2010 INFINITI QX56 engine

P0550 PSP SENSOREC-283
< COMPONENT DIAGNOSIS > [VK56DE]
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Component InspectionINFOID:0000000005149315
POWER STEERING PRESSURE SENSOR
1. Reconnect all harness connectors disconnected.
2. Start engine and let it idle.
3. Check voltage between ECM terminal 12 and ground under the
following conditions.
Condition Voltage
Steering wheel: Being turned. 0.5 - 4.5 V
Steering wheel: Not being turned. 0.4 - 0.8 V
MBIB0126E
Revision: April 20092010 QX56

EC-284
< COMPONENT DIAGNOSIS >[VK56DE]
P0603 ECM POWER SUPPLY
P0603 ECM POWER SUPPLY
Component DescriptionINFOID:0000000005149316
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 Diagn
osis LogicINFOID:0000000005149317
DTC Confirmation ProcedureINFOID:0000000005149318
1. If DTC Confirmation Procedure has been previously conducted, always perform the following procedure
before conducting the next step.
a. Turn ignition switch OFF and wait at least 10 seconds.
b. Turn ignition switch ON.
c. Turn ignition switch OFF and wait at least 10 seconds.
2. Start engine and let it idle for 1 second.
3. Turn ignition switch OFF, wait at least 10 seconds and then turn ON.
4. Repeat steps 1 and 2 for 4 times.
5. Check 1st trip DTC.
6. If 1st trip DTC is detected, go to EC-284, "
Diagnosis Procedure".
Diagnosis ProcedureINFOID:0000000005149319
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-III or tester.
OK or NG
OK >> GO TO 3.
NG >> GO TO 2.
2.DETECT MALFUNCTIONING PART
Check the following.
PBIB1164E
DTC No. Trouble diagnosis name DTC detecting conditionPossible cause
P0603
0603 ECM power supply circuit ECM back-up RAM system does not function
properly. • Harness or connectors
[ECM power supply (b ack-up) circuit is
open or shorted.]
•ECM
Voltage: Battery voltage
MBIB0026E
Revision: April 20092010 QX56

EC-286
< COMPONENT DIAGNOSIS >[VK56DE]
P0605 ECM
P0605 ECM
Component DescriptionINFOID:0000000005149320
The ECM consists of a microcomputer and connectors for signal
input and output and for power supply. The ECM controls the engine.
On Board Diagn
osis LogicINFOID:0000000005149321
This self-diagnosis has one or two trip detection logic.
FA I L - S A F E M O D E
ECM enters fail-safe mode when the malfunction A is detected.
DTC Confirmation ProcedureINFOID:0000000005149322
Perform PROCEDURE FOR MALFUNCTION A first. If the 1st trip DTC cannot be confirmed, perform
PROCEDURE FOR MALFUNCTION B. If there is no malfunction on PROCEDURE FOR MALFUNCTION
B, perform PROCEDURE FOR MALFUNCTION C.
NOTE:
If DTC Confirmation Procedure has been previously conducted, always perform the following procedure
before conducting the next step.
1. Turn ignition switch OFF and wait at least 10 seconds.
2. Turn ignition switch ON.
3. Turn ignition switch OFF and wait at least 10 seconds.
PROCEDURE FOR MALFUNCTION A
1. Turn ignition switch ON.
2. Check 1st trip DTC.
3. If 1st trip DTC is detected, go to EC-287, "
Diagnosis Procedure"
PROCEDURE FOR MALFUNCTION B
1. Turn ignition switch ON and wait at least 1 second.
2. Turn ignition switch OFF, wait at least 10 seconds and then turn ON.
3. Check 1st trip DTC.
4. If 1st trip DTC is detected, go to EC-287, "
Diagnosis Procedure".
PROCEDURE FOR MALFUNCTION C
1. Turn ignition switch ON and wait at least 1 second.
2. Turn ignition switch OFF, wait at least 10 seconds and then turn ON.
PBIB1164E
DTC No. Trouble diagnosis name DTC detecting conditionPossible cause
P0605
0605 Engine control module A) ECM calculation function is malfunctioning.
•ECM
B) ECM EEP-ROM system is malfunctioning.
C) ECM self shut-off function is malfunctioning.
Detected items Engine operation condition in fail-safe mode
Malfunction A • ECM stops the electric throttle control actuator control, throttle valve is maintained at a fixed opening (approx.
5 degrees) by the return spring.
• ECM deactivates ASCD operation.
Revision: April 20092010 QX56

