Page 1376 of 3383
DTC P0037, P0038, P0057, P0058 HO2S2 HEATEREC-165
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Revision: November 2009 2006 QX56
Wiring DiagramUBS00H0R
BANK 1
BBWA1672E
Page 1380 of 3383

DTC P0037, P0038, P0057, P0058 HO2S2 HEATEREC-169
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Revision: November 2009 2006 QX56
2. CHECK HO2S2 POWER SUPPLY CIRCUIT
1. Disconnect heated oxygen sensor 2 harness connector.
2. Turn ignition switch ON.
3. Check voltage between HO2S2 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 connector E119
10A fuse
Harness for open or short between heated oxygen sensor 2 and fuse
>> Repair harness or connectors.
4. CHECK HO2S2 OUTPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check harness continuity between ECM terminal and HO2S2 terminal as follows. 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.
BBIA0435E
Voltage: Battery voltage
PBIB0112E
DTC Te r m i n a l s
Bank
ECM Sensor
P0037, P0038 6 21
P0057, P0058 25 22
Continuity should exist.
Page 1385 of 3383
EC-174Revision: November 2009
DTC P0101 MAF SENSOR
2006 QX56
Wiring DiagramUBS00H10
BBWA1674E
Page 1388 of 3383

DTC P0101 MAF SENSOREC-177
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Revision: November 2009 2006 QX56
6. CHECK MAF SENSOR GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check harness continuity between MAF sensor terminal 3 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 7.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
7. CHECK MAF SENSOR INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Check harness continuity between MAF sensor terminal 4 and ECM terminal 51. Refer to Wiring Diagram.
2. 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 INTAKE AIR TEMPERATURE SENSOR
Refer to EC-191, "
Component Inspection" .
OK or NG
OK >> GO TO 9.
NG >> Replace intake air temperature sensor.
9. CHECK EVAP CONTROL SYSTEM PRESSURE SENSOR
Refer to EC-404, "
Component Inspection" .
OK or NG
OK >> GO TO 10.
NG >> Replace EVAP control system pressure sensor.
10. CHECK MASS AIR FLOW SENSOR
Refer to EC-178, "
Component Inspection" .
OK or NG
OK >> GO TO 11.
NG >> Replace mass air flow sensor.
11 . CHECK INTERMITTENT INCIDENT
Refer to EC-144, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
>> INSPECTION END
Continuity should exist.
Continuity should exist.
Page 1393 of 3383
EC-182Revision: November 2009
DTC P0102, P0103 MAF SENSOR
2006 QX56
Wiring DiagramUBS00H18
BBWA1674E
Page 1396 of 3383

DTC P0102, P0103 MAF SENSOREC-185
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Revision: November 2009 2006 QX56
6. CHECK MAF SENSOR GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check harness continuity between MAF sensor terminal 3 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 7.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
7. CHECK MAF SENSOR INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Check harness continuity between MAF sensor terminal 4 and ECM terminal 51. Refer to Wiring Diagram.
2. 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 MASS AIR FLOW SENSOR
Refer to EC-186, "
Component Inspection" .
OK or NG
OK >> GO TO 9.
NG >> Replace mass air flow sensor.
9. CHECK INTERMITTENT INCIDENT
Refer to EC-144, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
>> INSPECTION END
Continuity should exist.
Continuity should exist.
Page 1400 of 3383
DTC P0112, P0113 IAT SENSOREC-189
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Revision: November 2009 2006 QX56
Wiring DiagramUBS00H1F
BBWA0879E
Page 1402 of 3383

DTC P0112, P0113 IAT SENSOREC-191
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Revision: November 2009 2006 QX56
3. CHECK INTAKE AIR TEMPERATURE SENSOR GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check harness continuity between mass air flow sensor terminal 6 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 4.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
4. CHECK INTAKE AIR TEMPERATURE SENSOR
Refer to EC-191, "
Component Inspection" .
OK or NG
OK >> GO TO 5.
NG >> Replace mass air flow sensor (with intake air temperature sensor).
5. CHECK INTERMITTENT INCIDENT
Refer to EC-144, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
>> INSPECTION END
Component InspectionUBS00H1H
INTAKE AIR TEMPERATURE SENSOR
1. Check resistance between mass air flow sensor terminals 5 and
6 under the following conditions.
2. If NG, replace mass air flow sensor (with intake air temperature sensor).
Removal and InstallationUBS00H1I
MASS AIR FLOW SENSOR
Refer to EM-15, "AIR CLEANER AND AIR DUCT" .
Continuity should exist.
Intake air temperature
°C (°F) Resistance k Ω
25 (77) 1.800 - 2.200
BBIA0355E
SEF012P