Page 1649 of 3383

EC-438Revision: November 2009
DTC P0461 FUEL LEVEL SENSOR
2006 QX56
DTC P0461 FUEL LEVEL SENSORPFP:25060
Component DescriptionUBS00H62
The fuel level sensor is mounted in the fuel level sensor unit. The
sensor detects a fuel level in the fuel tank and transmits a signal to
the combination meter. The combination meter sends the fuel level
sensor signal to the ECM through CAN communication line.
It consists of two parts, one is mechanical float and the other is vari-
able resistor. Fuel level sensor output voltage changes depending on
the movement of the fuel mechanical float.
On Board Diagnosis LogicUBS00H63
NOTE:
If DTC P0461 is displayed with DTC U1000 or U1001, first perform the trouble diagnosis for DTC
U1000, U1001. Refer to EC-151, "
DTC U1000, U1001 CAN COMMUNICATION LINE" .
If DTC P0461 is displayed with DTC U1010, first perform the trouble diagnosis for DTC U1010.
Refer to EC-154, "
DTC U1010 CAN COMMUNICATION" .
Driving long distances naturally affect fuel gauge level.
This diagnosis detects the fuel gauge malfunction of the gauge not moving even after a long distance has
been driven.
Overall Function CheckUBS00H64
Use this procedure to check the overall function of the fuel level sensor function. During this check, a 1st trip
DTC might not be confirmed.
WARNING:
When performing following procedure, be sure to observe the handling of the fuel. Refer to FL-10,
"FUEL TANK" .
TESTING CONDITION:
Before starting overall function check, preparation of draining fuel and refilling fuel is required.
WITH CONSULT-II
NOTE:
Start from step 10, if it is possible to confirm that the fuel cannot be drained by 30 (7-7/8 US gal, 6-5/
8 Imp gal) in advance.
1. Prepare a fuel container and a spare hose.
2. Release fuel pressure from fuel line, refer to EC-80, "
FUEL PRESSURE RELEASE" .
3. Remove the fuel feed hose on the fuel level sensor unit.
4. Connect a spare fuel hose where the fuel feed hose was removed.
5. Turn ignition switch OFF and wait at least 10 seconds then turn ON.
BBIA0402E
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0461
0461 Fuel level sensor circuit
range/performance The output signal of the fuel level sensor
does not change within the specified range
even though the vehicle has been driven a
long distance.
Harness or connectors
(The CAN communication line is open or
shorted)
Harness or connectors
(The sensor circuit is open or shorted)
Combination meter
Fuel level sensor
Page 1650 of 3383

DTC P0461 FUEL LEVEL SENSOREC-439
C
DE
F
G H
I
J
K L
M A
EC
Revision: November 2009 2006 QX56
6. Select “FUEL LEVEL SE ” in “DATA MONITOR” mode with CON-
SULT-II.
7. Check “FUEL LEVEL SE ” output voltage and note it.
8. Select “FUEL PUMP ” in “ACTIVE TEST ” mode with CONSULT-
II.
9. Touch “ON” and drain fuel approximately 30 (7-7/8 US gal, 6-
5/8 Imp gal) and stop it.
10. Check “FUEL LEVEL SE ” output voltage and note it.
11. Fill fuel into the fuel tank for 30 (7-7/8 US gal, 6-5/8 Imp gal).
12. Check “FUEL LEVEL SE ” output voltage and note it.
13. Confirm whether the voltage changes more than 0.03V during step 7 to 10 and 10 to 12. If NG, go to EC-439, "
Diagnostic Procedure" .
WITH GST
NOTE:
Start from step 8, if it is possible to confirm that the fuel cannot be drained by 30 (7-7/8 US gal, 6-5/8
Imp gal) in advance.
1. Prepare a fuel container and a spare hose.
2. Release fuel pressure from fuel line. Refer to EC-80, "
FUEL PRESSURE RELEASE" .
3. Remove the fuel feed hose on the fuel level sensor unit.
4. Connect a spare fuel hose where the fuel feed hose was removed.
5. Turn ignition switch ON.
6. Drain fuel by 30 (7-7/8 US gal, 6-5/8 Imp gal) from the fuel tank using proper equipment.
7. Confirm that the fuel gauge indication varies.
8. Fill fuel into the fuel tank for 30 (7-7/8 US gal, 6-5/8 Imp gal).
9. Confirm that the fuel gauge indication varies.
10. If NG, go to EC-439, "
Diagnostic Procedure" .
Diagnostic ProcedureUBS00H65
1. CHECK COMBINATION METER FUNCTION
Refer to DI-5, "
COMBINATION METERS" .
OK or NG
OK >> GO TO 2.
NG >> Go to DI-22, "
Fuel Level Sensor Unit Inspection" .
2. CHECK INTERMITTENT INCIDENT
Refer to EC-144, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
>> INSPECTION END
Removal and InstallationUBS00H66
FUEL LEVEL SENSOR
Refer to FL-6, "FUEL LEVEL SENSOR UNIT, FUEL FILTER AND FUEL PUMP ASSEMBLY" .
SEF195Y
Page 1651 of 3383

