DTC Troubleshooting: P2238
DTC P2238: A/F Sensor (Sensor 1) AFS+ Circuit Low Voltage
NOTE: Before you troubleshoot, record all freeze data and any on-board snapshot, and 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 ignition switch to ON (II), or press the engine start/stop button to select 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), the PGM-FI subrelay, and the PCM.?
2.
Shorted wire check (AFS+ line):

Shorted wire check (AFS+ line)
?1.
Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.

?2.
Jump the SCS line with the HDS.


?3.
Disconnect the following connectors.

?4.
Check for continuity between test points 1 and 2.
Test condition
IG LOCK (0) or OFF mode
 
A/F sensor (Sensor 1) 4P connector: disconnected
 
PCM connector C (51P): disconnected
Test circuit
AFS+
Test point 1
PCM connector C (51P) No. 48 (RED)
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), then do the repair verification.
     
NO
     
     
     
The AFS+ wire is OK. Go to step 3.
3.
PCM internal circuit check:

PCM internal circuit check:
?1.
Exit the SCS mode with the HDS.


?2.
Reconnect PCM connector C (51P).

?3.
Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode.

?4.
Measure the voltage between test points 1 and 2.
Test condition
IG ON (II) or ON mode
 
A/F sensor (Sensor 1) 4P connector: disconnected
Test circuit
AFS+
Test point 1
A/F sensor (Sensor 1) 4P connector No. 2 (RED)
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 do the repair verification.
     
NO
     
     
     
The PCM internal circuit is OK. Replace the A/F sensor (Sensor 1), then do the repair verification.
Repair verification (OBD STATUS check):

?1.
Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.

?2.
Reconnect all connectors.

?3.
Exit the SCS mode with the HDS.


?4.
Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode.

?5.
Reset the PCM with the HDS.


?6.
Do the PCM idle learn procedure.

?7.
Monitor the OBD STATUS for DTC P2238 in the DTCs MENU with the HDS.
DTC Description
OBD Status
P2238 A/F Sensor (Sensor 1) AFS+ Circuit Low Voltage
 

Does the HDS indicate PASSED, FAILED, or NOT COMPLETED?

     
PASSED
     
     
     
Troubleshooting is complete. If the PCM was substituted, replace the original PCM. Check for other DTC after this troubleshooting. If any other Pending or Confirmed DTCs were indicated, go to the indicated DTC's troubleshooting.?
     
FAILED
     
     
     
Go to step 1 and recheck. If the PCM was updated, substitute a known-good PCM, then check the OBD STATUS again.
     
NOT COMPLETED
     
     
     
Keep idling until a result comes on.