DTC P2238, P2241

DTC P2238  : Rear A/F Sensor (Bank 1, Sensor 1) IP Circuit Low Voltage

DTC P2241  : Front A/F Sensor (Bank 2, Sensor 1) IP Circuit Low Voltage

DTC (PGM-FI)

1. 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 Rear A/F Sensor (Bank 1, Sensor 1) IP Circuit Low Voltage
   P2241 Front A/F Sensor (Bank 2, Sensor 1) IP Circuit Low Voltage

   Is DTC P2238 and/or P2241 * 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 (IPB1 (IPB2) * line):

   -1. Turn the vehicle to the OFF (LOCK) mode.

   -2. Jump the SCS line with the HDS.

   -3. Disconnect the following connectors.

   PCM connector C (51P)

   A/F sensor (Sensor 1) 6P connector

   -4. Check for continuity between test points 1 and 2.

   Test condition	Vehicle OFF (LOCK) mode
   	A/F sensor (Sensor 1) 6P connector: disconnected
   	PCM connector C (51P): disconnected
   Test circuit	IPB1 (IPB2) *
   Test point 1	PCM connector C (51P) No. 37 (GRN)
   	PCM connector C (51P) No. 38 (PUR) *
   Test point 2	Body ground

   Courtesy of HONDA, U.S.A., INC.

   Is there continuity?

   YES 

   Repair a short in the IPB1 (IPB2) * wire between the PCM (C37 (C38) *) and the A/F sensor (Sensor 1), then do the repair verification.

   NO 

   The IPB1 (IPB2) * wire is OK. Go to step 3.

3. PCM internal circuit check

   -1. Reconnect the following connector.

   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) 6P connector: disconnected
   Test circuit	IPB1 (IPB2) *
   Test point 1	Rear A/F sensor (Bank 1, Sensor 1) 6P connector No. 5 (GRN)
   	Front A/F sensor (Bank 2, Sensor 1) 6P connector No. 5 (PUR) *
   Test point 2	Body ground

   Courtesy of HONDA, U.S.A., INC.

   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.

4. Repair verification (OBD STATUS check)

   -1. Turn the vehicle to the OFF (LOCK) mode.

   -2. Reconnect all connectors.

   -3. Exit the SCS mode with the HDS.

   -4. Turn the vehicle to the ON mode.

   -5. Reset the PCM with the HDS .

   Reset PCM

   -6. Do the PCM idle learn procedure .

   -7. Monitor the OBD STATUS for DTC P2238 and/or P2241 * in the DTCs MENU with the HDS.

   DTC Description	OBD Status
   P2238 Rear A/F Sensor (Bank 1, Sensor 1) IP Circuit Low Voltage
   P2241 Front A/F Sensor (Bank 2, Sensor 1) IP Circuit Low Voltage

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

   PASSED (P2238)

   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.

   PASSED (P2241)

   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 (P2238)

   Go to step 1 and recheck. If the PCM was updated, substitute a known-good PCM , then check the OBD STATUS again.

   FAILED (P2241)

   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.