This is why I only have manuals

So my grandparents are gone for the week, I'm watching their house, grandfather says I could drive his truck if want, it's a 2001 2500 24 valve Cummins, auto.

So I take it to the store the other night, just fine. Hopped in it to take it to work the next morning and it feels like it's stuck in 2nd when starting out, doesn't shift into OD and the TC doesn't lock up

I pulled the codes

P0500 Vehicle Speed Sensor 1 Circuit, or No Vehicle Speed Reference Signal 1 (speedo works fine)

P0622 Generator Field Control Circuit (Constant 14.1 volts while driving with headlights on)

P0743 Torque Converter Clutch Circuit Electrical

P0753 Shift Solenoid "A" Electrical

P1765 Transmission 12 volt supply relay control circuit

Any ideas how I go about tracking this problem down?

I should also mention the tranny was recently rebuilt with an ATS billet converter and it has some sort of Banks package on it (intake, exhaust, ram horn manifold, no idea what "chip", it's just a simple on-off switch) and it's got a Banks exhaust brake as well.

 

just some quick research, but it looks the the P0622 can cause all the other ones to occor. I would start with that.

SYMPTOM
P0622-GENERATOR FIELD NOT SWITCHING PROPERLY

WHEN MONITORED
With the ignition key ON and the engine running.

SET CONDITION
When the PCM tries to regulate the generator field with no result during monitoring.

POSSIBLE CAUSES


Intermittent condition
Generator field source (+) circuit open
Generator field driver circuit short to ground
Generator field driver circuit open
Generator field coil open
Generator field coil shorted
PCM