2004 INFINITI QX56 Electric

DTC P1122 ELECTRIC THROTTLE CONTROL FUNCTION
EC-371
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Revision: August 20072004 QX56
6. CHECK THROTTLE CONTROL MOTOR RELAY POWER SUPPLY CIRCUIT-II
1. Disconnect ECM harness connector.
2. Disconnect IPDM E/R harness connector E122.
3. Check harness continuity between ECM terminal 104 and IPDM E/R terminal 47.
Refer to Wiring Diagram.
4. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 7.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
7. CHECK FUSE
1. Disconnect 20A fuse.
2. Check 20A fuse for blown.
OK or NG
OK >> GO TO 8.
NG >> Replace 20A fuse.
8. CHECK INTERMITTENT INCIDENT
Refer to EC-127, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
OK or NG
OK >> Replace IPDM E/R. Refer to PG-17, "IPDM E/R (INTELLIGENT POWER DISTRIBUTION MOD-
ULE ENGINE ROOM)" .
NG >> Repair or replace harness or connectors.
9. CHECK THROTTLE CONTROL MOTOR OUTPUT SIGNAL CIRCUIT FOR OPEN OR SHORT
1. Turn ignition switch OFF.
2. Disconnect electric throttle control actuator harness connector.
3. Disconnect ECM harness connector.
4. Check harness continuity between the following terminals.
Refer to Wiring Diagram.
5. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 10.
NG >> Repair or replace.Continuity should exist.
Electric throttle control
actuator terminalECM terminal Continuity
55 Should not exist
4 Should exist
6 5 Should exist
4 Should not exist
PBIB1480E

EC-372Revision: August 2007
DTC P1122 ELECTRIC THROTTLE CONTROL FUNCTION
2004 QX56
10. CHECK ELECTRIC THROTTLE CONTROL ACTUATOR VISUALLY
1. Remove the intake air duct.
2. Check if foreign matter is caught between the throttle valve and
the housing.
OK or NG
OK >> GO TO 11.
NG >> Remove the foreign matter and clean the electric throttle
control actuator inside.
11 . CHECK THROTTLE CONTROL MOTOR
Refer to EC-372, "
Component Inspection" .
OK or NG
OK >> GO TO 12.
NG >> GO TO 13.
12. CHECK INTERMITTENT INCIDENT
Refer to EC-127, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
OK or NG
OK >> GO TO 13.
NG >> Repair or replace harness or connectors.
13. 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
Component InspectionUBS00H7N
THROTTLE CONTROL MOTOR
1. Disconnect electric throttle control actuator harness connector.
2. Check resistance between terminals 5 and 6.
3. If NG, replace electric throttle control actuator and go to next
step.
4. Perform EC-44, "
Throttle Valve Closed Position Learning" .
5. Perform EC-44, "
Idle Air Volume Learning" .
Remove and InstallationUBS00H7O
ELECTRIC THROTTLE CONTROL ACTUATOR
Refer to EM-15, "INTAKE MANIFOLD" .
BBIA0364E
Resistance: Approximately 1 - 15 Ω [at 25 °C (77°F)]
PBIB2066E

DTC P1124, P1126 THROTTLE CONTROL MOTOR RELAY
EC-373
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Revision: August 20072004 QX56
DTC P1124, P1126 THROTTLE CONTROL MOTOR RELAYPFP:16119
Component DescriptionUBS00H7P
Power supply for the throttle control motor is provided to the ECM via throttle control motor relay. The throttle
control motor relay is ON/OFF controlled by the ECM. When the ignition switch is turned ON, the ECM sends
an ON signal to throttle control motor relay and battery voltage is provided to the ECM. When the ignition
switch is turned OFF, the ECM sends an OFF signal to throttle control motor relay and battery voltage is not
provided to the ECM.
CONSULT-II Reference Value in Data Monitor ModeUBS00H7Q
Specification data are reference values.
On Board Diagnosis LogicUBS00H7R
These self-diagnoses have the one trip detection logic.
FAIL-SAFE MODE
When the malfunction is detected, ECM enters fail-safe mode and the MlL lights up.
DTC Confirmation ProcedureUBS00H7S
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 DTC P1124
TESTING CONDITION:
Before performing the following procedure, confirm that battery voltage is more than 8V when engine
is running.
With CONSULT-II
1. Turn ignition switch ON and wait at least 1 second.
2. Select “DATA MONITOR” mode with CONSULT-II.
3. If DTC is detected, go to EC-376, "
Diagnostic Procedure" .
With GST
Follow the procedure “With CONSULT-II” above.
MONITOR ITEM CONDITION SPECIFICATION
THRTL RELAY

