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EC-546Revision: October 2005
DTC P1564 ICC STEERING SWITCH
2005 QX56
DTC Confirmation ProcedureUBS00L1P
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.
WITH CONSULT-II
1. Turn ignition switch ON.
2. Select “DATA MONITOR” mode with CONSULT-II.
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 seconds.
7. Press SET/COAST switch for at least 10 seconds, then release
it and wait at least 10 seconds.
8. Press DISTANCE switch for at least 10 seconds, then release it
and wait at least 10 seconds.
9. If DTC is detected, go to EC-548, "
Diagnostic Procedure" .
WITH GST
Follow the procedure “WITH CONSULT-II” above.
SEF 0 58 Y
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DTC P1564 ICC STEERING SWITCH
EC-547
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Wiring DiagramUBS00L1Q
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EC-548Revision: October 2005
DTC P1564 ICC STEERING SWITCH
2005 QX56
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 ProcedureUBS00L1R
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 ICC steering switch[Ignition switch: ON]
ICC steering switch: OFFApproximately 4.3V
[Ignition switch: ON]
MAIN switch: PressedApproximately 0V
[Ignition switch: ON]
CANCEL switch: PressedApproximately 1.3V
[Ignition switch: ON]
RESUME/ACCELERATE switch: PressedApproximately 3.7V
[Ignition switch: ON]
SET/COAST switch: PressedApproximately 3V
[Ignition switch: ON]
DISTANCE switch: PressedApproximately 2.2V
BBIA0354E
Page 1740 of 3419

DTC P1564 ICC STEERING SWITCH
EC-549
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Revision: October 20052005 QX56
2. CHECK ICC STEERING SWITCH CIRCUIT
With CONSULT-II
1. Turn ignition switch ON.
2. Select “MAIN SW”, “CANCEL SW”, “RESUME/ACC SW”, “SET
SW” and “DIST SW” in “DATA MONITOR” mode with CON-
SULT-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.
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
DISTANCE switch DIST SWPressed ON
Released OFF
MBIB0064E
Switch Condition Voltage [V]
MAIN switchPressed Approx. 0
Released Approx. 4.3
CANCEL switchPressed Approx. 1.3
Released Approx. 4.3
RESUME/ACCELERATE
switchPressed Approx. 3.7
Released Approx. 4.3
SET/COAST switchPressed Approx. 3.0
Released Approx. 4.3
DISTANCE switchPressed Approx. 2.2
Released Approx. 4.3
PBIB0 311 E
Page 1741 of 3419

EC-550Revision: October 2005
DTC P1564 ICC STEERING SWITCH
2005 QX56
3. CHECK ICC STEERING SWITCH GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Disconnect combination switch 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 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 ICC 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 ICC STEERING SWITCH
Refer to EC-551, "
Component Inspection" .
OK or NG
OK >> GO TO 8.
NG >> Replace ICC steering switch.Continuity should exist.
Continuity should exist.
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DTC P1564 ICC STEERING SWITCH
EC-551
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Revision: October 20052005 QX56
8. CHECK INTERMITTENT INCIDENT
Refer to EC-156, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
>>INSPECTION END
Component InspectionUBS00L1S
ICC STEERING SWITCH
1. Disconnect combination switch (spiral cable) harness connector M102.
2. Check continuity between ICC steering switch terminals 1 and 2
with pushing each switch.
If NG, replace ICC steering switch.
Switch Condition Resistance [Ω]
MAIN switchPressed Approx. 0
Released Approx. 5,500
CANCEL switchPressed Approx. 310
Released Approx. 5,500
RESUME/ACCELERATE
switchPressed Approx. 2,600
Released Approx. 5,500
SET/COAST switchPressed Approx. 1,400
Released Approx. 5,500
DISTANCE switchPressed Approx. 740
Released Approx. 5,500
PBIB1673E
Page 1743 of 3419

EC-552Revision: October 2005
DTC P1564 ASCD STEERING SWITCH
2005 QX56
DTC P1564 ASCD STEERING SWITCHPFP:25551
Component DescriptionUBS00L0W
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-29, "
AUTOMATIC SPEED CONTROL DEVICE (ASCD)" for the ASCD function.
CONSULT-II Reference Value in Data Monitor ModeUBS00L0X
Specification data are reference values.
On Board Diagnosis LogicUBS00L0Y
This self-diagnosis has the one trip detection logic.
The MIL will not light up for this diagnosis.
NOTE:
If DTC P1564 is displayed with DTC P0605, first perform the trouble diagnosis for DTC P0605. Refer to
EC-383, "
DTC P0605 ECM".
PBIB2640E
MONITOR ITEM CONDITION SPECIFICATION
MAIN SW
Ignition switch: ONMAIN switch: Pressed ON
MAIN switch: Released OFF
CANCEL SW
Ignition switch: ONCANCEL switch: Pressed ON
CANCEL switch: Released OFF
RESUME/ACC SW
Ignition switch: ONRESUME/ACCELERATE switch: Pressed ON
RESUME/ACCELERATE switch: Released OFF
SET SW
Ignition switch: ONSET/COAST switch: Pressed ON
SET/COAST switch: Released OFF
DTC No. Trouble Diagnosis Name DTC Detecting Condition Possible Cause
P1564
1564ASCD steering switch
An excessively high voltage signal from the ASCD
steering switch is sent to ECM.
ECM detects that input signal from the ASCD
steering 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
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DTC P1564 ASCD STEERING SWITCH
EC-553
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Revision: October 20052005 QX56
DTC Confirmation ProcedureUBS00L0Z
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.
WITH CONSULT-II
1. Turn ignition switch ON.
2. Select “DATA MONITOR” mode with CONSULT-II.
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. If DTC is detected, go to EC-555, "
Diagnostic Procedure" .
WITH GST
Follow the procedure “WITH CONSULT-II” above.