04 k2500 I heared a bearing noise while driving with radio off. Found both front wheel bearings to be loose. Installed new hubs from NAPA that came with sensors. Frist drive after install, abs light came on after about three miles. The ABS light goes on and off intermitly. Cleaned and checked sensor conections to make sure they were tight with the harness. Had friend with Snap On code reader get codes c0040 and c0055. He sugested putting old sensors in new hubs. That made it worse with service brake soon message on dash. I have counted the teeth on the new hubs they are the same as old. The sensors make voltage when wheels are spun. Set the air gap on the new sensors to match what the stock ones have on the stock hubs. My abs light has never came on before changing the hubs. I am pull my hair out and may run out soon.

sounds like you covered everything. did you clean the sensors themselves, and make sure there was no rust or debris where the sensor sits in? Are the tone rings in the same place as on the factory ones? Maybe they might be a little more off set from the sensors.

The tone ring is postioned diffferntly, but the sensor goes in staiter than the stock ones looks like it should line up ok.

The tone ring is postioned diffferntly, but the sensor goes in staiter than the stock ones looks like it should line up ok.

Here are the codes:

C0035 Left Front Speed sensor
C0040 Right front Speed sensor
C0055 Rear wheel speed sensor circuit
C0245 EBCM Control Valve circuit
C0550 No Comm. w/ TCCM
C0201 ABS Enable Relay COntact circuit
C0110 Pump Motor Circuit
C0161 ABS/Traction Control system TCS
U1000 Class II Communication malfunction
U1300 Class II Data Link shorted
C0228 Wheel speed mismatch.
Borrowed from "Big Angry" here http://www.dieselplace.com/forum/showthread.php?t=289904&highlight=c0040 in post #7.


Your friend should have told you to check ONLY the right front sensor, since you code indicates a problem with right front (C0040). Since the lamp actually comes on, I'd suspect damage at the sensor (the black barrel shaped portion within the hub should be crack free, or it's harness, or possibly corrosion in the chassis harness plug (IIRC, the code is for loss of complete circuit).

Or maybe you got a bum one (or two). http://www.fixya.com/cars/e44369-wheels_cap_cover_hub


Since you've got a C0055, I'd also check the integrity of the wiring along the underside of the truck to the rear Xfer case mounted sensor, BUT, IMHO, when you figure out what's up with the Right Front sensor, the other code will go away.

x2 ^^^^

I used the truck to pull my rv on about a 200 mile round trip. The light was on when we left went off in about 2 miles back on in another 1/2 off again in a couple. It has not came back on since. Seems to have fixed it self. I had drove it maybe 20 miles before with the abs light on most of the time.