DTC Troubleshooting: P0140
DTC P0140: Secondary HO2S (Sensor 2) Circuit No Activity
NOTE:
Before you troubleshoot, review the general troubleshooting information.
Check for damage or corrosion at secondary HO2S (Sensor 2) connector terminals.

DTC Description
Confirmed DTC
Pending DTC
P0140 Secondary HO2S (Sensor 2) Circuit No Activity
    

1.
Problem verification:

Problem verification
?1.
Turn the vehicle to the ON mode.

?2.
Clear the DTC with the HDS.


?3.
Start the engine.

?4.
Hold the engine speed at 3,000 rpm without load (in neutral) until the radiator fan comes on, then let it idle.

?5.
Check for Pending or Confirmed DTCs with the HDS.
DTC Description
Confirmed DTC
Pending DTC
P0140 Secondary HO2S (Sensor 2) Circuit No Activity
    

Is DTC P0140 indicated?

     
YES
     
     
     
The failure is duplicated. Go to step 2.
     
NO
     
     
     
Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at secondary HO2S (Sensor 2) and the PCM. If the on-board snapshot of this DTC is recorded, try to reproduce the failure under the same conditions with the on-board snapshot.?
2.
Shorted wire check (SO2 line):

Shorted wire check (SO2 line)
?1.
Turn the vehicle to the OFF (LOCK) mode.

?2.
Jump the SCS line with the HDS, and wait more than 1 minute.


?3.
Disconnect the following connectors.
Secondary HO2S (Sensor 2) 4P connector
PCM connector No. 1 (96P)

?4.
Check for continuity between test points 1 and 2.
Test condition
Vehicle OFF (LOCK) mode
 
Secondary HO2S (Sensor 2) 4P connector: disconnected
 
PCM connector No. 1 (96P): disconnected
Test point 1
Secondary HO2S (Sensor 2) 4P connector (female terminals) No. 2:
Test point 2
Body ground


Is there continuity?

     
YES
     
     
     
Repair a short in the SO2 wire between PCM connector No. 1 terminal No. 22 and secondary HO2S (Sensor 2).?
     
NO
     
     
     
The SO2 wire is not shorted. Go to step 3.
3.
Open wire check (SO2 line):

Open wire check (SO2 line)
?1.
Check for continuity between test points 1 and 2.
Test condition
Vehicle OFF (LOCK) mode
 
Secondary HO2S (Sensor 2) 4P connector: disconnected
 
PCM connector No. 1 (96P): disconnected
Test point 1
Secondary HO2S (Sensor 2) 4P connector (female terminals) No. 2:
Test point 2
PCM connector No. 1 (96P) No. 22


Is there continuity?

     
YES
     
     
     
The SO2 wire is OK. Go to step 4.
     
NO
     
     
     
Repair an open in the SO2 wire between PCM connector No. 1 terminal No. 22 and secondary HO2S (Sensor 2).?
4.
Open wire check (SO2SG line):

Open wire check (SO2SG line)
?1.
Check for continuity between test points 1 and 2.
Test condition
Vehicle OFF (LOCK) mode
 
Secondary HO2S (Sensor 2) 4P connector: disconnected
 
PCM connector No. 1 (96P): disconnected
Test point 1
Secondary HO2S (Sensor 2) 4P connector (female terminals) No. 1:
Test point 2
PCM connector No. 1 (96P) No. 24


Is there continuity?

     
YES
     
     
     
The SO2SG wire is OK. Replace secondary HO2S (Sensor 2).?
     
NO
     
     
     
Repair an open in the SO2SG wire between PCM connector No. 1 terminal No. 24 and secondary HO2S (Sensor 2).?