Mikelly

I'm gonna throw this out and see
what you guys recommend... I just replaced a motor in my
99Coupe. I had the whole drivetrain out of the car,
which required also a removal of the PCM and BCM. Got
everything back in and running great, but I'm getting
these U1016, U1064, U1096 codes, which are the PCM,
BCM, AND information center (gauges/ Dash) not
communicating. It is only sporadic, and doesn't effect
me driving the car. However, when I turn the A/C Fan
on high in traffic with other accessories on, I notice
the car idles slightly different... I'm running on a 7
year old Optima I had sitting from a previous race
car, that had ZERO use on it, so I'm wondering if that
may be an issue. But I'm also painfully aware of the
issues this car has with grounding, and your great
work in that area...

Any advice you guys can give would be appreciated. THe
Volts seem to remain around 12.7-13.6 when driving
with accessories and lights on, so I'm a bit confused.

Mike

boosted_z06

Sounds like a bad cell in battery, when voltage is low there is more changes of getting U codes.
My Z06 runs around 14.3 on average and never goes below 13.8

5 Liter Eater

I routinely get all three of these codes, as do others, but none of them make any matter. They are all standard error messages from what I've heard.

My battery is fairly old too and may be due for replacing. I average ~13.8 while driving. I also get random C1226's which are LF wheel speed sensor and have heard that a low/old battery can cause that too.

Rex99Coupe

Same three codes my 99 gets. My volts are 14.2 while cruising on the freeway. Car runs fine.