Yo guys,

I scooped up an 05 f350 for free couple weeks ago because owner just wanted to get rid of it due to issues. I've cleared every problem with the truck so far and I've now come down to the last issue... the ABS codes. These are the codes it's generating and a quick brush up on what they generally mean:

C1233 - open or missing LF abs sensor
C1446 - Brake switch circuit failure
B2900 - Faulty or mismatched VIN ABS module
U1900 - All kinds of possible problems including:
-> Faulty / intermittent ignition switch connections
-> CAN Bus wiring intermittently open/shorted to power or ground
-> Faulty / intermittent connection at PCM
-> Faulty electrical connections at ABS Control Module Faulty electrical connections at the instrument cluster
-> Poor connections at the trailer brake controller/trailer connector

Now driving the truck there is no problems with braking and everything feels fine, yet it throws these codes. I don't even know where to start at this point. I'm pretty sure this truck has not had a new ABS module placed in it, yet I can't say for certain. Given the U1900 and B2900 codes is there even anyway for me to diagnose these issues? I feel as though it needs a scanning tool to remedy these issues but I'm new to the truck so wanted to see if anyone has seen anything like this before.

Disclaimers:

1. A brake line to the rear wheels had bursted due to rust when I first got the car so bent up and flared a new line to the ABS module, and it leaks just a weeeee bit at the module disconnect point, but not enough to where I ever have to refill it.
2. I had a short in the Evap solenoid circuit when first got truck, replaced vent solenoid whose electrodes were completely corroded at both the connector and solenoid. In turn also replaced the fuse for that circuit which is run by the PCM

Not sure if anything I had done could result in any of the codes here, but I really don't want to take this thing to the dealer and get my wallet stolen so any help appreciated if possible. Thanks.

 

Test and fix the lf abs sensor first.. If the sensor is attached to a wheel bearing hub assembly it may be the wheel bearing is failing so check the bearing as well. A new wheel bearing hub assembly comes with a new abs sensor attached.
Check for a broken or disconnected brake switch at the brake pedal. Then clear and recheck for new codes.

 

Truck is already on stands brakes & hub off so I can't tell by driving it if hub is bad. Anyway to tell if hub is bad by looking at it?

 

You can mount the hub in a vise and check for roughness or in/out movement. Attach your old rotor to it backwards and you'll have a better grip to test.

 

Yeah I ended up just backprobing the abs sensor and the circuit was open so i'm 95% sure it's just the connector (had a little corrosion on it). I'll check the brake switch also but I don't believe fixing both of those would fix the B2900 and U1900.
Is their some kind of VIN on the abs module that would match the trucks? This way I can tell if the the module has been swapped out before. thanks

 

For that VIN mismatch code you’ll get that if you swapped out the ABS controller with a salvage unit. It has to be programmed to the truck. This can be done with FORSCAN and you can get all the “as built” data to input the correct hexadecimal codes from the motor craft website under free resources.
If you haven’t changed the module it may be broken. You Can grab one from a junk yard, usually for $30 (new are almost $900).

 

OP,
You have an F-350?