Vehicle: 2014 Ford Fusion, FWD, L4-2.0L Turbo, Automatic Transmission
Problem: A DTC, U0401 (Invalid Data Received from ECM/PCM A) won't clear from all modules after recent collision repairs were made. The scan tool also reported an ABS/TCS steering module message. The vehicle had been in a rear-end collision and the front bumper was damaged as well. The body shop had already repaired all the damage and released car to customer. The malfunction indicator light (MIL) came on about a week later.
Details: The body shop tech performed a pin-point test but the results were inconclusive. The PCM and IPC both passed the “Self-test”. The tech also performed a PCM hard reset by touching battery cable ends together. The DTC and message was still present. After a quick call to ALLDATA Tech-Assist, the consultant suggested performing a quick inspection of the electrical wires and connectors in the collision-damaged areas.
Confirmed Repair: In about 15 minutes, the tech found the connector for the right/front wheel speed sensor (WSS) was damaged in the accident and had not been discovered during inspection and repair procedures.
The tech replaced the WSS connector and cleared the DTC. After a test drive, the code did not return and the MIL stayed off. The vehicle was fixed!