2004 INFINITI QX56 Combination

EC-516Revision: August 2007
DTC P1564 ICC STEERING SWITCH
2004 QX56
7. CHECK INTERMITTENT INCIDENT
Refer to EC-127, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
>>INSPECTION END
Component InspectionUBS00HYV
ICC STEERING SWITCH
1. Disconnect combination switch (spiral cable).
2. Check continuity between combination switch (spiral cable) ter-
minals 14 and 15 with pushing each switch.
If NG, replace ICC steering switch.
Switch Condition Resistance [Ω]
ON/OFF (MAIN) switchPressed Approx. 0
Released Approx. 5,500
COAST/SET switchPressed Approx. 1,400
Released Approx. 5,500
ACCEL/RESUME switchPressed Approx. 2,600
Released Approx. 5,500
DISTANCE switchPressed Approx. 740
Released Approx. 5,500
CANCEL switchPressed Approx. 310
Released Approx. 5,500
PBIB1673E

DTC P1564 ASCD STEERING SWITCH
EC-521
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Revision: August 20072004 QX56
Diagnostic ProcedureUBS00HBD
1. CHECK ASCD STEERING SWITCH CIRCUIT
With CONSULT-II
1. Turn ignition switch ON.
2. Select “MAIN SW”, “RESUME/ACC SW”, “SET SW” and “CANCEL 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 7.
NG >> GO TO 2.
2. CHECK ASCD 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 4.
NG >> GO TO 3.
Switch Monitor item Condition Indication
ON/OFF(MAIN)
switchMAIN SWPressed ON
Released OFF
ACCEL/RESUME
switchRESUME/ACC SWPressed ON
Released OFF
COAST/SET switch SET SWPressed ON
Released OFF
CANCEL switch CANCEL SW Pressed ON
Released OFF
SEC0 06 D
Switch Condition Voltage [V]
ON/OFF(MAIN) switchPressed Approx. 0
Released Approx. 4
ACCEL/RESUME switchPressed Approx. 3
Released Approx. 4
COAST/SET switchPressed Approx. 2
Released Approx. 4
CANCEL switchPressed Approx. 1
Released Approx. 4
PBIB0 311 E
Continuity should exist.
BBIA0362E

EC-522Revision: August 2007
DTC P1564 ASCD STEERING SWITCH
2004 QX56
3. 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.
4. 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 6.
NG >> GO TO 5.
5. 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.
6. CHECK ASCD STEERING SWITCH
Refer to EC-522, "
Component Inspection" .
OK or NG
OK >> GO TO 7.
NG >> Replace ASCD steering switch.
7. CHECK INTERMITTENT INCIDENT
Refer to EC-127, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
>>INSPECTION END
Component InspectionUBS00HBE
ASCD STEERING SWITCH
1. Disconnect combination switch (spiral cable).
2. Check continuity between ASCD steering switch terminals 14
and 15 with pushing each switch.Continuity should exist.
Switch Condition Resistance [Ω]
ON/OFF(MAIN) switchPressed Approx. 0
Released Approx. 4,000
COAST/SET switchPressed Approx. 660
Released Approx. 4,000
PBIB1673E

DTC P1574 ICC VEHICLE SPEED SENSOR
EC-543
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Revision: August 20072004 QX56
Diagnostic ProcedureUBS00HZ9
1. CHECK DTC WITH TCM
Check DTC with TCM. Refer to AT - 3 9 , "
OBD-II Diagnostic Trouble Code (DTC)" .
OK or NG
OK >> GO TO 2.
NG >> Perform trouble shooting relevant to DTC indicated.
2. CHECK DTC WITH “ABS ACTUATOR AND ELECTRIC UNIT (CONTROL UNIT)”
Refer to BRC-11, "
TROUBLE DIAGNOSIS" .
OK or NG
OK >> GO TO 3.
NG >> Repair or replace.
3. CHECK DTC WITH “UNIFIED METER AND A/C AMP”
Refer to DI-5, "
COMBINATION METERS" .
>>INSPECTION END

EC-544Revision: August 2007
DTC P1574 ASCD VEHICLE SPEED SENSOR
2004 QX56
DTC P1574 ASCD VEHICLE SPEED SENSORPFP:31036
Component DescriptionUBS00HBM
The ECM receives two vehicle speed sensor signals via CAN communication line. One is sent from combina-
tion meter and the other is from TCM (Transmission control module). The ECM uses these signals for ASCD
control. Refer to EC-647, "
AUTOMATIC SPEED CONTROL DEVICE (ASCD)" for ASCD functions.
On Board Diagnosis LogicUBS00HBN
This self-diagnosis has the one trip detection logic.
The MIL will not light up for this diagnosis.
NOTE:

If DTC P1574 is displayed with DTC U1000, U1001, first perform the trouble diagnosis for DTC
U1000, U1001. Refer to EC-135, "
DTC U1000, U1001 CAN COMMUNICATION LINE" .

If DTC P1574 is displayed with DTC P0500, first perform the trouble diagnosis for DTC P0500.
Refer to EC-340, "
DTC P0500 VSS".

