Electric INFINITI QX56 2004 Factory Service Manual

EC-408Revision: August 2007
DTC P1211 TCS CONTROL UNIT
2004 QX56
DTC P1211 TCS CONTROL UNITPFP:47850
DescriptionUBS00H8L
The malfunction information related to TCS is transferred through the CAN communication line from “ABS
actuator and electric unit (control unit)” to ECM.
Be sure to erase the malfunction information such as DTC not only for “ABS actuator and electric unit
(control unit)” but also for ECM after TCS related repair.
On Board Diagnosis LogicUBS00H8M
Freeze frame data is not stored in the ECM for this self-diagnosis.
The MIL will not light up for this self-diagnosis.
DTC Confirmation ProcedureUBS00H8N
TESTING CONDITION:
Before performing the following procedure, confirm that battery voltage is more than 10.5V at idle.
WITH CONSULT-II
1. Turn ignition switch ON.
2. Select “DATA MONITOR” mode with CONSULT-II.
3. Start engine and let it idle for at least 60 seconds.
4. If 1st trip DTC is detected, go to EC-408, "
Diagnostic Procedure"
.
WITH GST
Follow the procedure “WITH CONSULT-II” above.
Diagnostic ProcedureUBS00H8O
Go to BRC-11, "TROUBLE DIAGNOSIS" .
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P1211
1211TCS control unitECM receives a malfunction information from
“ABS actuator electric unit (control unit)”

ABS actuator and electric unit (control
unit)

TCS related parts
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DTC P1212 TCS COMMUNICATION LINE
EC-409
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Revision: August 20072004 QX56
DTC P1212 TCS COMMUNICATION LINEPFP:47850
DescriptionUBS00H8P
NOTE:
If DTC P1212 is displayed with DTC U1000 or U1001, first perform the trouble diagnosis for DTC U1000,
U1001. Refer to EC-135, "
DTC U1000, U1001 CAN COMMUNICATION LINE" .
This CAN communication line is used to control the smooth engine operation during the TCS operation. Pulse
signals are exchanged between ECM and “ABS actuator and electric unit (control unit)”.
Be sure to erase the malfunction information such as DTC not only for “ABS actuator and electric unit
(control unit)” but also for ECM after TCS related repair.
On Board Diagnosis LogicUBS00H8Q
Freeze frame data is not stored in the ECM for this self-diagnosis.
The MIL will not light up for this self-diagnosis.
DTC Confirmation ProcedureUBS00H8R
TESTING CONDITION:
Before performing the following procedure, confirm that battery voltage is more than 10.5V at idle.
WITH CONSULT-II
1. Turn ignition switch ON.
2. Select “DATA MONITOR” mode with CONSULT-II.
3. Start engine and let it idle for at least 10 seconds.
4. If a 1st trip DTC is detected, go to EC-409, "
Diagnostic Proce-
dure" .
WITH GST
Follow the procedure “WITH CONSULT-II” above.
Diagnostic ProcedureUBS00H8S
1. CHECK ABS ACTUATOR AND ELECTRIC UNIT (CONTROL UNIT) FUNCTION
Refer to BRC-11, "
TROUBLE DIAGNOSIS" .
>>INSPECTION END
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P1212
1212TCS communication
lineECM can not receive the information
from “ABS actuator and electric unit (con-
trol unit)” continuously.

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

ABS actuator and electric unit (control unit)

Dead (Weak) battery
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EC-420Revision: August 2007
DTC P1225 TP SENSOR
2004 QX56
DTC P1225 TP SENSORPFP:16119
Component DescriptionUBS00H91
Electric throttle control actuator consists of throttle control motor,
throttle position sensor, etc. The throttle position sensor responds to
the throttle valve movement.
The throttle position sensor has the two sensors. These sensors are
a kind of potentiometers which transform the throttle valve position
into output voltage, and emit the voltage signal to the ECM. In addi-
tion, these sensors detect the opening and closing speed of the
throttle valve and feed the voltage signals to the ECM. The ECM
judges the current opening angle of the throttle valve from these sig-
nals and the ECM controls the throttle control motor to make the
throttle valve opening angle properly in response to driving condi-
tion.
On Board Diagnosis LogicUBS00H92
The MIL will not light up for this diagnosis.
DTC Confirmation ProcedureUBS00H93
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:
Before performing the following procedure, confirm that battery voltage is more than 10V at idle.
WITH CONSULT-II
1. Turn ignition switch ON.
2. Select “DATA MONITOR” mode with CONSULT-II.
3. Turn ignition switch OFF and wait at least 10 seconds.
4. Turn ignition switch ON.
5. If 1st trip DTC is detected, go to EC-421, "
Diagnostic Procedure"
.
WITH GST
Follow the procedure “WITH CONSULT-II” above.
PBIB0145E
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P1225
1225Closed throttle position learning
performance problemClosed throttle position learning value is
excessively low.