Ignition switch: ON ON
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P1124
11 2 4Throttle control motor
relay circuit shortECM detect the throttle control motor
relay is stuck ON.

Harness or connectors
(Throttle control motor relay circuit is shorted)

Throttle control motor relay
P1126
11 2 6Throttle control motor
relay circuit openECM detects a voltage of power source
for throttle control motor is excessively
low.

Harness or connectors
(Throttle control motor relay circuit is open)

Throttle control motor relay
Engine operating 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-378Revision: August 2007
DTC P1128 THROTTLE CONTROL MOTOR
2004 QX56
DTC P1128 THROTTLE CONTROL MOTORPFP:16119
Component DescriptionUBS00H7V
The throttle control motor is operated by the ECM and it opens and closes the throttle valve.
The current opening angle of the throttle valve is detected by the throttle position sensor and it provides feed-
back to the ECM to control the throttle control motor to make the throttle valve opening angle properly in
response to driving condition.
On Board Diagnosis LogicUBS00H7W
This self-diagnosis has the one trip detection logic.
FAIL -S AFE M OD E
When the malfunction is detected, the ECM enters fail-safe mode and the MIL lights up.
DTC Confirmation ProcedureUBS00H7X
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 and wait at least 2 seconds.
2. Select “DATA MONITOR” mode with CONSULT-II.
3. Start engine and let it idle for 5 seconds.
4. If DTC is detected, go to EC-380, "
Diagnostic Procedure" .
WITH GST
Follow the procedure “WITH CONSULT-II” above.
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P1128
11 2 8Throttle control motor
circuit shortECM detects short in both circuits between
ECM and throttle control motor.

Harness or connectors
(Throttle control motor circuit is shorted.)

Electric throttle control actuator
(Throttle control motor)
Engine operating 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

DTC P1128 THROTTLE CONTROL MOTOR
EC-381
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Revision: August 20072004 QX56
2. CHECK THROTTLE CONTROL MOTOR OUTPUT SIGNAL CIRCUIT FOR OPEN OR SHORT
1. Disconnect electric throttle control actuator harness connector.
2. Disconnect ECM harness connector.
3. Check harness continuity between the following terminals.
Refer to Wiring Diagram.
4. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 3.
NG >> Repair or replace.
3. CHECK THROTTLE CONTROL MOTOR
Refer to EC-381, "
Component Inspection" .
OK or NG
OK >> GO TO 4.
NG >> GO TO 5.
4. CHECK INTERMITTENT INCIDENT
Refer to EC-127, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
OK or NG
OK >> GO TO 5.
NG >> Repair or replace harness or connectors.
5. 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
Component InspectionUBS00H80
THROTTLE CONTROL MOTOR
1. Disconnect electric throttle control actuator harness connector.
2. Check resistance between terminals 5 and 6.
3. If NG, replace electric throttle control actuator and go to next
step.
4. Perform EC-44, "
Throttle Valve Closed Position Learning" .
5. Perform EC-44, "
Idle Air Volume Learning" .
Electric throttle control
actuator terminalECM terminal Continuity
55 Should not exist
4 Should exist
65 Should exist
4 Should not exist
BBIA0371E
Resistance: Approximately 1 - 15 Ω [at 25 °C (77°F)]
PBIB2066E

EC-382Revision: August 2007
DTC P1128 THROTTLE CONTROL MOTOR
2004 QX56
Removal and InstallationUBS00H81
ELECTRIC THROTTLE CONTROL ACTUATOR
Refer to EM-15, "INTAKE MANIFOLD" .

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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