After finally finding a used ebcm for my 2000 C5 Im now having problem with abs and traction control lights coming on..The codes are 1225C and 1281C..Good thing is these will reset as compared to when the old ebcm said no communication.....Easy fixes or big problems?

 

1st see if the rear tire size height is correct and the axle ratio is correct in your tune---If its not you'll get ABS TC codes---ALSO if you have aftermarket tire sizes you must keep the split from the front to rear tire sizes very close to 1" ( the rears have to be close to 1" taller than the fronts) or you may get codes
Typically ABS and TC codes are a result of faulty sensors or fouled pigtails on your individual wheel sensors---
The ABS system uses wheel sensor speed to control the wheels from skidding during a hard stop
The TC system uses wheel sensor speed to control the wheels from spinning durung acceleration

 

DTC C1225 is LF Excessive Wheel Speed Variation
wheel speed sensor.... Code C1225 indicates that the left front wheel speed sensor is either sending a bad signal or no signal. Start by checking the connections. The wheel speed sensors are integrated into the wheel bearing/hub assembly pictured below. The wire coming out of the back is the connection for the wheel speed sensors. Verify that the connector are not broken, damaged, or corroded in any way. Pay particular attention to the female end.
The wire coming out of the wheel speed sensor connects to and 18" jumper harness, then to the main harness. It is very common for people to have a weak female pin in one of those connections. If all of that checks out good, swap the jumper harness from side to side. For example if the left front is bad, swap it over to the right front. And install the good one from the right front to the left side. Then clear the trouble code. If the trouble code is now on the right side, you know the wire harness is the problem. If the code is still on the left side after swapping the jumper harnesses, you know the problem is inside the wheel speed sensors.
If all the wires check out good, it's time to take a trip to Auto Zone for a new set of bearings. You can buy replacement AC Delco bearing from your dealer if you want to, or get the exact same bearing in a different box for half the price (~$150) from Auto Zone.

DTC C1281 Steering Sensor Uncorrelated Malfunction
Steering Wheel Position Sensor may need replacing...check for good connection first...then to replace...
Set the steering wheel straight, so that the front wheels are
straight, and try hard not to turn it during the whole process.
- Disconnect the wire from the sensor.
- Disconnect the topmost U-joint under the hood (probably
the "hardest" part)
- Pull the knee bolster and its support bracket
- Get the new steering sensor - leave the pin in it!!
- Remove the 4 bolts that hold the steering column to the car.
- Pull the column into the car just enough to clear the sensor.
Rest it on the cross member under the dash, but don't pinch
any wires.
- Swap in the new sensor - note alignment when removing the
old sensor - leave the pin in the new sensor!!
- It helps to have a helper slide the column back in while you
reconnect the U-joint under the hood, but I did this myself
with several back-and-forth's. Watch for pinching wires.
- Reassemble.
- Pull the pin in the new sensor.

OR>>>>have your mechanic do it ............part runs $175 approx