DTC P2238

DTC P2238  : A/F Sensor (Sensor 1) AFS+ Circuit Low Voltage

NOTE:  Before you troubleshoot, review the general troubleshooting information .

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 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. 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 (AFC1 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 B (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 B (51P): disconnected
   Test point 1	A/F sensor (Sensor 1) 4P connector No. 1
   Test point 2	Body ground

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

   Is there continuity?

   YES 

   Repair a short in the AFC1 wire between the PCM (B43) and the A/F sensor (Sensor 1).

   NO 

   The AFC1 wire is OK. Go to step 3.

3. PCM internal circuit check

   -1. Reconnect the PCM connector B (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. 1
   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 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) .