LuckiNite

If this was addressed before, I apologize. I looked through the forums and did a search but nothing was mentioned.

The overhead display in a Chevy Blazer shows the outside temp, average MPG, current MPG, estimated driving distance, and a few other things.

Has anyone (or does anyone know) written a guide or (hacked this themselves) for accessing the info from this?

There are 2 things I'm considering.

1. To see the different options I need to scroll through the menu. I would need to modify or replace the LCD (and processor?) to display all the options at once.

2. Redirect the output to a carputer.

Thanks!

LuckiNite

So I found the pinout...

(1)emerald green 7- RAP Fuse Supply Voltage
(2)black w/ white stripe 8- Ground
(3)dark green w/ white stripe 9-VSS (Vehicle Speed Signal)
(4)light green w/ black stripe 10- Ambient Air temp Sensor **
(5)grey 11- Instrument Panel Lamp Fuse Supply Voltage
(6)purple w/ white stripe 12- LED Dimming Signal
(7)(empty) 13- *empty*
(8)orange 14-Battery Positive Voltage
(9)yellow 15- Trip computer/nav class 2 serial data link

**BEWARE! the sensor has a polarity. You'll know if its wired backwards 'cause the temp reading will be WAY off.

Looking up more info...

red_parchel

good information, interesting concept, a few questions come to mind,
1) where can i get a LCD like yours that shows MPG, trip, etc ... mine only shows temp/ direction, is there a model number?
2) how can we determine what kinda data is on these lines, and how can we read it? such as the "(9)yellow 15- Trip computer/nav class 2 serial data link" and the "(3)dark green w/ white stripe 9-VSS (Vehicle Speed Signal)" b/c i can see many different uses for such data IF it is serial or TTL.

if the data IS in some form of serial, i would more then likely want to create a second LCD powered by a micro-controller to show new things all at once and other information such as current speed, it could tie into my current micro-controller project

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americasfuture2

i have that display in my blazer. but it has hardly ever worked. and its been to cold for me chase the problem down. im thinking it may just be the entire display itself is fubar.

but i like that idea. having to glance up or having that green glow out of the corner of your eye is a distraction to driving at night.

i believe that in order for it to display the instant mpg, it needs the fuel level, amount of fuel being delivered by the injectors (pulse width and fuel pressure) being sent to the lil ohc display logic. it then calculates the fuel consumption and and tps reading to display as instant. and for the average it should just do an average formula to display it correctly.for the range it much calculate the average mpg to how many gallons are left in the tank. the avg speed looks as if will just calculate from the vss. that is 4000ppm.

__________________
Gathering parts----99% (I'll always want something else, its never 100%)
Using and programming in RR 3.14% (I need tons of help on this one!)
First Actual 98 Blazer LT Install
08 Aveo5 SV and 87 Fiero GT needing carputers

americasfuture2

here is some stuff that i know for these pinouts. it is all labled in red

(1)emerald green 7- RAP Fuse Supply Voltage
(2)black w/ white stripe 8- Ground
(3)dark green w/ white stripe 9-VSS (Vehicle Speed Signal) 4000 ppm
(4)light green w/ black stripe 10- Ambient Air temp Sensor **
(5)grey 11- Instrument Panel Lamp Fuse Supply Voltage circuit 1220
(6)purple w/ white stripe 12- LED Dimming Signal
(7)(empty) 13- *empty*
(8)orange 14-Battery Positive Voltage
(9)yellow 15- Trip computer/nav class 2 serial data link

__________________
Gathering parts----99% (I'll always want something else, its never 100%)
Using and programming in RR 3.14% (I need tons of help on this one!)
First Actual 98 Blazer LT Install
08 Aveo5 SV and 87 Fiero GT needing carputers

zr2

Hey guys,I am trying to wire up the overhead console into my 2003 s10 zr2 4x4 right now and your info was really helpfull.Thanks
The only thing I am having a problem with is locate VSS wire.Some web forums are saying that its the #3 drkgreen/white wire on CPU(engine computer)On my s10's CPU there is two plugs,each with 80 terminals,but there is no wires comming out of #3 terminals.Anybody have an idea where alse VSS 4000PPM wire is?I appreciate your help