1A
DTC P0140: O2 Sensor (HO2S) Circuit No Activity Detected (Sensor-2)
Wiring Diagram
1. Shield wire 4. “IG” fuse 7. To HO2S-1 heater 10. Relay box
2. Ignition switch 5. HO2S-2 8. ECM 11. “IGN1” fuse
3. Circuit fuse box 6. Heater 9. To other sensor      
DTC Detecting Condition and Trouble Area
DTC detecting condition Trouble area
HO2S-2 voltage is higher than specified value after warming up engine (circuit open).
(2 driving cycle detection logic)
HO2S-2
HO2S-2 circuit
ECM
Exhaust gas leakage
Air intake system
DTC Confirmation Procedure
WARNING:
When performing a road test, select a place where there is no traffic or possibility of a traffic accident and be very careful during testing to avoid occurrence of an accident.
Road test should be carried out with 2 persons, a driver and a tester, on a level road.
1) With ignition switch turned OFF, connect scan tool.
2) Turn ON ignition switch and clear DTC using scan tool.
3) Start engine and warm up to normal operating temperature.
4) Increase vehicle speed to 60 – 80 km/h (37 – 50 mile/h) at 5th gear or D range.
5) Release accelerator pedal and with engine brake applied, keep vehicle coasting (with fuel cut for 4 sec. or more), then stop vehicle and run engine at idle speed for 60 sec. or more.
6) Check DTC and pending DTC.
DTC Troubleshooting
Step Action YES NO
1
Was “Engine and Emission Control System Check” performed?
Go to Step 2.
2
HO2S-2 ground check
1) Disconnect connector from HO2S-2 with ignition switch turned OFF.
2) Check for proper connection to HO2S-2 connector at “RED/BLU”, “WHT”, “BLK/ BLU” and “BLK/WHT” wire terminals.
3) If wire and connection are OK, measure resistance between “BLK/BLU” wire terminal of HO2S-2 connector and engine ground.
Is resistance less than 5 Ω?
Go to Step 3.
“BLK/BLU” wire open or high resistance circuit. Poor “E118-35” terminal connection.
Faulty ECM ground. If they are OK, substitute a known-good ECM and recheck.
3
Wire circuit check
1) Turn OFF ignition switch.
2) Measure resistance between “WHT” wire terminal of HO2S-2 connector and “E119-33” terminal of ECM connector.
Is resistance less than 5 Ω?
Go to Step 4.
“WHT” wire high resistance circuit or open circuit. Poor “E119-33” terminal connection.
If they are OK, substitute a known-good ECM and recheck.
4
HO2S-2 signal circuit check
1) Disconnect connectors from ECM with ignition switch turned OFF.
2) Measure voltage between “WHT” wire terminal of HO2S-2 sensor connector and vehicle body ground.
Is voltage 0 V?
Go to Step 5.
“WHT” wire shorted to other circuits.
5
HO2S-2 heater circuit check
Is circuit in good condition?
Go to Step 6.
Repair or replace it. If circuit is OK, substitute a known-good ECM and recheck.
6
HO2S-2 check
Is it in good condition?
Substitute a known-good ECM and recheck.
Repair or replace.
NOTE:
Upon completion of inspection and repair work, perform “DTC Confirmation Procedure” and
confirm that the trouble has been corrected.