ignition INFINITI QX4 2005 Factory Service Manual

DTC P1031, P1032, P1051, P1052 A/F SENSOR 1 HEATER
EC-391
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Revision: October 20052005 QX56
2. CHECK AIR FUEL RATIO (A/F) SENSOR 1 POWER SUPPLY CIRCUIT
1. Disconnect air fuel ratio (A/F) sensor 1 harness connector.
2. Turn ignition switch ON.
3. Check voltage between A/F sensor 1 terminal 3 and ground with
CONSULT-II or tester.
OK or NG
OK >> GO TO 4.
NG >> GO TO 3.
3. DETECT MALFUNCTIONING PART
Check the following.

Harness connectors E5, F14

IPDM E/R harness connector E119

10A fuse

Harness for open or short between A/F sensor 1 and fuse
>> Repair or replace harness or connectors.
4. CHECK A/F SENSOR 1 HEATER OUTPUT SIGNAL CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check harness continuity between ECM terminal 2 (bank 1) or 24 (bank 2) and A/F sensor 1 terminal 4.
Refer to Wiring Diagram.
4. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 5.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
5. CHECK A/F SENSOR 1 HEATER
Refer to EC-392, "
Component Inspection" .
OK or NG
OK >> GO TO 6.
NG >> GO TO 7.Voltage: Battery voltage
BBIA0376E
PBIB1683E
Continuity should exist.

DTC P1065 ECM POWER SUPPLY
EC-393
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Revision: October 20052005 QX56
DTC P1065 ECM POWER SUPPLYPFP:23710
Component DescriptionUBS00H79
Battery voltage is supplied to the ECM even when the ignition switch
is turned OFF for the ECM memory function of the DTC memory, the
air-fuel ratio feedback compensation value memory, the idle air vol-
ume learning value memory, etc.
On Board Diagnosis LogicUBS00H7A
DTC Confirmation ProcedureUBS00H7B
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 1 second.
2. Select “DATA MONITOR” mode with CONSULT-II.
3. Start engine and let it idle for 1 second.
4. Turn ignition switch OFF, wait at least 10 seconds and then turn
ON.
5. Repeat steps 3 and 4 for 4 times.
6. If 1st trip DTC is detected, go to EC-395, "
Diagnostic Procedure"
.
WITH GST
Follow the procedure “WITH CONSULT-II” above.
PBIB11 64 E
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P1065
1065ECM power supply circuitECM back-up RAM system does not function
properly.

Harness or connectors
[ECM power supply (back-up) circuit is
open or shorted.]

ECM
SEF 0 58 Y

DTC P1065 ECM POWER SUPPLY
EC-395
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Revision: October 20052005 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 ProcedureUBS00H7D
1. CHECK ECM POWER SUPPLY
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check voltage between ECM terminal 121 and ground with
CONSULT-II or tester.
OK or NG
OK >> GO TO 3.
NG >> GO TO 2.
2. DETECT MALFUNCTIONING PART
Check the following.

IPDM E/R connector E121

20A fuse

Harness for open or short between ECM and battery
>> Repair or replace harness or connectors.
3. CHECK INTERMITTENT INCIDENT
Refer to EC-156, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
OK or NG
OK >> GO TO 4.
NG >> Repair or replace harness or connectors.
TER-
MINAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
121 WPower supply for ECM
(Back-up)[Ignition switch: OFF]BATTERY VOLTAGE
(11 - 14V)
Voltage: Battery voltage
MBIB0026E

EC-396Revision: October 2005
DTC P1065 ECM POWER SUPPLY
2005 QX56
4. PERFORM DTC CONFIRMATION PROCEDURE
With CONSULT-II
1. Turn ignition switch ON.
2. Select “SELF DIAG RESULTS” mode with CONSULT-II.
3. Touch “ERASE”.
4.Perform DTC Confirmation Procedure.
See EC-393, "
DTC Confirmation Procedure" .
5. Is the 1st trip DTC P1065 displayed again?
With GST
1. Turn ignition switch ON.
2. Select Service $04 with GST.
3. Touch “ERASE”.
4.Perform DTC Confirmation Procedure.
See EC-393, "
DTC Confirmation Procedure" .
5. Is the 1st trip DTC P1065 displayed again?
Ye s o r N o
Yes >> GO TO 5.
No >>INSPECTION END
5. REPLACE ECM
1. Replace ECM.
2. Perform initialization of IVIS(NATS) system and registration of all IVIS(NATS) ignition key IDs. Refer to
BL-139, "
ECM Re-communicating Function" .
3. Perform EC-90, "
VIN Registration" .
4. Perform EC-90, "
Accelerator Pedal Released Position Learning" .
5. Perform EC-90, "
Throttle Valve Closed Position Learning" .
6. Perform EC-91, "
Idle Air Volume Learning" .
>>INSPECTION END

