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black87buick
06-21-2013, 02:02 AM
Looking for information on updating my gauges. My speedo is dead as well as the in dash tach (it has old VDO gauges in it)
I heard a rumor and seen a poor video that modern GM OEM gauges can be used in a GN, but no information was provided or found yet..:popcorn:.

Or can some one point me to some technical information for these cars to parse the ECM data stream that tools like the scanmaster use to display Speed, RPM etc.

Thanks,
-Chad

Shawn N
06-21-2013, 03:38 AM
Never heard of newer GM gauges being used and it does not seem it would work or fit. If your speedo is not working the upper cable is the usual suspect. Casper's Electronics can repair the led tach for $120 if I remember correctly. GNX repro clusters can still be found here and there but they usually close to a $1000 for one w/o the plug and play harness. It would increase the selling value of your TR though if you ever decide on selling the car.

black87buick
06-21-2013, 12:12 PM
Never heard of newer GM gauges being used and it does not seem it would work or fit. If your speedo is not working the upper cable is the usual suspect. Casper's Electronics can repair the led tach for $120 if I remember correctly. GNX repro clusters can still be found here and there but they usually close to a $1000 for one w/o the plug and play harness. It would increase the selling value of your TR though if you ever decide on selling the car.

I just realized I put this in the wrong topic. Should probably be moved by the moderator.

$1000 Whoa.

My car has the GNX style gauge cluster layout as I told with all VDO guages. I have removed the cluster. The Speedo when turning the cable drive by hand locks up...it is toast without a doubt. I wish it were the cable but oh well. The tach is fried, probably because of the previous owner's crappy wiring job...I posted the fuel pump mess on this site as an example of his workmanship.

There has to be a way to demux the ECM data stream to drive new GM OEM gauges. Doing an LED tach is simple, I even have the chips to build one if needed, but that seems hardly worth it right now because of the dash layout.

Right now the idea to update to new OEM GM gauges is a goal. All the remaining gauges (Oil press, Water Temp etc) work but they are all faded and ugly. I might as well buy a complete replacement set (most auto parts places have aftermarket gauges in varying shapes and sizes in stock) or do something cool and update them like a did my Riviera hence this discussion. :dunno:

black87buick
06-21-2013, 12:54 PM
Awesome Link

http://www.ws6transam.org/ALDL.html

http://techedge.com.au/vehicle/aldl160/aldl_sw.htm

http://wbo2.com.au/~techedge.com.au/vehicle/aldl160/aldl_hw.htm

for US vehicles
http://wbo2.com.au/~techedge.com.au/vehicle/aldl8192/8192hw.htm

SW links that work
http://www.alanmcnicol.dsl.pipex.com/M100_ALDL.html

http://sourceforge.net/projects/jaldl/files/latest/download

http://sourceforge.net/projects/freescan/?source=dlp

Shawn N
06-21-2013, 01:00 PM
Why not go with a Stewart Warner set of gauges that were in the GNX? They are discontinued but can be still found on eBay in complete sets except for the boost gauge which is kinda scarce nowdays. It only went to 15psi though, not much use for it anyway.

Keller
06-21-2013, 01:39 PM
Or can some one point me to some technical information for these cars to parse the ECM data stream that tools like the scanmaster use to display Speed, RPM etc.
Probably don't want to use the ALDL data stream, because it updates every 1.44 seconds.

There is a connector inside the ECM that provides a much faster rate. Not familiar with the pinout details. But that is what the PowerLogger (and DirectScan before it) used.

What about a GPS driven speedometer?

There is a tach connector on the engine harness that provides a 5V squarewave if I recall correctly.

kenmosher
06-21-2013, 02:02 PM
BTW, that circuit is good for a hack but can be pretty noisy, especially on 8192 baud later GM cars. I don't think I'd trust it for gauges. If you had a later P4 ECM (like the F-Bodies) then the 8192 baud and bigger data frames could probably do a decent job.

On our older C3 ECMs and 160 baud, it's probably a non-starter.

... AND ... most of the GM gauge clusters that are newer, use the GM 1 wire CAN interface or the older GM LAN2 Serial Stream (at 8192 baud).

black87buick
06-21-2013, 02:35 PM
BTW, that circuit is good for a hack but can be pretty noisy, especially on 8192 baud later GM cars. I don't think I'd trust it for gauges. If you had a later P4 ECM (like the F-Bodies) then the 8192 baud and bigger data frames could probably do a decent job.

On our older C3 ECMs and 160 baud, it's probably a non-starter.

... AND ... most of the GM gauge clusters that are newer, use the GM 1 wire CAN interface or the older GM LAN2 Serial Stream (at 8192 baud).

Thanks for the information...I am combing through all the information on the web I can find now.

Taking a step back, that large square area would be prime for a simple NTSC or VGA screen that could be made to look like gauges with an analog "feel" many 2010 and newer cars have....

I am just looking for elegant but unique solutions/ideas that enhance the originality/cool factor of the GN. Buying a suite of new gauges (VDO, Warner etc) is definitely an option.

It seems that the 8192 baud rate serial interface can be ported to HMI/Gauges and placed on a screen in the original cluster area. I might abandon the GM OEM gauge idea...dunno...all of this takes time and more research. I'll need to estimate time and complexity of these options 1.) New OEM GM style gauges (build an interface from the ALDL) or straight to the NTSC/VGA screen with the "feel" of analog gauges. I assume that the 8192 signal can be normalized and filtered.

kenmosher
06-21-2013, 03:48 PM
You won't get enough data fast enough for any kind of computerized realtime gauge display using the C3 ALDL. Trust me ...

You don't have an 8192 option using stock components. You'd have to figure a way to hack in a P4 with custom ROM, custom EPROM with calibration, the internal cam sensor (24x I think) of the 3800 and on and on. It *CAN* be done and bits and pieces of it HAVE been done.

Downside, big $$$ and hundreds of hours of time.

Simplest option is just replace the gauges with off-the-shelf stuff and call it good.

black87buick
06-22-2013, 12:55 PM
Thanks Ken. You are right, getting some after market gauges makes sense.

I did a bit more research, My car has a reman ECM and looking at the components/chips based upon this link:
http://www.diy-efi.org/gmecm/archive/html_gm_archive_num_12/msg06399.html

Looks like my reman ECM may have the higher timing chip to support 8192 baud, but who knows. :dunno:

kenmosher
06-22-2013, 01:38 PM
No it doesn't. The timing of the data stream is dependent on the C3 architecture. The only way to get the higher baud rate is to swap in a P4 and basically rewire a large portion of the engine electronics.

daveismissing
08-16-2013, 06:23 PM
I would be far more time/cost cost effective to install a power logger
and decode that data stream for a display.