DTC Troubleshooting: P2A01
DTC P2A01: Secondary HO2S (Sensor 2) Circuit Range/Performance Problem
NOTE: Before you troubleshoot, review the general troubleshooting information.

DTC Description
Confirmed DTC
Pending DTC
P2A01 Secondary HO2S (Sensor 2) Circuit Range/Performance Problem
    

1.
Problem verification:

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

?2.
Clear the DTC with the HDS.


?3.
Wait 10 seconds or more.

?4.
Check for Pending or Confirmed DTCs with the HDS.
DTC Description
Confirmed DTC
Pending DTC
P2A01 Secondary HO2S (Sensor 2) Circuit Range/Performance Problem
    

Is DTC P2A01 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 connector.
PCM connector A (50P)

?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 A (50P): disconnected
Test point 1
Secondary HO2S (Sensor 2) 4P connector (male terminals) No. 1:
Test point 2
Body ground


Is there continuity?

     
YES
     
     
     
Repair a short in the SO2 wire between the PCM (A47) 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 A (50P): disconnected
Test point 1
Secondary HO2S (Sensor 2) 4P connector (male terminals) No. 1:
Test point 2
PCM connector A (50P) No. 47


Is there continuity?

     
YES
     
     
     
The SO2 wire is OK. Go to step 4.
     
NO
     
     
     
Repair an open in the SO2 wire between the PCM (A47) and secondary HO2S (Sensor 2).?
4.
Shorted wire check (SO2 SG/SO2SG line):

Shorted wire check (SO2 SG/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 A (50P): disconnected
Test point 1
Secondary HO2S (Sensor 2) 4P connector (male terminals) No. 2:
Test point 2
Body ground


Is there continuity?

     
YES
     
     
     
Repair a short in the SO2 SG/SO2SG wire between the PCM (A48) and secondary HO2S (Sensor 2).?
     
NO
     
     
     
The SO2 SG/SO2SG wire is not shorted. Go to step 5.
5.
Open wire check (SO2 SG/SO2SG line):

Open wire check (SO2 SG/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 A (50P): disconnected
Test point 1
Secondary HO2S (Sensor 2) 4P connector (male terminals) No. 2:
Test point 2
PCM connector A (50P) No. 48


Is there continuity?

     
YES
     
     
     
The SO2 SG/SO2SG wire is OK. Go to step 6.
     
NO
     
     
     
Repair an open in the SO2 SG/SO2SG wire between the PCM (A48) and secondary HO2S (Sensor 2).?
6.
Secondary HO2S (Sensor 2) check:

Secondary HO2S (Sensor 2) check
?1.
Substitute a known-good secondary HO2S (Sensor 2).

?2.
Reconnect all connectors.

?3.
Exit the SCS mode with the HDS.


?4.
Turn the vehicle to the ON mode.

?5.
Clear the DTC with the HDS.


?6.
Wait 10 seconds or more.

?7.
Check for Pending or Confirmed DTCs with the HDS.
DTC Description
Confirmed DTC
Pending DTC
P2A01 Secondary HO2S (Sensor 2) Circuit Range/Performance Problem
    

Is DTC P2A01 indicated?

     
YES
     
     
     
Secondary HO2S (Sensor 2) 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 P2A01 goes away and the PCM was substituted, replace the original PCM.?
     
NO