new2chevy

hey guys

My 4L60e sometimes doesn't downshift when in "D" and when I stomp the gas when I am going about 25-40 mph. I hate that.

Is this fixable through tuning the PCM and shift points and stuff?

It downshifts and gets going very nicely when below 25 mph and stomping the gas pedal.

Hopefully this can be addressed with tuning software and a laptop.

Also, is it OK to just downshift manually and stomp on it? I notice it does not want to manually upshift into 3rd, also.

thanks to anyone who helps

Injuneer

Have you scanned the PCM for codes? There are a number of tranny codes, and they do not turn on the SES light.

new2chevy

No not yet.

I am still waiting for tunercat to get back to me about authorizing my datamaster program. They are not replying back to me.

new2chevy

I think the PCM is pulling timing at WOT and it is really noticeable at highway speeds. I think it is detecting knock from my headers.

I need to get the LT4 knock sensor module.

My tranny may not be totally up to speed, either, which doesn't help.