DTC P1121 ELECTRIC THROTTLE CONTROL ACTUATOR
EC-397
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Revision: October 20052005 QX56
DTC P1121 ELECTRIC THROTTLE CONTROL ACTUATORPFP:16119
Component DescriptionUBS00H7E
Electric throttle control actuator consists of throttle control motor, throttle position sensor, etc.
The throttle control motor is operated by the ECM and it opens and closes the throttle valve.
The throttle position sensor detects the throttle valve position, and the opening and closing speed of the throt-
tle valve and feeds the voltage signals to the ECM. The ECM judges the current opening angle of the throttle
valve from these signals and the ECM controls the throttle control motor to make the throttle valve opening
angle properly in response to driving condition.
On Board Diagnosis LogicUBS00H7F
This self-diagnosis has one trip detection logic.
FAIL-SAFE MODE
When the malfunction is detected, ECM enters fail-safe mode and the MIL lights up.
DTC Confirmation ProcedureUBS00H7G
NOTE:

Perform PROCEDURE FOR MALFUNCTION A AND B first. If the DTC cannot be confirmed, perform
PROCEDURE FOR MALFUNCTION C.

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 MALFUNCTION A AND B
With CONSULT-II
1. Turn ignition switch ON and wait at least 1 second.
2. Select “DATA MONITOR” mode with CONSULT-II.
3. Shift selector lever to D position and wait at least 3 seconds.
4. Shift selector lever to P position.
5. Turn ignition switch OFF and wait at least 10 seconds.
6. Turn ignition switch ON and wait at least 1 second.
7. Shift selector lever to D position and wait at least 3 seconds.
8. Shift selector lever to P position.
9. Turn ignition switch OFF, wait at least 10 seconds and then turn
ON.
10. If DTC is detected, go to EC-398, "
Diagnostic Procedure" .
With GST
Follow the procedure “With CONSULT-II” above.
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P1121
11 2 1Electric throttle control
actuatorA)Electric throttle control actuator does not func-
tion properly due to the return spring malfunc-
tion.

Electric throttle control actuator
B)Throttle valve opening angle in fail-safe mode is
not in specified range.
C) ECM detect the throttle valve is stuck open.
Detected items Engine operating condition in fail-safe mode
Malfunction AThe ECM controls the electric throttle actuator by regulating the throttle opening around the idle position.
The engine speed will not rise more than 2,000 rpm.
Malfunction B ECM controls the electric throttle control actuator by regulating the throttle opening to 20 degrees or less.
Malfunction CWhile the vehicle is driving, it slows down gradually by fuel cut. After the vehicle stops, the engine stalls.
The engine can restart in N or P position, and engine speed will not exceed 1,000 rpm or more.
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EC-398Revision: October 2005
DTC P1121 ELECTRIC THROTTLE CONTROL ACTUATOR
2005 QX56
PROCEDURE FOR MALFUNCTION C
With CONSULT-II
1. Turn ignition switch ON and wait at least 1 second.
2. Select “DATA MONITOR” mode with CONSULT-II.
3. Shift selector lever to D position and wait at least 3 seconds.
4. Shift selector lever to N, P position.
5. Start engine and let it idle for 3 seconds.
6. If DTC is detected, go to EC-398, "
Diagnostic Procedure" .
With GST
Follow the procedure “With CONSULT-II” above.
Diagnostic ProcedureUBS00H7H
1. CHECK ELECTRIC THROTTLE CONTROL ACTUATOR VISUALLY
1. Remove the intake air duct.
2. Check if a 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-90, "
Throttle Valve Closed Position Learning" .
3. Perform EC-91, "
Idle Air Volume Learning" .
>>INSPECTION END
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BBIA0364E

