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

NOTE:  Before you troubleshoot, review the general troubleshooting information - Refer to: How to Troubleshoot the Fuel and Emissions SystemsHow to Troubleshoot the CVT System(CVT System) .

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) 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):

  - 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 connectors.

  PCM connector C (51P)

  A/F sensor (Sensor 1) 4P connector

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

  Test condition	Vehicle OFF (LOCK) mode
  	PCM connector C (51P): disconnected
  	A/F sensor (Sensor 1) 4P connector: 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:

  - 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

  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) .