I have a 03 cummins that has been giving me problems. I have had truck almost 2 years and it would shut off under hard full throttle acceleration and throw the p2146 code when it was cold. Didn't have problems all summer. Now that it's winter it is slowly getting worse. Under normal driving it will throw check engine light and idle irrationally. Truck also will drop rpms at a steady speed and rpms fluctuate and rail pressure does also. Then it idles up and runs fine. Now truck just shuts off under normal driving p2146 code.

 

P2146 Bank 1 (Cylinders 1-3) Shorted High Or Low

Likely a bad injector solenoid in bank 1, cylinder 1-3. Ohm check them if it is doing it contantly and you will likely find it. A DVOM with .5 sensitivity should read .5 across the studs with wires disconnected. If it is higher thats the culprit.