DTC Troubleshooting: P0141
DTC P0141: Secondary HO2S (Sensor 2) Heater Circuit Malfunction
NOTE: Before you troubleshoot, review the general troubleshooting information.

DTC Description
Confirmed DTC
Pending DTC
P0141 Secondary HO2S (Sensor 2) Heater Circuit Malfunction
    

1.
Problem verification:

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

?2.
Clear the DTC with the HDS.


?3.
Start the engine, and let it idle.

?4.
Check for Pending or Confirmed DTCs with the HDS.
DTC Description
Confirmed DTC
Pending DTC
P0141 Secondary HO2S (Sensor 2) Heater Circuit Malfunction
    

Is DTC P0141 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 (IG1 ACG/IG1(SO2) line):

Shorted wire check (IG1 ACG/IG1(SO2) line)
?1.
Turn the vehicle to the OFF (LOCK) mode.

?2.
Check the following fuse.
Fuse
No. B21 (10 A)
Location
Under-dash fuse/relay box

Is the fuse OK?

     
YES
     
     
     
The IG1 ACG/IG1(SO2) wire is not shorted. Go to step 3.
     
NO
     
     
     
Repair a short in the IG1 ACG/IG1(SO2) wire between the No. B21 (10 A) fuse and secondary HO2S (Sensor 2). Also replace the No. B21 (10 A) fuse.?
3.
Secondary HO2S (Sensor 2) internal heater resistance check:

Secondary HO2S (Sensor 2) internal heater resistance check
?1.
Disconnect the following connector.
Secondary HO2S (Sensor 2) 4P connector

?2.
At the sensor side, measure the resistance between test points 1 and 2.
Test condition
Vehicle OFF (LOCK) mode
 
Secondary HO2S (Sensor 2) 4P connector: disconnected
Test point 1
Secondary HO2S (Sensor 2) 4P connector No. 3 (secondary HO2S (Sensor 2) side)
Test point 2
Secondary HO2S (Sensor 2) 4P connector No. 4 (secondary HO2S (Sensor 2) side)


Is there 4.2?6.6 ? at room temperature?

     
YES
     
     
     
Go to step 4.
     
NO
     
     
     
4.
Secondary HO2S (Sensor 2) internal circuit check:

Secondary HO2S (Sensor 2) internal circuit check
?1.
At the sensor side, check for continuity between test point 1 and 2.
Test condition
Vehicle OFF (LOCK) mode
 
Secondary HO2S (Sensor 2) 4P connector: disconnected
Test point 1
Secondary HO2S (Sensor 2) 4P connector No. 3 and No. 4 (secondary HO2S (Sensor 2) side)
Test point 2
Body ground


Is there continuity?

     
YES
     
     
     
     
NO
     
     
     
Go to step 5.
5.
Shorted wire check (SO2HT/SO2 HT line):

Shorted wire check (SO2HT/SO2 HT line)
?1.
Jump the SCS line with the HDS, and wait more than 1 minute.


?2.
Disconnect the following connector.
PCM connector A (50P)

?3.
Check for continuity between test points 1 and 2.
Test condition
Vehicle OFF (LOCK) mode
 
Secondary HO2S (Sensor 2) 4P connector: disconnected
 
PCM connector A (50P): disconnected
Test point 1
PCM connector A (50P) No. 4
Test point 2
Body ground

Is there continuity?

     
YES
     
     
     
Repair a short in the SO2HT/SO2 HT wire between the PCM (A4) and secondary HO2S (Sensor 2).?
     
NO
     
     
     
The SO2HT/SO2 HT wire is not shorted. Go to step 6.
6.
Open wire check (SO2HT/SO2 HT line):

Open wire check (SO2HT/SO2 HT 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 A (50P): disconnected
Test point 1
Secondary HO2S (Sensor 2) 4P connector No. 4
Test point 2
PCM connector A (50P) No. 4


Is there continuity?

     
YES
     
     
     
The SO2HT/SO2 HT wire is OK. Go to step 7.
     
NO
     
     
     
Repair an open in the SO2HT/SO2 HT wire between the PCM (A4) and secondary HO2S (Sensor 2).?
7.
Open wire check (IG1 ACG/IG1(SO2) line):

Open wire check (IG1 ACG/IG1(SO2) line)
?1.
Turn the vehicle to the ON mode.

?2.
Measure the voltage between test points 1 and 2.
Test condition
Vehicle ON mode
 
Secondary HO2S (Sensor 2) 4P connector: disconnected
 
PCM connector A (50P): disconnected
Test point 1
Secondary HO2S (Sensor 2) 4P connector No. 3
Test point 2
Body ground


Is there battery voltage?

     
YES
     
     
     
The IG1 ACG/IG1(SO2) wire is OK. Check for any authorized service information related to the DTCs or symptoms you are troubleshooting, or substitute a known-good PCM, then recheck. If DTC P0141 goes away and the PCM was substituted, replace the original PCM.?
     
NO
     
     
     
Repair an open in theIG1 ACG/IG1(SO2) wire between the No. B21 (10 A) fuse in the under-dash fuse/relay box and secondary HO2S (Sensor 2).?