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EC-254Revision: November 2009
DTC P0137, P0157 HO2S2
2006 QX56
DTC Confirmation ProcedureUBS00H8E
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
TESTING CONDITION:
For better results, perform “DTC WORK SUPPORT” at a temperature of 0 to 30 °C (32 to 86 ° F).
1. Turn ignition switch ON and select “DATA MONITOR ” mode with
CONSULT-II.
2. Start engine and warm it up to the normal operating tempera- ture.
3. Turn ignition switch OFF and wait at least 10 seconds.
4. Start engine and keep the engine speed between 3,500 and 4,000 rpm for at least 1 minute under no load.
5. Let engine idle for 1 minute.
6. Make sure that “COOLAN TEMP/S ” indicates more than 70°C
(158 °F).
If not, warm up engine and go to next step when “COOLAN
TEMP/S ” indication reaches to 70 °C (158 °F).
7. Open engine hood.
8. Select “HO2S2 (B1) P1147 ” (for DTC P0137) or “HO2S2 (B2) P1167” (for DTC P0157) of “HO2S2” in
“DTC WORK SUPPORT ” mode with CONSULT-II.
9. Start engine and following the instruction of CONSULT-II.
NOTE:
It will take at most 10 minutes until “COMPLETED” is displayed.
10. Make sure that “OK ” is displayed after touching “SELF-DIAG RESULTS”.
If “NG ” is displayed, refer to EC-259, "
Diagnostic Procedure" .
If “CAN NOT BE DIAGNOSED ” is displayed, perform the following.
a. Turn ignition switch OFF and leave the vehicle in a cool place (soak the vehicle).
b. Return to step 1.
Overall Function CheckUBS00H8F
Use this procedure to check the overall function of the heated oxygen sensor 2 circuit. During this check, a 1st
trip DTC might not be confirmed.
WITH GST
1. Start engine and warm it up to the normal operating temperature.
2. Turn ignition switch OFF and wait at least 10 seconds.
3. Start engine and keep the engine speed between 3,500 and 4,000 rpm for at least 1 minute under no load.
4. Let engine idle for 1 minute.
5. Set voltmeter probes between ECM terminal 55 [HO2S2 (B1) signal] or 74 [HO2S2 (B2) signal] and ground.
SEF174Y
PBIB2373E
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DTC P0137, P0157 HO2S2EC-255
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Revision: November 2009 2006 QX56
6. Check the voltage when revving up to 4,000 rpm under no load
at least 10 times.
(Depress and release accelerator pedal as soon as possible.)
The voltage should be above 0.58V at least once during this
procedure.
If the voltage can be confirmed in step 6, step 7 is not nec-
essary.
7. Keep vehicle at idling for 10 minutes, then check the voltage. Or check the voltage when coasting from 80 km/h (50 MPH) in D
position.
The voltage should be above 0.58V at least once during this
procedure.
8. If NG, go to EC-259, "
Diagnostic Procedure" .
PBIB2054E
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EC-256Revision: November 2009
DTC P0137, P0157 HO2S2
2006 QX56
Wiring DiagramUBS00H8G
BANK 1
BBWA1678E
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DTC P0137, P0157 HO2S2EC-257
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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.
TER-
MINAL NO. WIRE
COLOR ITEM
CONDITION DATA (DC Voltage)
6GR Heated oxygen sensor 2
heater (bank 1) [Engine is running]
Engine speed: Below 3,600 rpm after the
following conditions are met.
–Engine: After warming up
–Keeping the engine speed between 3,500
and 4,000 rpm for 1 minute and at idle for 1
minute under no load
0 - 1.0V
[Ignition switch: ON]
Engine: Stopped
[Engine is running]
Engine speed: Above 3,600 rpm. BATTERY VOLTAGE
(11 - 14V)
55 R Heated oxygen sensor 2
(bank 1) [Engine is running]
Revving engine from idle to 3,000 rpm
quickly after the following conditions are
met.
