U0401: Invalid Data Received From ECM/PCM A
Description
NOTE:
This DTC is reporting a missing or invalid message from another module on the data bus. Do not install a new RCM as part of the repair unless directed to do so in a pinpoint test.
Action
CHECK for additional RCM and PCM DTCs. DIAGNOSE and REPAIR any DTCs that are retrieved. For RCM DTCs, REFER to the RCM DTC Chart. To diagnose PCM DTC, Refer to the appropriate Electronic Engine Controls article.