BigStuff3 Shift Problems

[TY69SS]

We are having problems with the 4l80e transmission been controlled by BS3. We have checked all wiring and fuses, checked the configeration tables and they are correct. When you drive the car goes into reverse and foward but it will not shift any of the gears.

When we look at the shift table the ellipse moves and crosses the green line and the computer reads like it went into 2 and then third and forth but there is no shift from the trans.

Everything seems ok but no shifting.

Please any help would be appreciated.

[Steve Chryssos]

Won't upshift out of 1st gear? There are quite a few potential sources to this issue including internal mechanical transmission problems or a bad VSS sensor. But for starters, disconnect the signal wire going to the speedo. Test with rear wheels on jackstands to minimize load during testing. Also confirm accuracy of TPS calibration, but my money is on the speedo. If the speedo is un-calibrated or mis-calibrated, it can confuse the TCU.

Note that I don't have any personal experience with BS3 tuning. Recommendation is based on similar issues with all other brands of controllers except for HGM Compushift where speedo calc is not tied directly to VSS output.