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.
Fuse check:

Fuse check
?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
     
     
     
Go to step 3.
     
NO
     
     
     
Repair a short in the IG1(SO2)/IG1 ACG wire between secondary HO2S (Sensor 2) and the under-dash fuse/relay box. 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 Secondary HO2S (Sensor 2) side, measure the resistance between test points 1 and 2.
Test condition
Vehicle OFF (LOCK) mode
 
Secondary HO2S (Sensor 2) 4P connectors: disconnected
Test point 1
Secondary HO2S (Sensor 2) 4P connector (male terminals) No. 3 (sensor side):
Test point 2
Secondary HO2S (Sensor 2) 4P connector (male terminals) No. 4 (sensor side):


Is there 8.1?9.9 ? 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 Secondary HO2S (Sensor 2) side, check for continuity between test point 1 and 2.
Test condition
Vehicle OFF (LOCK) mode
 
Secondary HO2S (Sensor 2) 4P connectors: disconnected
Test point 1
Secondary HO2S (Sensor 2) 4P connector (male terminals) No. 3 (sensor side) and No. 4 (sensor side):
Test point 2
Body ground


Is there continuity?

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

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


?2.
Disconnect the following connector.
PCM connector No. 1 (96P)

?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 No. 1 (96P): disconnected
Test point 1
PCM connector No. 1 (96P) No.11
Test point 2
Body ground

Is there continuity?

     
YES
     
     
     
Repair a short in the SO2HT wire between PCM connector No. 1 terminal No. 11 and secondary HO2S (Sensor 2).?
     
NO
     
     
     
The SO2HT wire is not shorted. Go to step 6.
6.
Open wire check (SO2HT line):

Open wire check (SO2HT 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. 3:
Test point 2
PCM connector No. 1 (96P) No. 11


Is there continuity?

     
YES
     
     
     
The SO2HT wire is OK. Go to step 7.
     
NO
     
     
     
Repair an open in the SO2HT wire between PCM connector No. 1 terminal No. 11 and secondary HO2S (Sensor 2).?
7.
Open wire check (IG1(SO2)/IG1 ACG line):

Open wire check (IG1(SO2)/IG1 ACG 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 No. 1 (96P): disconnected
Test point 1
Secondary HO2S (Sensor 2) 4P connector (female terminals) No. 4:
Test point 2
Body ground


Is there battery voltage?

     
YES
     
     
     
The IG1(SO2)/IG1 ACG 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 the IG1(SO2)/IG1 ACG wire between secondary HO2S (Sensor 2) and the under-dash fuse/relay box.?