Drive DTCU0401 – Modules aren't talking to each other
Invalid data received from ECM/PCM A
Network and modules · generic OBD-II code
Drive it only if you have to, gently and not far. Get it fixed right away.
Check this first
Check the battery terminals and grounds first – weak power causes most network codes.
What usually fixes it
In the order a good shop checks them. Typical total: $114–$1,906 at $130 an hour.
Battery, terminals and grounds
Low voltage drops modules off the network.
Network wiring
A damaged wire between modules.
Failed module
One module that has stopped answering.
This is the advice for this family of codes – Drive DTC doesn't have a page written for this exact code yet.
What the vehicle can tell you itself
A stored code is a headline, not the story. The vehicle also holds the conditions when it happened, how close the part is to the limit it fails at, what the fuel trims are doing, and whether the fault is still happening right now. Drive DTC reads all of it with a USB adapter and a Windows PC – and it can't change a single setting on the vehicle.
See what your vehicle says about U0401
Codes in plain English, what usually causes them, what the repair costs, and whether it's safe to drive.