DTC P1122 ELECTRIC THROTTLE CONTROL FUNCTION
EC-399
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Revision: October 20052005 QX56
DTC P1122 ELECTRIC THROTTLE CONTROL FUNCTIONPFP:16119
DescriptionUBS00H7I
NOTE:
If DTC P1122 is displayed with DTC P1121 or 1126, first perform the trouble diagnosis for DTC P1121 or
P1126. Refer to EC-397, "
DTC P1121 ELECTRIC THROTTLE CONTROL ACTUATOR" or EC-405, "DTC
P1124, P1126 THROTTLE CONTROL MOTOR RELAY" .
Electric throttle control actuator consists of throttle control motor, throttle position sensor, etc.
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 LogicUBS00H7J
This self-diagnosis has the one trip detection logic.
FAIL-SAFE MODE
When the malfunction is detected, ECM enters fail-safe mode and the MIL lights up.
DTC Confirmation ProcedureUBS00H7K
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 11V when engine
is running.
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-401, "
Diagnostic Procedure" .
WITH GST
Follow the procedure “WITH CONSULT-II” above.
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P1122
11 2 2Electric throttle control
performance problemElectric throttle control function does not oper-
ate properly.

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

Electric throttle control actuator
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.
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DTC P1122 ELECTRIC THROTTLE CONTROL FUNCTION
EC-401
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Revision: October 20052005 QX56
Specification data are reference values and are measured between each terminal and ground.
Pulse signal is measured by CONSULT-II.
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.
: Average voltage for pulse signal (Actual pulse signal can be confirmed by oscilloscope.)
Diagnostic ProcedureUBS00H7M
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)
3LThrottle control motor relay
power supply[Ignition switch: ON]BATTERY VOLTAGE
(11 - 14V)
4L/WThrottle control motor
(Close)[Ignition switch: ON]

Engine: Stopped

Selector lever: D

Accelerator pedal: Released0 - 14V
5L/BThrottle control motor
(Open)[Ignition switch: ON]

Engine: Stopped

Selector lever: D

Accelerator pedal: Fully depressed0 - 14V
104 O Throttle control motor relay[Ignition switch: OFF]BATTERY VOLTAGE
(11 - 14V)
[Ignition switch: ON]0 - 1.0V
PBIB1104E
PBIB1105E
BBIA0354E

EC-402Revision: October 2005
DTC P1122 ELECTRIC THROTTLE CONTROL FUNCTION
2005 QX56
2. CHECK THROTTLE CONTROL MOTOR RELAY INPUT SIGNAL CIRCUIT-I
1. Check voltage between ECM terminal 3 and ground under the
following conditions with CONSULT-II or tester.
OK or NG
OK >> GO TO 9.
NG >> GO TO 3.
3. CHECK THROTTLE CONTROL MOTOR RELAY POWER SUPPLY CIRCUIT-I
1. Turn ignition switch OFF.
2. Check voltage between ECM terminal 104 and ground with
CONSULT-II or tester.
OK or NG
OK >> GO TO 6.
NG >> GO TO 4.
4. 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 5.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
5. CHECK FUSE
1. Disconnect 20A fuse.
2. Check 20A fuse for blown.
OK or NG
OK >> GO TO 8.
NG >> Replace 20A fuse.
Ignition switch Voltage
OFF Approximately 0V
ONBattery voltage
(11 - 14V)
MBIB0028E
Voltage: Battery voltage
PBIB11 71 E
Continuity should exist.

DTC P1122 ELECTRIC THROTTLE CONTROL FUNCTION
EC-403
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Revision: October 20052005 QX56
6. CHECK THROTTLE CONTROL MOTOR RELAY INPUT SIGNAL CIRCUIT-II
1. Disconnect ECM harness connector.
2. Disconnect IPDM E/R harness connector E119.
3. Check harness continuity between ECM terminal 3 and IPDM E/R terminal 6.
Refer to Wiring Diagram.
4. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 8.
NG >> GO TO 7.
7. DETECT MALFUNCTIONING PART
Check the following.

Harness connectors E2, F32

Harness for open or short between ECM and IPDM E/R
>> Repair open circuit or short to ground or short to power in harness or connectors.
8. CHECK INTERMITTENT INCIDENT
Refer to EC-156, "
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
65 Should exist
4 Should not exist
PBIB1480E