2005 INFINITI QX4 air condition

EC-380Revision: October 2005
DTC P0550 PSP SENSOR
2005 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 ProcedureUBS00H6U
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)
12 RPower steering pressure
sensor[Engine is running]

Steering wheel: Being turned.0.5 - 4.5V
[Engine is running]

Steering wheel: Not being turned.0.4 - 0.8V
67 B Sensor ground[Engine is running]

Warm-up condition

Idle speedApproximately 0V
68 W/LSensor power supply
(Power steering pressure
sensor)[Ignition switch: ON]Approximately 5V
BBIA0354E

EC-386Revision: October 2005
DTC P1031, P1032, P1051, P1052 A/F SENSOR 1 HEATER
2005 QX56
DTC P1031, P1032, P1051, P1052 A/F SENSOR 1 HEATERPFP:22693
DescriptionUBS00H71
SYSTEM DESCRIPTION
The ECM performs ON/OFF duty control of the A/F sensor 1 heater corresponding to the engine operating
condition to keep the temperature of A/F sensor 1 element at the specified range.
CONSULT-II Reference Value in Data Monitor ModeUBS00H72
Specification data are reference values.
On Board Diagnosis LogicUBS00H73
DTC Confirmation ProcedureUBS00H74
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 between 10.5V and 16V at
idle.
WITH CONSULT-II
1. Turn ignition switch ON and select “DATA MONITOR” mode with
CONSULT-II.
2. Start engine and let it idle for at least 10 seconds.
3. If 1st trip DTC is detected, go to EC-390, "
Diagnostic Procedure"
.
WITH GST
Follow the procedure “WITH CONSULT-II” above.
Sensor Input Signal to ECM ECM function Actuator
Camshaft position sensor (PHASE)
Crankshaft position sensor (POS)Engine speed
Air fuel ratio (A/F) sensor 1
heater controlAir fuel ratio (A/F) sensor 1
heater
Mass air flow sensor Amount of intake air
MONITOR ITEM CONDITION SPECIFICATION
A/F S1 HTR (B1)
A/F S1 HTR (B2)

Engine: After warming up, idle the engine 0 - 100%
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P1031
1031
(Bank 1)Air fuel ratio (A/F) sensor
1 heater control circuit
lowThe current amperage in the heated air fuel ratio
(A/F) sensor 1 heater circuit is out of the normal
range.
(An excessively low voltage signal is sent to ECM
through the heated air fuel ratio (A/F) sensor 1
heater.)

Harness or connectors
(The A/F sensor 1 heater circuit is
open or shorted.)

A/F sensor 1 heater P1051
1051
(Bank 2)
P1032
1032
(Bank 1)Air fuel ratio (A/F) sensor
1 heater control circuit
highThe current amperage in the heated air fuel ratio
(A/F) sensor 1 heater circuit is out of the normal
range.
(An excessively high voltage signal is sent to ECM
through the heated air fuel ratio (A/F) sensor 1
heater.)

Harness or connectors
(The A/F sensor 1 heater circuit is
shorted.)

A/F sensor 1 heater P1052
1052
(Bank 2)
SEF 0 58 Y

EC-390Revision: October 2005
DTC P1031, P1032, P1051, P1052 A/F SENSOR 1 HEATER
2005 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 ProcedureUBS00H76
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)
24 BR/WA/F sensor 1 heater
(bank 2)[Engine is running]

Warm-up condition

Idle speedApproximately 5V
PBIB1584E
BBIA0354E

DTC P1065 ECM POWER SUPPLY
EC-393
C
D
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MA
EC
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
C
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MA
EC
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

DTC P1122 ELECTRIC THROTTLE CONTROL FUNCTION
EC-401
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MA
EC
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.

EC-408Revision: October 2005
DTC P1124, P1126 THROTTLE CONTROL MOTOR RELAY
2005 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 ProcedureUBS00H7U
1. 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 4.
NG >> GO TO 2.
2. CHECK THROTTLE CONTROL MOTOR RELAY POWER SUPPLY CIRCUIT-II
1. Disconnect ECM harness connector.
2. Disconnect IPDM E/R harness connector E122.
3. Check 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 3.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
3. CHECK FUSE
1. Disconnect 20A fuse.
2. Check 20A fuse for blown.
OK or NG
OK >> GO TO 7.
NG >> Replace 20A fuse.
TER-
MINAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
3LThrottle control motor relay
power supply[Ignition switch: ON]BATTERY VOLTAGE
(11 - 14V)
104 O Throttle control motor relay[Ignition switch: OFF]BATTERY VOLTAGE
(11 - 14V)
[Ignition switch: ON]0 - 1.0V
Voltage: Battery voltage
PBIB11 71 E
Continuity should exist.