Bench testing GPIO for 4l60e

A forum for discussing applications and implementations of the MegaShift transmission controller code for the GPIO from B&G. This can control up to 8-speeds and 6 shift solenoids (plus a 16x9 table for controlling a PWM line pressure valve). It has manual and fully automatic modes (16x9 load x speed table), with under and over rev-limit protection, and full data logging of all inputs and outputs (among many other abilities). A TransStim to test your completed board is also available.
jdrapersys
Posts: 12
Joined: Wed Mar 16, 2011 10:20 am

Re: Bench testing GPIO for 4l60e

Post by jdrapersys »

Lance,

All the voltages an resistances check out and if I ground the R60 jumper the shift function works. I fear I have a faulty board. There is what appears to be a loose trace on the top of the board. If the trace were not loose, that is slightly raised on the heat sink side if Q17 and Q18, it looks like it would go along the heat sink side of them and then curve around the R60 side of Q17 to the R60 donut furthest away from the heat sink.

I have never tried to repair something like this and am concerned that even if repaired that it would break later in the car. So if you agree I propose soldering an insulated jumper on the bottom of the board from R60 ( the donut nearest the heat sink? ) to the AMP15 pin on the bottom of the board. Alternatively I could start all over since I do worry that something else may be wrong with the board. Although it is possible that I did something to tear up that trace, I doubt it. This is the 6th board from dyiauto that I've done and putting that zener in backwards was my first mistake in assembly. Then there is the cost of a new board and all the work of assembly, although a second board is somewhat faster to assemble.

Again many thanks for you help,
John
Bernard Fife
Posts: 1696
Joined: Fri Apr 04, 2008 1:28 pm

Re: Bench testing GPIO for 4l60e

Post by Bernard Fife »

John,

I see the trace you are talking about on a board here. Is it still covered with the green solder mask, or is it bare?

You can jumper on the bottom of the board. That's what I would do if the board was mine. If you solder it on well and then crazy glue the insulated portion to the board in one or two spots that ought to support it well (if it is just the right length it probably wouldn't even need support, but it doesn't hurt).

Once repaired, there shouldn't be further issues (I have run boards with all sorts of jumpers like this for years in my vehicles without any issues to date).

If there is a manufacturing defect, we would like to find out as much as we can about it. At your discretion, we could send you a new board for free (but you would still need all the components, of course) if you want to send yours back to us. Alternatively, do you have a digital camera that you could take a close up picture of the damage with, and post the picture? That would help a lot.

Lance.
"Never wrestle with pigs. You both get dirty and the pig likes it." - George Bernard Shaw
jdrapersys
Posts: 12
Joined: Wed Mar 16, 2011 10:20 am

Re: Bench testing GPIO for 4l60e

Post by jdrapersys »

Lance,

I have a good photo using a magnifying glass, but I was unable to attach it to this post. So I put here
https://www.facebook.com/album.php?aid= ... b4bdba6a3b
in a (so far) one picture album on my facebook wall. The trace is no longer exactly where I first saw it. I managed to curl it's end around the R60 jumper and solder it there.

I can up and down shift manually now. Although it was interesting that my mileage (MPG) was the same no matter what gear I was in. So I if I'm correct, to complete testing the inputs, I only have EGT1, EGT2, GPI1, and GPI3 to do. Any suggestions?

Very best regards,
John
ForumAdminTeam
Site Admin
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Re: Bench testing GPIO for 4l60e

Post by ForumAdminTeam »

John,

I will have a look at the photo, thanks.

The MPG is a bit funny on the bench. There it only depends on the rpm, speed and load, and since the rpm, doesn't change as you change gears, the MPG doesn't either (n the real world, both the kPa and engine speed would change after most shifts, of course).

Lance.
jdrapersys
Posts: 12
Joined: Wed Mar 16, 2011 10:20 am

Re: Bench testing GPIO for 4l60e

Post by jdrapersys »

Lance,

I also have questions on adding LEDs to the board. Is adding diode Da needed to ensure the AMPseal pin goes to ground when an Rb and an LED is added? How is Vref or 12V connected to Rb? Duh, as I was writing this I now see that I need a 3 pin jumper or I can just jump from a cut off lead. I have 330 ohm resisters and 2V yellow LEDs should I use 12V or 5V to light them?

Finally, in testing who goes to ground - when, I have GPI1 for 1st, GPI1 and GPI3 for 2nd, GPI1, GPI3, and GPI2 for 3rd, and all four for fourth. Did I do something wrong to get 1 and 3 activated for 2nd gear?

Best,
John
jdrapersys
Posts: 12
Joined: Wed Mar 16, 2011 10:20 am

Re: Bench testing GPIO for 4l60e

Post by jdrapersys »

Lance,

On the MPG: is it possible (perhaps by me) to change the calculation in TunerStudio to be based on say a 0.1 second delta t's, with a fuel flow numerator ( number of squirts by pulse width by injector flowrate) with a delta miles denominator. I though all the required information for fuel flow was available via the CAN.

