idle speedApproximately 0V
99 G/Y ASCD steering switch[Ignition switch: ON]
ASCD steering switch: OFFApproximately 4V
[Ignition switch: ON]
MAIN switch: ONApproximately 0V
[Ignition switch: ON]
CANCEL switch: ONApproximately 1V
[Ignition switch: ON]
RESUME/ACCELERATTTE switch: ONApproximately 3V
[Ignition switch: ON]
SET/COAST switch: ONApproximately 2V
BBIA0354E
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EC-556Revision: October 2005
DTC P1564 ASCD STEERING SWITCH
2005 QX56
2. CHECK ASCD STEERING SWITCH CIRCUIT
With CONSULT-II
1. Turn ignition switch ON.
2. Select “MAIN SW”, “CANCEL SW”, RESUME/ACC SW” and “SET SW” in “DATA MONITOR” mode with
CONSULT-II.
3. Check each item indication under the following conditions.
Without CONSULT-II
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 GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
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.
Switch Monitor item Condition Indication
MAIN switch MAIN SWPressed ON
Released OFF
CANCEL switch CANCEL SWPressed ON
Released OFF
RESUME/ACCELERATE
switchRESUME/ACC SWPressed ON
Released OFF
SET/COAST switch SET SWPressed ON
Released OFF
SEC0 06 D
Switch Condition Voltage [V]
MAIN switchPressed Approx. 0
Released Approx. 4
CANCEL switchPressed Approx. 1
Released Approx. 4
RESUME/ACCELERATE
switchPressed Approx. 3
Released Approx. 4
SET/COAST switchPressed Approx. 2
Released Approx. 4
PBIB0 311 E
Continuity should exist.
BBIA0362E
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DTC P1564 ASCD STEERING SWITCH
EC-557
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4. DETECT MALFUNCTIONING PART
Check the following.
Harness connectors M31, E152
Harness connectors E19, F33
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 SIGNAL 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-558, "
Component Inspection" .
OK or NG
OK >> GO TO 8.
NG >> Replace ASCD steering switch. Refer to AV- 4 7 , "
Removal and Installation of Steering Wheel
Audio Control Switches" .
8. CHECK INTERMITTENT INCIDENT
Refer to EC-156, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
>>INSPECTION END Continuity should exist.
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EC-558Revision: October 2005
DTC P1564 ASCD STEERING SWITCH
2005 QX56
Component InspectionUBS00L12
ASCD STEERING SWITCH
1. Disconnect combination switch (spiral cable) harness connector M102.
2. Check continuity between combination switch (spiral cable) ter-
minals 14 and 15 with pushing each switch.
Switch Condition Resistance [Ω]
MAIN switchPressed Approx. 0
Released Approx. 4,000
CANCEL switchPressed Approx. 250
Released Approx. 4,000
RESUME/ACCELERATE
switchPressed Approx. 1,480
Released Approx. 4,000
SET/COAST switchPressed Approx. 660
Released Approx. 4,000
PBIB1673E
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DTC P1568 ICC FUNCTION
EC-559
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DTC P1568 ICC FUNCTIONPFP:18995
On Board Diagnosis LogicUBS00L1T
This self-diagnosis has the one trip detection logic.
The MIL will not light up for this diagnosis.
NOTE:
If DTC P1568 is displayed with DTC U1000, U1001, first perform the trouble diagnosis for DTC
U1000, U1001. Refer to EC-163, "
DTC U1000, U1001 CAN COMMUNICATION LINE" .
If DTC P1568 is displayed with DTC P0605, first perform the trouble diagnosis for DTC P0605.
Refer to EC-383, "
DTC P0605 ECM".
DTC Confirmation ProcedureUBS00L1U
CAUTION:
Always drive vehicle at a safe speed.
NOTE:
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
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.
WITH CONSULT-II
1. Turn ignition switch ON.
2. Select “DATA MONITOR” mode with CONSULT-II.
3. Press MAIN switch on ICC steering switch.
4. Drive the vehicle at more than 40 km/h (25 MPH).
5. Press SET/COAST switch.
6. If DTC is detected, go to EC-559, "
Diagnostic Procedure" .
WITH GST
Follow the procedure “WITH CONSULT-II” above.
Diagnostic ProcedureUBS00L1V
1. REPLACE ICC UNIT
1. Replace ICC unit.
2. Perform ACS-9, "
ACTION TEST" .
3. Check DTC of ICC unit. Refer to ACS-36, "
TROUBLE DIAGNOSIS FOR SELF-DIAGNOSTIC ITEMS" .
>>INSPECTION END
DTC No.Trouble Diagnosis
NameDTC Detecting Condition Possible Cause
P1568
1568ICC functionECM 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
SEF 0 58 Y
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EC-560Revision: October 2005
DTC P1572 ICC BRAKE SWITCH
2005 QX56
DTC P1572 ICC BRAKE SWITCHPFP:25320
Component DescriptionUBS00L1W
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 ACS-6, "
DESCRIPTION" for the ICC function.
CONSULT-II Reference Value in Data Monitor ModeUBS00L1X
Specification data are reference values.
On Board Diagnosis LogicUBS00L1Y
This diagnosis has the one trip detection logic.
The MIL will not light up for this diagnosis.
NOTE:
If DTC P1572 is displayed with DTC P0605, first perform the trouble diagnosis for DTC P0605.
Refer to EC-383, "
DTC P0605 ECM" .
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 malfunction A is detected in two
consecutive trips, DTC is not stored in ECM memory.
BBIA0470E
MONITOR ITEM CONDITION SPECIFICATION
BRAKE SW1
(ICC brake switch)
Ignition switch: ONBrake pedal: Fully released ON
Brake pedal: Slightly depressed OFF
BRAKE SW2
(stop lamp switch)
Ignition switch: ONBrake pedal: Fully released OFF
Brake pedal: Slightly depressed ON
DTC No.Trouble diagnosis
nameDTC detecting condition Possible cause
P1572
1572ICC brake switchA)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
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DTC P1572 ICC BRAKE SWITCH
EC-561
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DTC Confirmation ProcedureUBS00L1Z
CAUTION:
Always drive vehicle at a safe speed.
NOTE:
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait
at least 10 seconds before conducting the next test.
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.
TESTING CONDITION:
Steps 4 and 5 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.
WITH CONSULT-II
1. Start engine (VDC switch OFF).
2. Select “DATA MONITOR” mode with CONSULT-II.
3. Press MAIN switch and make sure that CRUISE lamp lights up.
4. Drive the vehicle for at least 5 consecutive seconds under the
following conditions.
If 1st trip DTC is detected, go to EC-563, "
Diagnostic Procedure"
.
If 1st trip DTC is not detected, go to the following step.
5. Drive the vehicle for at least 5 consecutive seconds under the following conditions.
6. If 1st trip DTC is detected, go to EC-563, "
Diagnostic Procedure" .
WITH GST
Follow the procedure “WITH CONSULT-II” above.
VHCL SPEED SE More than 30 km/h (19 MPH)
Selector lever Suitable position
PBIB2386E
VHCL SPEED SE More than 30 km/h (19 MPH)
Selector lever Suitable position
Driving locationDepress the brake pedal for more than
five seconds so as not to come off from
the above-mentioned vehicle speed.