Electric throttle control actuator
(TP sensor 1 and 2)
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DTC P1225 TP SENSOR
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Revision: August 20072004 QX56
Diagnostic ProcedureUBS00H94
1. CHECK ELECTRIC THROTTLE CONTROL ACTUATOR VISUALLY
1. Turn ignition switch OFF.
2. Remove the intake air duct.
3. Check if foreign matter is caught between the throttle valve and
the housing.
OK or NG
OK >> GO TO 2.
NG >> Remove the foreign matter and clean the electric throttle
control actuator inside.
2. REPLACE ELECTRIC THROTTLE CONTROL ACTUATOR
1. Replace the electric throttle control actuator.
2. Perform EC-44, "
Throttle Valve Closed Position Learning" .
3. Perform EC-44, "
Idle Air Volume Learning" .
>>INSPECTION END
Removal and InstallationUBS00H95
ELECTRIC THROTTLE CONTROL ACTUATOR
Refer to EM-15, "INTAKE MANIFOLD" .
BBIA0364E

EC-422Revision: August 2007
DTC P1226 TP SENSOR
2004 QX56
DTC P1226 TP SENSORPFP:16119
Component DescriptionUBS00H96
Electric throttle control actuator consists of throttle control motor,
throttle position sensor, etc. The throttle position sensor responds to
the throttle valve movement.
The throttle position sensor has the two sensors. These sensors are
a kind of potentiometers which transform the throttle valve position
into output voltage, and emit the voltage signal to the ECM. In addi-
tion, these sensors detect the opening and closing speed of the
throttle valve and feed the voltage signals to the ECM. The ECM
judges the current opening angle of the throttle valve from these sig-
nals and the ECM controls the throttle control motor to make the
throttle valve opening angle properly in response to driving condi-
tion.
On Board Diagnosis LogicUBS00H97
The MIL will not light up for this diagnosis.
DTC Confirmation ProcedureUBS00H98
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:
Before performing the following procedure, confirm that battery voltage is more than 10V at idle.
WITH CONSULT-II
1. Turn ignition switch ON.
2. Select “DATA MONITOR” mode with CONSULT-II.
3. Turn ignition switch OFF and wait at least 10 seconds.
4. Turn ignition switch ON.
5. Repeat steps 3 and 4 for 32 times.
6. If 1st trip DTC is detected, go to EC-423, "
Diagnostic Procedure"
.
WITH GST
Follow the procedure “WITH CONSULT-II” above.
PBIB0145E
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P1226
1226Closed throttle position learning
performance problemClosed throttle position learning is not performed
successfully, repeatedly.

Electric throttle control actuator
(TP sensor 1 and 2)
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DTC P1226 TP SENSOR
EC-423
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Revision: August 20072004 QX56
Diagnostic ProcedureUBS00H99
1. CHECK ELECTRIC THROTTLE CONTROL ACTUATOR VISUALLY
1. Turn ignition switch OFF.
2. Remove the intake air duct.
3. Check if foreign matter is caught between the throttle valve and
the housing.
OK or NG
OK >> GO TO 2.
NG >> Remove the foreign matter and clean the electric throttle
control actuator inside.
2. REPLACE ELECTRIC THROTTLE CONTROL ACTUATOR
1. Replace the electric throttle control actuator.
2. Perform EC-44, "
Throttle Valve Closed Position Learning" .
3. Perform EC-44, "
Idle Air Volume Learning" .
>>INSPECTION END
Removal and InstallationUBS00H9A
ELECTRIC THROTTLE CONTROL ACTUATOR
Refer to EM-15, "INTAKE MANIFOLD" .
BBIA0364E

EC-424Revision: August 2007
DTC P1229 SENSOR POWER SUPPLY
2004 QX56
DTC P1229 SENSOR POWER SUPPLYPFP:16119
On Board Diagnosis LogicUBS00H9B
This self-diagnosis has the one trip detection logic.
FAIL -S AFE M OD E
When the malfunction is detected, ECM enters fail-safe mode and the MIL lights up.
DTC Confirmation ProcedureUBS00H9C
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:
Before performing the following procedure, confirm that battery voltage is more than 10V at idle.
WITH CONSULT-II
1. Turn ignition switch ON.
2. Select “DATA MONITOR” mode with CONSULT-II.
3. Start engine and let it idle for 1 second.
4. If DTC is detected, go to EC-426, "
Diagnostic Procedure" .
WITH GST
Follow the procedure “WITH CONSULT-II” above.
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P1229
1229Sensor power supply circuit
shortECM detects a voltage of power source
for sensor is excessively low or high.