Best again,
John
Bernard Fife
Posts: 1696
Joined: Fri Apr 04, 2008 1:28 pm

Re: Bench testing GPIO for 4l60e

Post by Bernard Fife »

John,

Are you referring to adding an LED to the GPOx circuits? For those, you don't use Da. See: http://www.msgpio.com/manuals/gpo.htm#led You can use either 5V or 12V to drive the LED. The key consideration is to limit the current through the LED to safe levels.

For example, if the LED can carry 30 mA max and drops 2.0 Volts (find these specs in the LEDs datasheet, yours are likely different), then the resistor needed is:

R = V/I = V/0.030

- for 5V, the voltage drop in the resistor is 3 Volts (5-2), so the resistor should be at least 3/0.030 = 100 Ohms.

- for 12V, the voltage drop in the resistor is 10 Volts (12-2), so the resistor should be at least 10/0.030 = 333 Ohms.

For the power rating for the resistor, P = I*V = 0.030*V
- for 5V, P = 0.030*3 = 0.090 Watts (so a 1/8 Watt will work fine)
- for 12V, P = 0.030*10 = 0.300 Watts (so use 1/2 Watt)

There is more on this here: http://www.msgpio.com/manuals/gpo.htm#ledchoice

The input lever pattern for the 4L60E is shown here:http://www.msgpio.com/manuals/mshift/operation.html about 1/2 way down the page

Yes, I believe you can write a formula in the INI to do the MPG calculations, I believe. You need to know the injector flow rate and number of cylinders, the opening time, the engine rpm and injection scheme (number of squirts and alternating/simultaneous), and the speed.

If you have those (and they ought to be available to TS) then you can calculate the fuel consumption.

Lance.
"Never wrestle with pigs. You both get dirty and the pig likes it." - George Bernard Shaw
jdrapersys
Posts: 12
Joined: Wed Mar 16, 2011 10:20 am

Re: Bench testing GPIO for 4l60e

Post by jdrapersys »

Lance,

I would still like to throughly bench test. If you don't have enough interest to have more boards made, could you put me in touch with some of your old customers who might want to sell their Trans-Stim? Or failing that could I see a more detailed schematic so I could try to make one with a prototyping board? I tried blowing up the picture of the board, but I was still uncertain about somethings. Like how to simulate line pressure so I can get auto shifting to work past 2nd gear. Also why does it appear that the LED cathode goes to pin E, which in the wiring diagram is fused to +12V.

Many thanks in advance,
John
Bernard Fife
Posts: 1696
Joined: Fri Apr 04, 2008 1:28 pm

Re: Bench testing GPIO for 4l60e

Post by Bernard Fife »

John,

I am planning to get 50+ trans stim boards made by next month. These will be offered on a first-come, first serve basis.

The schematics for the new board have been changed, and I haven't had a chance to post them yet (working on code instead at the moment).

You can simulate any of the signals fairly simply with pots for the 0-5V analog signals, switches for the on/off signals, and LEDs w/ current limiting resistors for the outputs.

You don't need line pressure to simulate auto-shifting, you need a 0 to 5V load signal (like from a MAP), or a CAN connection to MS-II. A 10K pot with a 5V supply will work for this.

I am not sure what you are referring about the cathode connection.

Lance.
"Never wrestle with pigs. You both get dirty and the pig likes it." - George Bernard Shaw
jdrapersys
Posts: 12
Joined: Wed Mar 16, 2011 10:20 am

Re: Bench testing GPIO for 4l60e

Post by jdrapersys »

Lance,

I would also be interested in renting a stim from someone. I would only need it for a week or so.

With regard to my cathode question, perhaps I should restate: Are the labels Pin S and Pin E interchanged in http://www.msgpio.com/manuals/mshift/4L60E_stim2.gif? Because in http://www.msgpio.com/manuals/mshift/4L ... matic1.gif Pin E is connected to the external +12V source and the connector for the 3-2control solenoid is labeled Pin S.

Then on the right hand side of http://www.msgpio.com/manuals/mshift/4L60E_stim2.gif should the bottom be connected to AMP33 also labeled Pin D and the top connected to +12V (Pin C)? And for stim purposes should the 1N4001 diode and 4.7 5W resistor be included in the set-up? As in http://www.msgpio.com/manuals/mshift/4L ... ematic.gif

Also with regard to http://www.msgpio.com/manuals/mshift/4L60E_stim1.gif The LED polarity seems to conflict with http://www.msgpio.com/manuals/mshift/4L ... ematic.gif . Is the schematic for the LEDs purposely different for the stim because AMP7-AMP10 are not to be connected?

Then for http://www.msgpio.com/manuals/mshift/4L60E_stim3.gif could you tell which wires from the AMP connector go to the left side of the 20K resistor and which AMP connector pin connects to 00-5V out.

Again many thanks for all you patience and help.
John
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