Bench testing GPIO for 4l60e

[mspinale]

Hello,

I finished building a v2.10 board today for my 1995 Firehawk. (followed build instructions at /manuals/mshift/assembly.html)

I'm trying to test this as much as possible before install. I was able to flash the board with the 1.100 s19 file (http://www.msgpio.com/manuals/mshift/Mo ... 00.abs.s19) and connect with Tuner Studio. I found Lance's project (http://www.msgpio.com/manuals/mshift/MS ... roject.zip) and used it along with the 1.100 ini. AMP connector wiring is done per http://www.msgpio.com/manuals/mshift/wiring.html

Since I have only power applied and all grounds grounded, I expect some problems or at least some misleading values. However, there are some strange behaviors such as shift from 1 to 4 after about 90 seconds. CODES indicator illuminated (have not figured out how to view these just yet) and BRAKE ON is lit when no 12v or 0v applied to pin 3. These symptoms make me wonder if i have done something incorrectly. The "UpShift Pressed" indicator also comes on after about 90 seconds...

Does anyone have what they consider or would recommend as a basic bench test procedure that one could follow to validate their build?

Can't wait to see how this works with my MSII and supercharged 383 Hope to drive it to work one day per week THIS summer if all goes well.

Any pointers MUCH appreciated.

Regards,
Marc

[Bernard Fife]

Marc,

With the inputs unconnected, the ADC (analog to digital converter) values will slowly rise, and all sorts of weird behaviour can occur. So I wouldn't assume anything is wrong under the conditions you are testing (there might be things wrong, but you couldn't tell wothout everything connected).

I have designed a stim for trans testing (that simulates all the essential inputs and outputs), and distributed all of these with the test boards. There is more info here: http://www.msgpio.com/manuals/mshift/4L60Estim.html If there is enough interest, I will get another run of stim boards made for people to use. However, I have offered this before, and received no significant interest.

Lance.

[mspinale]

Thanks for the quick response Lance.

I'm interested in the stim but in my case it may be faster to just wire it up to the harness for some additional tests. The harness is all marked and ready to go so with any luck I can patch it in for testing over this weekend.

If things don't go as planned (and often it seems they don't), a stim may be needed/desirable to troubleshoot build issues on my part.

Thanks!
Marc

[tjabo]

I continue to be interested in a MegaShift Stim Lance.

How much would you need per board to do a small run of them?

Thanks,

Thad

[Bernard Fife]

Thad,

If 20 people committed to buying these boards, they would be about $14 each for bare boards (and less than $10 each if 50 were interested), then the BOM components would also be required (http://www.megamanual.com/mshftstimbom.htm).

Lance.

[mspinale]

I finally wired the GPIO into the 1995 Firebird and am trying to work through a few things. (CAN is not yet connected to MSII however)

I could really use some pointers.

1) The Brake sense circuit does not appear to be working. The signal goes low when power on and brake depressed. I toggled the logic in TunerStudio appropriately. I placed a logic probe in AMP PIN3 and see the logic change but no update in TunerStudio. I suspect that something is wrong with the circuit. Anyone have any ideas as to what to check?

2) Current Gear was incrementing during bench testing. This stopped. With the key on, Current Gear stays fixed on 1st gear as opposed to "0". Should this be 0 in park with key on as opposed to "1"?

3) Trans temp is off the charts at 236 degrees. My first guess was that this was a problem with a missing sensor ground. The GM pinouts show no special ground for this. VSS does have a sensor ground however. BUT: I grounded AMP PIN 30, the temp input and saw no change through TunerStudio. The value floats around +/- 1 degree. Perhaps I repeated the same error on the board in a few places? Any thoughts as to what to check?

I have a nice heavy duty 5 Ohm 15watt resistor on hand that I could use with the correct diode for flyback between C & D. Would 5ohms be within permissible tolerance?

Should anything be jumpered on J2 or is this just for test (aside from the hard-wired jumpers shown in the build guide)?

Here are the outputs from TunerStudio with Key On, car in park not running:

• Speed 0, tach 0, trip & load 0
  PWM shows 100%
  SP1 & SP2 OFF
  No Codes
  4WD RED
  Auto Mode - Blue Text on Red
  In Drive Blue
  Downshift Pressed - Blue Text on Green
  Upshift Pressed - Blue Text on Green
  TCC Off - Black text on Green
  Brakes On - Blue text on Red

I am keeping track of all the connections / details. Once this works, I will publish these. Until then, if anyone is interested in 1995 F-Body, PM me.

Thanks!

[Bernard Fife]

mspinale,

If this was mine, I would pull the jumper for AD7/GPI4 (on the 25x2 header) and look for an appropriate brake signal on the pin closest the Ampseal connector. The signal must be around ~3.25 V (but not more than 5.6V) to be 'high' and below about 1.75 Volts to be 'low'.

I would tackle your issues one step at a time, since the controller needs good inputs to have useful outputs.

Lance.

[mspinale]

Hi Lance,

I made the two hard-wired jumps only on the 25x2 (AD1-GP12 & VB1-PT7).

Could the answer be that I simply missed setting additional default jumpers on the 25x2? I did not see or missed that step!

Thanks so much!
-Marc

[mspinale]

Hi Lance,

I was laughing out loud a second ago when I realized (thanks to your post) how simple the solution was! It now seems obvious that all of the jumpers should be set for circuits used for 4l60e (table on pg1 of build instructions)? I wondered about J2 but never saw anything clear on this step.

I see this working now and will test each signal to be safe before adding jumpers.

Thanks again!
Marc

[Bernard Fife]

Marc,

It's an easy thing to miss, I have done it myself occasionally. I will add that bit to the manual!

Lance.