EC-440Revision: November 2009
DTC P0462, P0463 FUEL LEVEL SENSOR CIRCUIT
2006 QX56
DTC P0462, P0463 FUEL LEVEL SENSOR CIRCUITPFP:25060
Component DescriptionUBS00H67
The fuel level sensor is mounted in the fuel level sensor unit. The
sensor detects a fuel level in the fuel tank and transmits a signal to
the combination meter. The combination meter sends the fuel level
sensor signal to the ECM through CAN communication line.
It consists of two parts, one is mechanical float and the other is vari-
able resistor. Fuel level sensor output voltage changes depending on
the movement of the fuel mechanical float.
On Board Diagnosis LogicUBS00H68
NOTE:
If DTC P0462 or P0463 is displayed with DTC U1000 or U1001, first perform the trouble diagnosis
for DTC U1000, U1001. Refer to EC-151, "
DTC U1000, U1001 CAN COMMUNICATION LINE" .
If DTC P0462 or P0463 is displayed with DTC U1010, first perform the trouble diagnosis for DTC
U1010. Refer to EC-154, "
DTC U1010 CAN COMMUNICATION" .
This diagnosis indicates the former, to detect open or short circuit malfunction.
DTC Confirmation ProcedureUBS00H69
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 at ignition
switch ON.
WITH CONSULT-II
1. Turn ignition switch ON.
2. Select “DATA MONITOR ” mode with CONSULT-II.
3. Wait at least 5 seconds.
4. If 1st trip DTC is detected, go to EC-441, "
Diagnostic Procedure"
.
WITH GST
Follow the procedure “WITH CONSULT-II” above.
BBIA0402E
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0462
0462 Fuel level sensor circuit
low input An excessively low voltage from the sensor is
sent to ECM.
Harness or connectors
(The CAN communication line is open or
shorted)
Harness or connectors
(The sensor circuit is open or shorted)
Combination meter
Fuel level sensor
P0463
0463
Fuel level sensor circuit
high input An excessively high voltage from the sensor is
sent to ECM.
SEF195Y
Page 1652 of 3383
DTC P0462, P0463 FUEL LEVEL SENSOR CIRCUITEC-441
C
DE
F
G H
I
J
K L
M A
EC
Revision: November 2009 2006 QX56
Diagnostic ProcedureUBS00H6A
1. CHECK COMBINATION METER FUNCTION
Refer to DI-5, "
COMBINATION METERS" .
OK or NG
OK >> GO TO 2.
NG >> Go to DI-22, "
Fuel Level Sensor Unit Inspection" .
2. CHECK INTERMITTENT INCIDENT
Refer to EC-144, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
>> INSPECTION END
Removal and InstallationUBS00H6B
FUEL LEVEL SENSOR
Refer to FL-6, "FUEL LEVEL SENSOR UNIT, FUEL FILTER AND FUEL PUMP ASSEMBLY" .
Page 1653 of 3383

EC-442Revision: November 2009
DTC P0500 VSS
2006 QX56
DTC P0500 VSSPFP:32702
DescriptionUBS00H6C
NOTE:
If DTC P0500 is displayed with DTC U1000 or U1001, first perform the trouble diagnosis for DTC
U1000, U1001. Refer to EC-151, "
DTC U1000, U1001 CAN COMMUNICATION LINE" .
If DTC P0500 is displayed with DTC U1010, first perform the trouble diagnosis for DTC U1010.
Refer to EC-154, "
DTC U1010 CAN COMMUNICATION" .
The vehicle speed signal is sent to the combination meter from the “ABS actuator and electric unit (control
unit) ” by CAN communication line. The c combination meter then sends a signal to the ECM by CAN commu-
nication line.
On Board Diagnosis LogicUBS00H6D
DTC Confirmation ProcedureUBS00H6E
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:
Steps 1 and 2 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 (VDC switch OFF).
2. Read “VHCL SPEED SE ” in “DATA MONITOR ” mode with CONSULT-II. The vehicle speed on CONSULT-
II should exceed 10 km/h (6 MPH) when rotating wheels with suitable gear position.
If NG, go to EC-443, "
Diagnostic Procedure" .
If OK, go to following step.
3. Select “DATA MONITOR ” mode with CONSULT-II.
4. Warm engine up to normal operating temperature.
5. Maintain the following conditions for at least 60 consecutive sec- onds.
6. If 1st trip DTC is detected, go to EC-443, "
Diagnostic Procedure"
.
Overall Function CheckUBS00H6F
Use this procedure to check the overall function of the vehicle speed sensor circuit. During this check, a 1st
trip DTC might not be confirmed.
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0500
0500 Vehicle speed sensor The almost 0 km/h (0 MPH) signal from
vehicle speed sensor is sent to ECM
even when vehicle is being driven.
Harness or connectors
(The CAN communication line is open or
shorted)
Harness or connectors
(The vehicle speed signal circuit is open or
shorted)
Wheel sensor
Combination meter
ABS actuator and electric unit (control unit)
ENG SPEED
More than 1,600 rpm
COOLAN TEMP/S More than 70°C (158°F)
B/FUEL SCHDL More than 6.9 msec
Selector lever Except P or N position
PW/ST SIGNAL OFF
SEF196Y
Page 1654 of 3383
DTC P0500 VSSEC-443
C
DE
F
G H
I
J
K L
M A
EC
Revision: November 2009 2006 QX56
WITH GST
1. Lift up drive wheels.
2. Start engine.
3. Read vehicle speed sensor signal in Service $01 with GST.
The vehicle speed sensor on GST should be able to exceed 10 km/h (6 MPH) when rotating wheels with
suitable gear position.
4. If NG, go to EC-443, "
Diagnostic Procedure" .
Diagnostic ProcedureUBS00H6G
1. CHECK DTC WITH ABS ACTUATOR AND ELECTRIC UNIT (CONTROL UNIT)
Refer to BRC-11, "
TROUBLE DIAGNOSIS" .
OK or NG
OK >> GO TO 2.
NG >> Repair or replace.
2. CHECK COMBINATION METER FUNCTION
Refer to DI-5, "
COMBINATION METERS" .
>> INSPECTION END
Page 1655 of 3383

