Hello, I have searched this forum for help with my trans and came up empty , so I started this thread for help.

2004 Silverado 5.3 4l60e swap donor.

All gears act as I they should expect 4th/od
Pcm is not getting a signal for forth gear.
HP tuners and also a Snap on tuner can command 4th and it shifts flawlessly.

pcm is not even seeing 4th gear in the scanners. Would this be the manifold pressure switch or a wiring issue.

Thanks for helping the newbie out.

 

What Model-Year is the 4L60E Transmission?
If anything is not Stock inside the Transmission... what is it?

What PCM/ TCM, and Wiring-Harness is controlling the 4L60E Transmission... if OEM, what Model-Year?

What PCM and Wiring-Harness is controlling the 5.3L Engine (Gen-III or Gen-IV)... if OEM, what Model-Year?

Does the 4L60E Transmission have the Torque-Converter locking-up, while in 3rd-Gear?
What Torque-Converter is being used?

 

It was a complete dropout motor,trans , pcm and harness out of an O4 Silverado.

converter is locking in 3rd.

@vorteciroc