Hi everybody,

I am having a problem with my 09 F-150. The lights for ABS and Brake are on constant, and I am not sure what is causing the issue. I took my truck to the local auto store to pull the following ABS codes:

U0028
U0121

They didn't have any information on either of these codes. I am thinking that it might be a bad fuse (or at least that is what I am hoping for). If anyone else has any information about these codes, I would greatly appreciate it. From Google searches, it looks like this code pops up fairly often.

Thanks in advance!!

 

Additional issue, I took my truck to the tire shop to look at why I have a Tire Pressure Sensor Fault. Tire shop said that all sensors are registering so they can't find the issue there.

 

Have you got any high-powered devices in your truck? Like a dashcam or a phone charger that's always plugged in?

 

I read about that causing some strange issues. I did unplug it to see if that would fix it with no positive results. Having said that it was for only about 15 minutes. I'll have to unplug it for a full day and see if that makes a difference.

 

I doubt a day is long enough to see if this is the issue for the tpms, because it's hard to prove a negative. I had the tpms issue, but it was so infrequent that I couldn't be sure of anything. So, changing how I had accessories plugged in also took a long time to analyze. Weeks, really.

Not so sure about the other DTCs. But, those are also communication errors rather than serious issues, so might be the same cause.

 

Update: I have a wireless charger in my truck. I unplugged that, and it seems to have stopped the TPS fault.

 

Trouble codes that start with U are usually communication problems on the network. U0121 is a loss of communication with the ABS module.

 

I have my 2016 with the same issue. Scanner are not able to read the ABS module, what could be? relay or fuses? or module is bad? any help will be appreciated. thanks