Custom Trans Indicator Gauge in TPRT

[Scrufdog]

I see that you can read the 3 Range settings and they change per shifter selection. Is there a way to create an individual gauge that shows P R N D 3 2 1, but calcualting/translating the Range outputs? The reason I ask is to plan ahead in case I do a custom dash and run full LCD.

Thanks

[buddrow]

What transmission are you using? If it is an electronic trans there are a couple of ways depending on the model.

Buddrow

[Scrufdog]

95 4L80-E in The Burb

[buddrow]

That should be fairly easily done with the Manual Lever Position Sensor Mounted outside the trans. The degree of simplicity depends on your electronic aptitude and the equipment you plan to use, i.e. LCD.

Buddrow

[lionelhutz]

A 4L60e has internal gear selection switches fed back to the PCM through the harness. I haven't looked at any wiring but I'd have to believe the 80e has the same thing. As long as the PCM will send the info on the OBDI port, the gear info should be available along with all the engine data.

[Scrufdog]

I'd like it to work an adx file, that way all useful data for a standard dash is on one screen with one piece of software. I can think of a few ways to make a calculation to do it, but it seems adx files are very structured as to what calculations can be done by TunerPro.

I'm thinking something along the lines of...

Reading the value for Range 1 and converting it to a decimal, X*100
Reading the value for Range 2 and converting it to a decimal, Y*10
Reading the value for Range 3 and converting it to a decimal, Z*1

Adding X+Y+Z=T and ending up with a decimal number, eg. 100, 110, 011, etc...

Then comparing the value to a list of definitions to display the proper letter on the gauge, eg. P R N D 3 2 1. This would likely use a bunch of if/then commands. Something like if T = 101 then display R (or whatever it would be, dont have the chart with me)

The same thing could be done using binary or hex if needed. I'm kind of surprised no one has done this yet, seems like a convienant thing to have if your using TP as a main dashboard, which I've seen here and there.

......

Otherwise I could just do the mundane way of wiring into the shifter selector and use external LEDS and a normal indicator cover, but that seems... blah. :)

[buddrow]

As lionelhutz mentioned there is a "sensor" internal to the 4L60 as well as the 4L80 and most late model GM front wheel drive transmissions. They are on off type switches which only work when the vehicle is running, fluid pressure applied(not a problem in most cases but cant be used for neutral safety switch). The trans fluid pressure switch has 3 switches which the pcm uses to determine which gear position the manual lever is in as indicated by fluid pressure acting on the switch. The pcm uses a logic table to determine gear range based on the voltage(12Vdc closed or 0 Vdc open). Anywho, If you only want the gear indicator to be correct when the engine is running you can tap into the harness from the trans and fedd your circuit fromthat or you can accept the data stream from the pcm and interpret the range from the info provided within but thats a lot more work. Ideally you would use the manual lever position sensor mounted externally on the shift shaft(manual lever) as you're input source.

As for the dash, You may be able to employ the digital display(not dial gauge) option to display the selected gear range but you may be relegated to using the bitmask section and setting it up that way. I haven't completed my adx file for my transmissions controller project yet, but it currently includes MPH, pressure solenoid duty cycle, throttle position, engine RPM and a bitmask each for the shift solenoids and torque converter solenoid state. I hope this has some how helped you and if not feel free to comment or question at will. :)

Buddrow

[Scrufdog]

well, if TPRT cant do it, I could always tap into the 3 wires on the pressure switches and run the signals through some logic gates and diodes (input/output filtering) to produce 7 individual outputs that could be connected to LEDs.

[lionelhutz]

Here are a couple of screen shots from the dash in the $EE-16188051-V3.8.adx file. You can see the gear indicator changes from OK to YES or the P/N indicator changes from In Gear to Park-Neutral. I'm sure you could do similar with the 4L80e. This may not do what you want though because the internal switches don't distinguish between park and neutral.


trans3rd.PNGtransNeut.PNG

[Scrufdog]

mine has a similiar indicator in it, not bad, but would like more detail

[Scrufdog]

looking at the dash wiring, I see that those 3 signals are sent to it. So I figure I can just grab a spare dash from the junkyard, isolate power, ground, and the 3 signals, and cut that part off the spare, having a small piece of circuit board already done.

I'd rather do it with TPRT, but this would work too.

[gregs78cam]

It is not hard at all to replace one item in the data stream with another. I did a write up somewhere. I have my dash set up to show which forward gear it is in. Look at the two adxs for the trans and then just put the items you want into the engine .adx.

http://www.gearhead-efi.com/Fuel-Inj...hlight=hacking

Just focus on the idea behind the first post. We were working on the older '7747, and had very little data to put into an even smaller data stream. The '7427 is much easier.