NEED HELP 1995 GMC C1500 5.7 TBI REBUILT 4L60E Limp Mode No Codes Stuck In 3rd Gear

[94GMCK1500]

I just had my 94 GMC 4L60E rebuilt. Guy says full rebuild with all new GM parts and solenoids.. Drove it home, it seemed little sluggish but I knew it needed a tune up and just had the intake done so figured timing may be little out.

Did full tune up with AC Delco, plugs, wires, rotor and cap. Fuel filter was done less then 3k miles. I got codes popping up when I went to set timing... 14,28.33.42.54.66. I unplugged what I was told is the ignition wire ( actual name slips my mind )... The timing was out, I set it to 0 degree as it's called for... I cleared ecm by unplugging battery... I now have the codes 42, 66... My transmission feels like its in limp mode... I haven't checked the + (pink) wire for power yet, doing that tomorrow...

Would it safe to say that it's the ecm if the pink wire tested fine...? Or am I missing something else ? I gave much as I feel is enough info... Have any questions, I'm open to answering what I can...

 

[1997]

from what i googled, https://www.troublecodes.net/gm/gm-92-95-ck-pickup/

code 42 = = Cause

Ignition control module (ICM) – electronic spark timing (EST)/ignition control (IC)/bypass circuit malfunction

Wiring open circuit/short circuit to ground, ICM, ECM

couldn't see code 66.

i think you need to do more troubleshooting before thinking about replacing anything at this point.
Clear the codes again and see if they come back again. work on those 1st.
the ECM is usually the last thing to replace.....