Harness or connectors
(APP sensor 1 circuit is shorted.)
(PSP sensor circuit is shorted.)
(Refrigerant pressure sensor circuit is
shorted.)
(EVAP control system pressure sensor circuit
is shorted.)

Accelerator pedal position sensor

Power steering pressure sensor

Refrigerant pressure sensor

EVAP control system pressure sensor
Engine operation condition in fail-safe mode
ECM stops the electric throttle control actuator control, throttle valve is maintained at a fixed opening (approx. 5 degrees) by the return
spring.
SEF 0 58 Y

EC-510Revision: August 2007
DTC P1564 ICC STEERING SWITCH
2004 QX56
DTC P1564 ICC STEERING SWITCHPFP:25551
Component DescriptionUBS00HYP
ICC 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 ACS-6, "
DESCRIPTION" for the ICC function.
CONSULT-II Reference Value in Data Monitor ModeUBS00HYQ
Specification data are reference values.
On Board Diagnosis LogicUBS00HYR

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 perform the trouble diagnosis for DTC P0605. Refer to
EC-351, "
DTC P0605 ECM" .
DTC Confirmation ProcedureUBS00HYS
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.
BBIA0469E
MONITOR ITEM CONDITION SPECIFICATION
MAIN SW

Ignition switch: ON
ON/OFF (MAIN) switch: Pressed ON

ON/OFF (MAIN) switch: Released OFF
CANCEL SW

Ignition switch: ON
CANCEL switch: Pressed ON

CANCEL switch: Released OFF
RESUME/ACC SW

Ignition switch: ON
ACCEL/RESUME switch: Pressed ON

ACCEL/RESUME switch: Released OFF
SET SW

Ignition switch: ON
COAST/SET switch: Pressed ON

COAST/SET switch: Released OFF
DIST SW

Ignition switch: ON
DISTANCE switch: Pressed ON

DISTANCE switch: Released OFF
DTC No.Trouble Diagnosis
NameDTC Detecting Condition Possible Cause
P1564
1564ICC steering switch

An excessively high voltage signal from the
ICC steering switch is sent to ECM.

ECM detects that input signal from the ICC
steering switch is out of the specified range.

ECM detects that the ICC steering switch is
stuck ON.

Harness or connectors
(The switch circuit is open or shorted.)

ICC steering switch

ECM

DTC P1564 ASCD STEERING SWITCH
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Revision: August 20072004 QX56
DTC P1564 ASCD STEERING SWITCHPFP:25551
Component DescriptionUBS00HB8
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-647, "
AUTOMATIC SPEED CONTROL DEVICE
(ASCD)" for the ASCD function.
CONSULT-II Reference Value in Data Monitor ModeUBS00HB9
Specification data are reference values.
On Board Diagnosis LogicUBS00HBA
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-351, "
DTC P0605 ECM" .
BBIA0362E
MONITOR ITEM CONDITION SPECIFICATION
MAIN SW

Ignition switch: ONON/OFF(MAIN) switch: Pressed ON
ON/OFF(MAIN) switch: Released OFF
CANCEL SW

Ignition switch: ONCANCEL switch: Pressed ON
CANCEL switch: Released OFF
RESUME/ACC SW

Ignition switch: ONACCEL/RESUME switch: Pressed ON
ACCEL/RESUME switch: Released OFF
SET SW

Ignition switch: ONCOAST/SET switch: Pressed ON
COAST/SET 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

ECM

EC-542Revision: August 2007
DTC P1574 ICC VEHICLE SPEED SENSOR
2004 QX56
DTC P1574 ICC VEHICLE SPEED SENSORPFP:31036
Component DescriptionUBS00HZ6
The ECM receives two vehicle speed signals via CAN communication line. One is sent from “unified meter and
A/C amp.”, and the other is from TCM (Transmission control module). The ECM uses these signals for ICC
control. Refer to ACS-6, "
DESCRIPTION" for ICC functions.
On Board Diagnosis LogicUBS00HZ7

This self-diagnosis has the one trip detection logic.

The MIL will not light up for this self-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 ProcedureUBS00HZ8
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.
2. Select “DATA MONITOR” mode with CONSULT-II.
3. Drive the vehicle at more than 40 km/h (25MPH).
4. If DTC is detected, go to EC-543, "
Diagnostic Procedure" .
WITH GST
Follow the procedure “WITH CONSULT-II” above.
DTC No. Trouble Diagnosis Name DTC Detecting Condition Possible Cause
P1574
1574ICC 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.)

Unified meter and A/C amp.

ABS actuator and electric unit (control unit)

Wheel sensor

TCM

ECM
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