EC-444Revision: November 2009
DTC P0506 ISC SYSTEM
2006 QX56
DTC P0506 ISC SYSTEMPFP:23781
DescriptionUBS00H6H
NOTE:
If DTC P0506 is displayed with other DTC, first perform the trouble diagnosis for the other DTC.
The ECM controls the engine idle speed to a specified level through the fine adjustment of the air, which is let
into the intake manifold, by operating the electric throttle control actuator. The operating of the throttle valve is
varied to allow for optimum control of the engine idling speed. The crankshaft position sensor (POS) detects
the actual engine speed and sends a signal to the ECM.
The ECM controls the electric throttle control actuator so that the engine speed coincides with the target value
memorized in the ECM. The target engine speed is the lowest speed at which the engine can operate steadily.
The optimum value stored in the ECM is determined by taking into consideration various engine conditions,
such as during warming up, deceleration, and engine load (air conditioner, power steering and cooling fan
operation, etc.).
On Board Diagnosis LogicUBS00H6I
DTC Confirmation ProcedureUBS00H6J
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.
If the target idle speed is out of the specified value, perform EC-78, "Idle Air Volume Learning" ,
before conducting DTC Confirmation Procedure. For the target idle speed, refer to the EC-637,
"SERVICE DATA AND SPECIFICATIONS (SDS)" .
TESTING CONDITION:
Before performing the following procedure, confirm that battery voltage is more than 11V at idle.
Always perform the test at a temperature above −10 °C (14 °F).
WITH CONSULT-II
1. Open engine hood.
2. Start engine and warm it up to normal operating temperature.
3. Turn ignition switch OFF and wait at least 10 seconds.
4. Turn ignition switch ON again and select “DATA MONITOR”
mode with CONSULT-II.
5. Start engine and run it for at least 1 minute at idle speed.
6. If 1st trip DTC is detected, go to EC-445, "
Diagnostic Procedure"
.
WITH GST
Follow the procedure “WITH CONSULT-II” above.
DTC No. Trouble diagnosis name DTC detecting conditionPossible cause
P0506
0506 Idle speed control system
RPM lower than expected The idle speed is less than the target idle
speed by 100 rpm or more.
Electric throttle control actuator
Intake air leak
SEF174Y
Page 1656 of 3383
DTC P0506 ISC SYSTEMEC-445
C
DE
F
G H
I
J
K L
M A
EC
Revision: November 2009 2006 QX56
Diagnostic ProcedureUBS00H6K
1. CHECK INTAKE AIR LEAK
1. Start engine and let it idle.
2. Listen for an intake air leak after the mass air flow sensor.
OK or NG
OK >> GO TO 2.
NG >> Discover air leak location and repair.
2. REPLACE ECM
1. Stop engine.
2. Replace ECM.
3. Perform initialization of IVIS(NATS) system and registration of all IVIS(NATS) ignition key IDs. Refer to BL-139, "
ECM Re-communicating Function" .
4. Perform EC-77, "
VIN Registration" .
5. Perform EC-78, "
Accelerator Pedal Released Position Learning" .
6. Perform EC-78, "
Throttle Valve Closed Position Learning" .
7. Perform EC-78, "
Idle Air Volume Learning" .
>> INSPECTION END