P0643 SENSOR POWER SUPPLYEC-289
< COMPONENT DIAGNOSIS > [VK56DE]
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P0643 SENSOR POWER SUPPLY
On Board Diagnosis LogicINFOID:0000000005149328
This self-diagnosis has the on
e trip detection logic.
FA I L - S A F E M O D E
When the malfunction is detected, ECM ent ers fail-safe mode and the MIL lights up.
DTC Confirmation ProcedureINFOID:0000000005149329
NOTE:
If DTC Confirmation Procedure has been previously conducted, always perform the following procedure
before conducting the next step.
1. Turn ignition switch OFF and wait at least 10 seconds.
2. Turn ignition switch ON.
3. Turn ignition switch OFF and wait at least 10 seconds.
TESTING CONDITION:
Before performing the following procedure, confirm that battery voltage is more than 10 V at idle.
1. Start engine and let it idle for 1 second.
2. Check DTC.
3. If DTC is detected, go to EC-289, "
Diagnosis Procedure".
Diagnosis ProcedureINFOID:0000000005149330
1.CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten three ground screws on the body. Refer to EC-85, "
Ground Inspection".
OK or NG
OK >> GO TO 2.
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0643
0643 Sensor power supply circuit
short ECM 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.)
(Battery current sensor circuit is shorted.)
(Refrigerant pressure se nsor circuit is short-
ed.)
(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) b y the return
spring.
BBIA0354E
Revision: April 20092010 QX56

EC-290
< COMPONENT DIAGNOSIS >[VK56DE]
P0643 SENSOR POWER SUPPLY
NG >> Repair or replace ground connections.
2.CHECK APP SENSOR 1 POWER SUPPLY CIRCUIT
1. Disconnect accelerator pedal position (APP) sensor harness connector.
2. Turn ignition switch ON.
3. Check voltage between APP sensor terminal 7 and ground with CONSULT-III or tester.
OK or NG
OK >> GO TO 5.
NG >> GO TO 3.
3.CHECK SENSOR POWER SUPPLY CIRCUITS
Check harness for short to power and short to ground, between the following terminals
OK or NG
OK >> GO TO 4.
NG >> Repair short to ground or short to power in harness or connectors.
4.CHECK COMPONENTS
Check the following.
• EVAP control system pressure sensor (Refer to EC-248, "
Component Inspection".)
• Power steering pressure sensor (Refer to EC-283, "
Component Inspection".)
• Battery current sensor (Refer to EC-314, "
Component Inspection".)
• Refrigerant pressure sensor
OK or NG
OK >> GO TO 7.
NG >> Replace malfunctioning components.
5.CHECK ACCELERATOR PEDAL POSITION SENSOR
Refer to EC-381, "
Component Inspection".
OK or NG
OK >> GO TO 7.
NG >> GO TO 6.
BBIA0361E
Voltage: Approximately 5 V
JMBIA0601ZZ
ECM terminal Sensor terminal Reference Wiring Diagram
48 EVAP control system pressure sensor terminal 3
EC-435, "
Wiring Diagram - ENGINE
CONTROL SYSTEM -"
49Refrigerant pressure sensor terminal 1
Battery current sensor terminal 1
68 Power steering pressure sensor terminal 1
90 APP sensor terminal 7
Revision: April 20092010 QX56

