No wot shift in first

[slow600]

Fresh rebuild on my 94 4l60 with shift correction kit. All shifts firm and solid but when wot will not shift out of first. Jus stays on rev limiter until pedal lifted. Does not feel like it slips, jus feels like the PCM not telling it too shift. It's behind a stock 02 5.3 using the 02 ECM.

Being an older trans, it did not have provisions for the prndl switch from the harness. Could this be an issue? Happens when trans cold or up to temps. Any help appreciated.

[beingblueeyes]

dose the ecm command a 1/2 shift?

[kerrige]

Who is tuning it?

[farmtruc]

First of all, was it working before in this configuration?
'02 PCM. Etc

Can you record the vss and make sure the speedometer is working?
No vss signal, no shift.

[kerrige]

Shift tables are based off of simple rpm and MPH commands a wot. So like he said ^^^ to signal no reading no shift.

[farmtruc]

Just saw this the other day. Conversion freshly done. Trans redone but vss was bad or wire broken.

[slow600]

PCM shows mph. What's the easiest way to reset trans/PCM? Cables off and touching? Realized I never did anything since going from 3.42 to 4.88. Assuming that could be a factor? Trying easy stuff first, I don't want to pull the trans again.

[farmtruc]

so no retune going to 4.88's, that's the problem, the truck will never hit the mph 3.24's will, if no retune was done.

[slow600]

Speedo was re-calibrated and reads correctly but not an actual tune.

[farmtruc]

ah ok.

but still no tune, depending on how the speedometer was calibrated, the shift points could still be off.