Infiniti FX35 / FX45. Manual - part 425

DTC P1564 ASCD STEERING SWITCH

EC-461

< SERVICE INFORMATION >

[VQ35DE]

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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.

Diagnosis Procedure

INFOID:0000000001326325

1.

CHECK GROUND CONNECTIONS

1.

Turn ignition switch OFF.

2.

Loosen and retighten ground screw on the body. Refer to 

EC-144, "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”, “RESUME/ACC SW”, “SET SW” and “CANCEL SW” in “DATA MONITOR” mode with
CONSULT-III.

3.

Check each item indication under the following conditions.

TER-

MI-

NAL 

NO.

WIRE 

COLOR

ITEM

CONDITION

DATA (DC Voltage)

82

B/W

Sensor ground
(ASCD steering switch)

[Engine is running]
• Warm-up condition
• Idle speed

Approximately 0V

99

G/Y

ASCD steering switch

[Ignition switch: ON]
• ASCD steering switch: OFF

Approximately 4.0V

[Ignition switch: ON]
• MAIN switch: Pressed

Approximately 0V

[Ignition switch: ON]
• CANCEL switch: Pressed

Approximately 1.0V

[Ignition switch: ON]
• RESUME/ACCELERATE switch: Pressed

Approximately 3.0V

[Ignition switch: ON]
• SET/COAST switch: Pressed

Approximately 2.0V

PBIB2625E

Switch Monitor 

item

Condition

Indication

MAIN switch

MAIN SW

Pressed

ON

Released

OFF

CANCEL switch

CANCEL SW

Pressed

ON

Released

OFF

RESUME/ACCELER-
ATE switch

RESUME/ACC SW

Pressed

ON

Released

OFF

EC-462

< SERVICE INFORMATION >

[VQ35DE]

DTC P1564 ASCD STEERING SWITCH

 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 GROUND CIRCUIT FOR OPEN AND SHORT

1.

Turn ignition switch OFF.

2.

Disconnect combination switch harness connector.

3.

Disconnect ECM harness connector.

4.

Check harness continuity between combination switch terminal 15 and ECM terminal 82. 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.
• Combination switch (spiral cable)
• Harness for open and short between ECM and combination switch

>> Repair open circuit 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

SET/COAST switch

SET SW

Pressed

ON

Released

OFF

Switch Monitor 

item

Condition

Indication

Switch

Condition

Voltage [V]

MAIN switch

Pressed

Approx. 0

Released

Approx. 4.0

CANCEL switch

Pressed

Approx. 1.0

Released

Approx. 4.0

RESUME/ACCELERATE 
switch

Pressed

Approx. 3.0

Released

Approx. 4.0

SET/COAST switch

Pressed

Approx. 2.0

Released

Approx. 4.0

PBIB0311E

Continuity should exist.

Continuity should exist.

DTC P1564 ASCD STEERING SWITCH

EC-463

< SERVICE INFORMATION >

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Check the following.
• 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-463, "Component Inspection"

.

OK or NG

OK

>> GO TO 8.

NG

>> Replace ASCD steering switch.

8.

CHECK INTERMITTENT INCIDENT

Refer to 

EC-139

.

>> INSPECTION END

Component Inspection

INFOID:0000000001326326

ASCD STEERING SWITCH

1.

Disconnect combination switch (spiral cable) harness connector M203.

2.

Check continuity between combination switch (spiral cable) ter-
minals 14 and 15 with pushing each switch.

If NG, replace ASCD steering switch.

Switch

Condition

Resistance [

Ω

]

MAIN switch

Pressed

Approx. 0

Released

Approx. 4,000

CANCEL switch

Pressed

Approx. 250

Released

Approx. 4,000

RESUME/ACCELERATE 
switch

Pressed

Approx. 1,480

Released

Approx. 4,000

SET/COAST switch

Pressed

Approx. 660

Released

Approx. 4,000

PBIB1621E

EC-464

< SERVICE INFORMATION >

[VQ35DE]

DTC P1568 ICC FUNCTION

DTC P1568 ICC FUNCTION

On Board Diagnosis Logic

INFOID:0000000001326327

NOTE:
• If DTC P1568 is displayed with DTC U1000 or U1001, first perform the trouble diagnosis for DTC

U1000, U1001. Refer to 

EC-146

.

• If DTC P1568 is displayed with DTC U1010, first perform the trouble diagnosis for DTC U1010. Refer

to 

EC-148

.

• If DTC P1568 is displayed with DTC P0605, first perform the trouble diagnosis for DTC P0605. Refer

to 

EC-422

• This self-diagnosis has the one trip detection logic. 
• The MIL will not light up for this self-diagnosis. 

DTC Confirmation Procedure

INFOID:0000000001326328

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.

• 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-464, "Diagnosis Procedure"

.

Diagnosis Procedure

INFOID:0000000001326329

1.

REPLACE ICC UNIT

1.

Replace ICC unit.

2.

Perform 

ACS-11

.

3.

Check DTC of ICC unit. Refer to 

ACS-35

.

>> INSPECTION END

DTC No.

Trouble Diagnosis 

Name

DTC Detecting Condition

Possible Cause

P1568
1568

ICC function

ECM detects a difference between signals 
from ICC unit is out of specified range.

• Harness or connectors

(CAN communication line is open or shorted.)

• ICC unit
• ECM