DTC Troubleshooting: P2238
DTC P2238: A/F Sensor (Sensor 1) AFS+ Circuit Low Voltage
NOTE: Before you troubleshoot, review the general troubleshooting information.

DTC Description
Confirmed DTC
Pending DTC
Freeze Frame
P2238 A/F Sensor (Sensor 1) AFS+ Circuit Low Voltage
      

1.
Problem verification:

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

?2.
Clear the DTC with the HDS.


?3.
Check for Pending or Confirmed DTCs with the HDS.
DTC Description
Confirmed DTC
Pending DTC
Freeze Frame
P2238 A/F Sensor (Sensor 1) AFS+ Circuit Low Voltage
      

Is DTC P2238 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 the A/F sensor (Sensor 1) and the PCM. If the freeze data/on-board snapshot of this DTC is recorded, try to reproduce the failure under the same conditions with the freeze data/on-board snapshot.?
2.
Shorted wire check (AFS+ line):

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

?2.
Jump the SCS line with the HDS.


?3.
Disconnect the following connectors.
A/F sensor (Sensor 1) 4P connector
PCM connector C (51P)

?4.
Check for continuity between test points 1 and 2.
Test condition
Vehicle OFF (LOCK) mode
 
A/F sensor (Sensor 1) 4P connector: disconnected
 
PCM connector C (51P): disconnected
Test point 1
PCM connector C (51P) No. 48
Test point 2
Body ground

Is there continuity?

     
YES
     
     
     
Repair a short in the AFS+ wire between the PCM (C48) and the A/F sensor (Sensor 1).?
     
NO
     
     
     
The AFS+ wire is OK. Go to step 3.
3.
PCM internal circuit check:

PCM internal circuit check:
?1.
Reconnect PCM connector C (51P).

?2.
Exit the SCS mode with the HDS.


?3.
Turn the vehicle to the ON mode.

?4.
Measure the voltage between test points 1 and 2.
Test condition
Vehicle ON mode
 
A/F sensor (Sensor 1) 4P connector: disconnected
Test point 1
A/F sensor (Sensor 1) 4P connector No. 2
Test point 2
Body ground


Is there about 0.2 V or less?

     
YES
     
     
     
Update the PCM if it does not have the latest software, or substitute a known-good PCM, then recheck. If DTC P2238 goes away and the PCM was updated, troubleshooting is complete. If DTC P2238 goes away and the PCM was substituted, replace the original PCM.?
     
NO
     
     
     
The PCM internal circuit is OK. Replace the A/F sensor (Sensor 1).?