Page 1405 of 3383
EC-194Revision: November 2009
DTC P0117, P0118 ECT SENSOR
2006 QX56
Wiring DiagramUBS00H1M
BBWA1676E
Page 1407 of 3383

EC-196Revision: November 2009
DTC P0117, P0118 ECT SENSOR
2006 QX56
4. CHECK ECT SENSOR GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check harness continuity between ECT sensor terminal 2 and ECM terminal 67. Refer to Wiring Diagram.
4. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 6.
NG >> GO TO 5.
5. DETECT MALFUNCTIONING PART
Check the following.
Harness connector F26, F101
Harness for open and short between ECT sensor and ECM
>> Repair open circuit or short to ground or short to power in harness or connectors.
6. CHECK ENGINE COOLANT TEMPERATURE SENSOR
Refer to EC-196, "
Component Inspection" .
OK or NG
OK >> GO TO 7.
NG >> Replace engine coolant temperature sensor.
7. CHECK INTERMITTENT INCIDENT
Refer to EC-144, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
>> INSPECTION END
Component InspectionUBS00H1O
ENGINE COOLANT TEMPERATURE SENSOR
1. Check resistance between engine coolant temperature sensor
terminals 1 and 2 as shown in the figure.Continuity should exist.
PBIB2005E
Page 1411 of 3383
EC-200Revision: November 2009
DTC P0122, P0123 TP SENSOR
2006 QX56
Wiring DiagramUBS00H1U
BBWA1677E
Page 1413 of 3383

EC-202Revision: November 2009
DTC P0122, P0123 TP SENSOR
2006 QX56
2. CHECK THROTTLE POSITION SENSOR 2 POWER SUPPLY CIRCUIT-I
1. Disconnect electric throttle control actuator harness connector.
2. Turn ignition switch ON.
3. Check voltage between electric throttle control actuator terminal 2 and ground with CONSULT-II or tester.
OK or NG
OK >> GO TO 7.
NG >> GO TO 3.
3. CHECK THROTTLE POSITION SENSOR 2 POWER SUPPLY CIRCUIT-II
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check harness continuity between electric throttle control actuator terminal 2 and ECM terminal 47. Refer to Wiring Diagram.
OK or NG
OK >> GO TO 4.
NG >> Repair or replace open circuit.
4. CHECK THROTTLE POSITION SENSOR 2 POWER SUPPLY CIRCUIT-III
Check harness for short to power and short to ground, between the following terminals.
OK or NG
OK >> GO TO 5.
NG >> Repair short to ground or short to power in harness or connectors.
5. CHECK ACCELERATOR PEDAL POSITION SENSOR
Refer to EC-574, "
Component Inspection" .
OK or NG
OK >> GO TO 11.
NG >> GO TO 6.
PBIB1480E
Voltage: Approximately 5V
PBIB2065E
Continuity should exist.
ECM terminal Sensor terminal Reference Wiring Diagram
47 Electric throttle control actuator terminal 2 EC-200
91APP sensor terminal 6 EC-569
Page 1414 of 3383

DTC P0122, P0123 TP SENSOREC-203
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Revision: November 2009 2006 QX56
6. REPLACE ACCELERATOR PEDAL ASSEMBLY
1. Replace the accelerator pedal assembly.
2. Perform EC-78, "
Accelerator Pedal Released Position Learning" .
3. Perform EC-78, "
Throttle Valve Closed Position Learning" .
4. Perform EC-78, "
Idle Air Volume Learning" .
>> INSPECTION END
7. CHECK THROTTLE POSITION SENSOR 2 GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check harness continuity between electric throttle control actuator terminal 4 and ECM terminal 66. Refer to Wiring Diagram.
4. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 8.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
8. CHECK THROTTLE POSITION SENSOR 2 INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Check harness continuity between ECM terminal 69 and electric throttle control actuator terminal 3. Refer to Wiring Diagram.
2. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 9.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
9. CHECK THROTTLE POSITION SENSOR
Refer to EC-204, "
Component Inspection" .
OK or NG
OK >> GO TO 11.
NG >> GO TO 10.
10. REPLACE ELECTRIC THROTTLE CONTROL ACTUATOR
1. Replace the electric throttle control actuator.
2. Perform EC-78, "
Throttle Valve Closed Position Learning" .
3. Perform EC-78, "
Idle Air Volume Learning" .
>> INSPECTION END
11 . CHECK INTERMITTENT INCIDENT
Refer to EC-144, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
>> INSPECTION END
Continuity should exist.
Continuity should exist.
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DTC P0125 ECT SENSOREC-207
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Revision: November 2009 2006 QX56
3. CHECK THERMOSTAT OPERATION
When the engine is cold [lower than 70 °C (158 °F)] condition, grasp lower radiator hose and confirm the engine
coolant does not flow.
OK or NG
OK >> GO TO 4.
NG >> Repair or replace thermostat. Refer to CO-21, "
THERMOSTAT AND WATER PIPING" .
4. CHECK INTERMITTENT INCIDENT
Refer to EC-144, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
Refer to EC-194, "
Wiring Diagram" .
>> INSPECTION END
Component InspectionUBS00H22
ENGINE COOLANT TEMPERATURE SENSOR
1. Check resistance between engine coolant temperature sensor
terminals 1 and 2 as shown in the figure.
2. If NG, replace engine coolant temperature sensor.
Removal and InstallationUBS00H23
ENGINE COOLANT TEMPERATURE SENSOR
Refer to CO-21, "THERMOSTAT AND WATER PIPING" .
PBIB2005E
Engine coolant temperature °C (°F) Resistance kΩ
20 (68) 2.1 - 2.9
50 (122) 0.68 - 1.00
90 (194) 0.236 - 0.260
SEF012P
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DTC P0127 IAT SENSOREC-209
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Revision: November 2009 2006 QX56
b. Select “DATA MONITOR ” mode with CONSULT-II.
c. Check the engine coolant temperature.
d. If the engine coolant temperature is not less than 90 °C (194 °F),
turn ignition switch OFF and cool down engine.
Perform the following steps before engine coolant tempera-
ture is above 90 °C (194 °F).
2. Turn ignition switch ON.
3. Select “DATA MONITOR ” mode with CONSULT-II.
4. Start engine.
5. Hold vehicle speed at more than 70 km/h (43 MPH) for 100 con- secutive seconds.
6. If 1st trip DTC is detected, go to EC-209, "
Diagnostic Procedure" .
WITH GST
Follow the procedure “WITH CONSULT-II” above.
Diagnostic ProcedureUBS00H27
1. CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten three ground screws on the body. Refer to EC-150, "
Ground Inspection" .
OK or NG
OK >> GO TO 2.
NG >> Repair or replace ground connections.
2. CHECK INTAKE AIR TEMPERATURE SENSOR
Refer to EC-210, "
Component Inspection" .
OK or NG
OK >> GO TO 3.
NG >> Replace mass air flow sensor (with intake air temperature sensor).
3. CHECK INTERMITTENT INCIDENT
Refer to EC-144, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
Refer to EC-189, "
Wiring Diagram" .
>> INSPECTION END
SEF189Y
BBIA0354E
Page 1427 of 3383
EC-216Revision: November 2009
DTC P0130, P0150 A/F SENSOR 1
2006 QX56
Wiring DiagramUBS00HAC
BANK 1
BBWA2111E