EC-292
< COMPONENT DIAGNOSIS >[VK56DE]
P0850 PNP SWITCH
P0850 PNP SWITCH
Component DescriptionINFOID:0000000005149331
When the selector lever position is P or N, park/neutral position (PNP) signal from the TCM is sent to ECM.
When the gear position is P or N, transmission range switch is ON.
On Board Diagn
osis LogicINFOID:0000000005149332
DTC Confirmation ProcedureINFOID:0000000005149333
CAUTION:
Always drive vehicle at a safe speed.
NOTE:
If DTC Confirmation Procedure has been previously conducted, always perform the following procedure
before conducting the next step.
1. Turn ignition switch OFF and wait at least 10 seconds.
2. Turn ignition switch ON.
3. Turn ignition switch OFF and wait at least 10 seconds.
WITH CONSULT-III
1. Turn ignition switch ON.
2. Select “P/N POSI SW” in “DATA MONITOR” mode with CONSULT-III. Then check the “P/N POSI SW” sig-
nal under the following conditions.
If NG, go to EC-293, "
Diagnosis Procedure".
If OK, go to following step.
3. Select “DATA MONITOR” mode with CONSULT-III.
4. Start engine and warm it up to normal operating temperature.
5. Maintain the following conditions for at least 60 consecutive seconds.
6. Check 1st trip DTC.
7. If 1st trip DTC is detected, go to EC-293, "
Diagnosis Procedure".
Overall Function CheckINFOID:0000000005149334
Use this procedure to check the overall function of t he park/neutral position (PNP) signal circuit. During this
check, a 1st trip DTC might not be confirmed.
WITH GST
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0850
0850 Park/neutral position
switch The signal of the park/neutral position (PNP)
signal is not changed in the process of engine
starting and driving. • Harness or connectors
[The park/neutral position (PNP) signal
circuit is open or shorted.]
• Combination meter
•TCM
Position (Selector lever) Known-good signal
N or P position ON
Except the above position OFF
ENG SPEED1,000 - 6,375 rpm
COOLAN TEMP/S More than 70°C (158 °F)
B/FUEL SCHDL 2.0 - 31.8 msec
VHCL SPEED SE More than 64 km/h (40 MPH)
Selector lever Suitable position
Revision: April 20092010 QX56

EC-300
< COMPONENT DIAGNOSIS >[VK56DE]
P1211 TCS CONTROL UNIT
P1211 TCS CONTROL UNIT
DescriptionINFOID:0000000005149342
The malfunction information related to TCS is trans
ferred 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 Diagn osis LogicINFOID:0000000005149343
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 ProcedureINFOID:0000000005149344
TESTING CONDITION:
Before performing the following procedure, confirm that battery voltage is more than 10.5 V at idle.
1. Start engine and let it idle for at least 60 seconds.
2. Check 1st trip DTC.
3. If 1st trip DTC is detected, go to EC-300, "
Diagnosis Procedure".
Diagnosis ProcedureINFOID:0000000005149345
Go to BRC-23, "CONSULT-III Function (ABS)".
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P1211
1211 TCS control unit
ECM receives a malfunction information from
“ABS actuator electric
unit (control unit)” • ABS actuator and electric unit (control
unit)
• TCS related parts
Revision: April 20092010 QX56

P1212 TCS COMMUNICATION LINEEC-301
< COMPONENT DIAGNOSIS > [VK56DE]
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P1212 TCS COMMUNICATION LINE
DescriptionINFOID:0000000005149346
NOTE:
•
If DTC P1212 is displayed with DTC UXXXX, first perform the tr ouble diagnosis for DTC UXXXX.
• If DTC P1212 is displayed with DT C P0607, first perform the trouble diagnosis for DTC P0607. Refer
to EC-288
.
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 malf unction information such as DTC not onl y for “ABS actuator and electric unit
(control unit)” but also for ECM after TCS related repair.
On Board Diagnosis LogicINFOID:0000000005149347
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 ProcedureINFOID:0000000005149348
TESTING CONDITION:
Before performing the following procedure, confirm that battery voltage is more than 10.5 V at idle.
1. Start engine and let it idle for at least 10 seconds.
2. Check 1st trip DTC.
3. If 1st trip DTC is detected, go to EC-301, "
Diagnosis Procedure".
Diagnosis ProcedureINFOID:0000000005149349
Go to BRC-23, "CONSULT-III Function (ABS)".
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P1212
1212 TCS communication line ECM can not receive the information from
“ABS actuator and electric unit (control
unit)” continuously. • Harness or connectors
(The CAN communication line is open or short-
ed.)
• ABS actuator and electric unit (control unit)
• Dead (Weak) battery
Revision: April 20092010 QX56