If DTC P1574 is displayed with DTC P0605, first perform the trouble diagnosis for DTC P0605.
Refer to EC-351, "
DTC P0605 ECM".
DTC Confirmation ProcedureUBS00HBO
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 3 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. Drive the vehicle at more than 40 km/h (25 MPH).
4. If DTC is detected, go to EC-545, "
Diagnostic Procedure" .
WITH GST
Follow the procedure “WITH CONSULT-II” above.
DTC No.Trouble Diagnosis
NameDTC Detecting Condition Possible Cause
P1574
1574ASCD vehicle speed
sensorECM detects a difference between two vehicle
speed signals is out of the specified range.

Harness or connectors
(The CAN communication line is open or
shorted.)

Combination meter

ABS actuator and electric unit (control unit)

Wheel sensor

TCM

ECM
SEF 0 58 Y

DTC P1574 ASCD VEHICLE SPEED SENSOR
EC-545
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Revision: August 20072004 QX56
Diagnostic ProcedureUBS00HBP
1. CHECK DTC WITH TCM
Check DTC with TCM. Refer to AT - 3 9 , "
OBD-II Diagnostic Trouble Code (DTC)" .
OK or NG
OK >> GO TO 2.
NG >> Perform trouble shooting relevant to DTC indicated.
2. CHECK DTC WITH ABS ACTUATOR AND ELECTRIC UNIT (CONTROL UNIT)
Refer to BRC-11, "
TROUBLE DIAGNOSIS" .
OK or NG
OK >> GO TO 3.
NG >> Repair or replace.
3. CHECK COMBINATION METER
Check combination meter function.
Refer to DI-5, "
COMBINATION METERS" .
>>INSPECTION END

EC-546Revision: August 2007
DTC P1706 PNP SWITCH
2004 QX56
DTC P1706 PNP SWITCHPFP:32006
Component DescriptionUBS00HBQ
When the gear position is P or N, park/neutral position (PNP) switch is ON.
TCM detects the position because the continuity of the line (the ON signal) exists.
Then the TCM sends the PNP switch signal to the ECM via combination meter.
CONSULT-II Reference Value in Data Monitor ModeUBS00HBR
Specification data are reference values.
On Board Diagnosis LogicUBS00HBS
DTC Confirmation ProcedureUBS00HBT
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.
WITH CONSULT-II
1. Turn ignition switch ON.
2. Select “P/N POSI SW” in “DATA MONITOR” mode with CON-
SULT-II. Then check the “P/N POSI SW” signal under the follow-
ing conditions.
If NG, go to EC-549, "
Diagnostic Procedure" .
If OK, go to following step.
3. Select “DATA MONITOR” mode with CONSULT-II.
4. Start engine and warm it up to normal operating temperature.
5. Maintain the following conditions for at least 60 consecutive sec-
onds.
6. If 1st trip DTC is detected, go to EC-549, "
Diagnostic Procedure"
.
MONITOR ITEM CONDITION SPECIFICATION
P/N POSI SW

Ignition switch: ONShift lever: P or N ON
Shift lever: Except above OFF
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P1706
1706Park/neutral position
switchThe signal of the park/neutral position (PNP)
switch is not changed in the process of engine
starting and driving.

Harness or connectors
[The park/neutral position (PNP) switch
circuit is open or shorted.]

Park/neutral position (PNP) switch

Combination meter

TCM
Position (Selector lever) Known-good signal
N or P position ON
Except the above position OFF
ENG SPEED More than 1,000 rpm
COOLAN TEMP/S More than 70°C (158°F)
B/FUEL SCHDL More than 2.0 msec
VHCL SPEED SE More than 64 km/h (40 MPH)
Selector lever Suitable position
SEF 2 12 Y
SEF 2 13 Y

DTC P1706 PNP SWITCH
EC-549
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Revision: August 20072004 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 ProcedureUBS00HBW
1. CHECK DTC WITH TCM
Refer to AT- 3 9 , "
OBD-II Diagnostic Trouble Code (DTC)" .
OK or NG
OK >> GO TO 2.
NG >> Repair or replace.
2. CHECK STARTING SYSTEM
Turn ignition switch OFF, then turn it to START.
Does starter motor operate?
Ye s o r N o
Yes >> GO TO 3.
No >> Refer to SC-10, "
STARTING SYSTEM" .
3. CHECK PNP SWITCH INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT-I
1. Turn ignition switch OFF.
2. Disconnect TCM harness connector.
3. Disconnect combination meter harness connector.
4. Check harness continuity between TCM terminal 9 and combination meter terminal 39.
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 F14, E5

Harness connectors E152, M31

Harness for open or short between TCM and combination meter
>> Repair open circuit or short to ground or short to power in harness or connectors.
TER-
MINAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
102 GR/R PNP switch[Ignition switch: ON]

Shift lever: P or NApproximately 0V
[Ignition switch: ON]

Except the above gear positionBATTERY VOLTAGE
(11 - 14V)
Continuity should exist.