–Engine: After warming up
–Keeping the engine speed between 3,500
and 4,000 rpm for 1 minute and at idle for 1
minute under no load
0 - Approximately 1.0V
78 B/W Sensor ground
(Heated oxygen sensor 2) [Engine is running]
Warm-up condition
Idle speed
Approximately 0V
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EC-258Revision: November 2009
DTC P0137, P0157 HO2S2
2006 QX56
BANK 2
BBWA1679E
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DTC P0137, P0157 HO2S2EC-259
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Revision: November 2009 2006 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 ProcedureUBS00H8H
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.
TER-
MINAL NO. WIRE
COLOR ITEM
CONDITION DATA (DC Voltage)
25 O/G Heated oxygen sensor 2
heater (bank 2) [Engine is running]
Engine speed: Below 3,600 rpm after the
following conditions are met.
–Engine: After warming up
–Keeping the engine speed between 3,500
and 4,000 rpm for 1 minute and at idle for 1
minute under no load
0 - 1.0V
[Ignition switch: ON]
Engine: Stopped
[Engine is running]
Engine speed: Above 3,600 rpm. BATTERY VOLTAGE
(11 - 14V)
74 L Heated oxygen sensor 2
(bank 2) [Engine is running]
Revving engine from idle to 3,000 rpm
quickly after the following conditions are
met.
–Engine: After warming up
–Keeping the engine speed between 3,500
and 4,000 rpm for 1 minute and at idle for 1
minute under no load
0 - Approximately 1.0V
78 B/W Sensor ground
(Heated oxygen sensor 2) [Engine is running]
Warm-up condition
Idle speed
Approximately 0V
BBIA0354E
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EC-260Revision: November 2009
DTC P0137, P0157 HO2S2
2006 QX56
2. CLEAR THE SELF-LEARNING DATA
With CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Select “SELF-LEARNING CONT ” in “WORK SUPPORT” mode
with CONSULT-II.
3. Clear the self-learning control coefficient by touching “CLEAR”.
4. Run engine for at least 10 minutes at idle speed. Is the 1st trip DTC P0171 or P0174 detected?
Is it difficult to start engine?
Without CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Turn ignition switch OFF.
3. Disconnect mass air flow sensor harness connector, and restart and run engine for at least 5 seconds at idle speed.
4. Stop engine and reconnect mass air flow sensor harness con- nector.
5. Make sure DTC P0102 is displayed.
6. Erase the DTC memory. Refer to EC-61, "
HOW TO ERASE
EMISSION-RELATED DIAGNOSTIC INFORMATION" .
7. Make sure DTC P0000 is displayed.
8. Run engine for at least 10 minutes at idle speed. Is the 1st trip DTC P0171 or P0174 detected?
Is it difficult to start engine?
Ye s o r N o
Yes >> Perform trouble diagnosis for DTC P0171 or P0174. Refer to EC-288, "DTC P0171, P0174 FUEL
INJECTION SYSTEM FUNCTION" .
No >> GO TO 3.
SEF968Y
BBIA0368E
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DTC P0137, P0157 HO2S2EC-261
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3. CHECK HO2S2 GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect heated oxygen sensor 2 harness connector.
3. Disconnect ECM harness connector.
4. Check harness continuity between ECM terminal 78 and HO2S2 terminal 4. Refer to Wiring Diagram.
5. 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 HO2S2 INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Check harness continuity between ECM terminal and HO2S2 terminal as follows. Refer to Wiring Diagram.
2. Check harness continuity between the following terminals and ground. Refer to Wiring Diagram.
3. Also check harness for 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. Continuity should exist.
BBIA0435E
DTC
Te r m i n a l s
Bank
ECM Sensor
P0137 5511
P0157 7412
Continuity should exist.
DTC Te r m i n a l s
Bank
ECM Sensor
P0137 5511
P0157 7412
Continuity should not exist.