MSgpio.com read only forums (Jan.15,2018)

Hi,

On my 4L80E the upshift pressed light is always on. Is this normal? It does say it is in auto mode as soon as the controller fires up and stays there.
I also cannot find any schematics on how this cirquit is supposed to work, nor does it mention anything in the build manual. Am I overlooking something?

VSS cirquit is also pretty buggy. I've changed R45 from 300K to 150K to 100K and now on 47K. Still issues though. I've changed firmware to V 2.128 and now on 2.200 but still not very stable. Tried new sensor, no go. I measured the air gap between sensor and teeth and cam up with a value of 3mm, is this about right? It wat even 4mm with the old sensor. Seems a lot to me.

marcars,

Your upshift button is shorted to ground, either internally or in the wiring harness (or switch). The upshift circuit is VR2, and should be built as a digital input. The schematic is here: http://www.msgpio.com/manuals/vr.htm

Does the VSS input work properly on a stim?

Lance.

Lance,

I didn't populate VR2 as I don't use the up and downshift buttons (yet). Even if I pull the respective jumper, PT6 VR2 in this case, the situation stays the same. I've measured between PT6 and ground to check for a ground path and no, infinitive.

marcars,

You need to make sure that the circuit is pulled up to to a nominal 5 Volts (actually it needs to be over ~3.250 Volts, but 5 is better). Otherwise the processor thinks that output is grounded, and asking for a shift.

You can do this on the board with a few resistors and jumpers, but you cannot leave the circuit unpopulated. For the components you need to add, see step J. (sub-steps 1, 4, 5, and 6) here: http://www.msgpio.com/manuals/mshift/assembly.html.

Lance.

You're absolutely right. Works a charm now.

I had missed the general GPIO build part. Oops.

marcars,

Great, I'm glad it's working now!

Lance.