DTC U0401

DTC U0401  : Invalid Data Received From PCM

DTC (A/T)

1. PGM-FI system DTC check

   - 1. Turn the vehicle to the ON mode.

   - 2. Clear the DTC with the HDS.

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

   - 4. Turn the vehicle to the ON mode.

   - 5. Check for Pending or Confirmed DTCs in the PGM-FI system with the HDS.

   DTC Description	Confirmed DTC	Pending DTC	Freeze Frame

   Are any DTCs indicated?

   YES 

   Go to the indicated DTC's troubleshooting in the PGM-FI system - Refer to: Fuel and Emissions Systems DTC Troubleshooting Index (KA/KC models) (2016), or Fuel and Emissions Systems DTC Troubleshooting Index (2017 2018), or Fuel and Emissions Systems DTC Troubleshooting Index (2019 2020) .

   NO 

   Go to step 2.

2. Problem verification

   - 1. Test-drive the vehicle for several minutes under the same conditions as those indicated by the freeze data.

   - 2. Check for Pending or Confirmed DTCs with the HDS.

   DTC Description	Confirmed DTC	Pending DTC	Freeze Frame
   U0401 Invalid Data Received From PCM

   Is DTC U0401 indicated?

   YES 

   The failure is duplicated. Update the PCM if it does not have the latest software , or substitute a known-good PCM - Refer to: PCM Removal and Installation (2014 2015), or PCM Removal and Installation (2016 2017 2018 2019 2020) , then recheck. If this DTC goes away and the PCM was updated, troubleshooting is complete. If this DTC goes away and the PCM was substituted, replace the original PCM - Refer to: PCM Removal and Installation (2014 2015), or PCM Removal and Installation (2016 2017 2018 2019 2020) .

   NO 

   Intermittent failure, the system is OK at this time. Check for poor connections and loose terminals between the PCM and the TCM. 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.