What is scanning and tuning in the context of this FAQ?

Scanning - reading and storing real-time sensor readings and control variables in order to determine if/how ECM/PCM constants should be modified.

Tuning - modifying the constants in the lookup tables in the PCM in order to affect the operation of the drivetrain and related components like the cooling fans, VATS, etc.

Where to get more information:

Terminology
http://ls1lt1.com/forum/faq.php?faq=generaltech#faq_acronyms


LJ's PCM tutorial
http://para.noid.org/~lj/PCM%20Tutorial/PCMtutorial.htm
Best starting place for beginners.


How GM Electronic Fuel Injection Works
http://www.customefis.com/GMEFI.html


LS1LT1 PCM FAQ
http://ls1lt1.com/forum/faq.php?faq=generaltech#faq_pcmtuningpt1


LT1pcmtuning.com tips
http://www.lt1pcmtuning.com/tips/


LT1 Edit mailing list
http://www.lt1edit.com/mailman/listinfo/lt1edit

This is the best single source for advanced info, but searching the archives is a PITA. Best way is to download them into a mail program and search from there.


CamaroZ28 tuning forum
http://www.camaroz28.com/forums/forumdisplay.php?f=36

If you have a problem you are trying to diagnose, there are more people on this forum that have the know-how to help you than any other LTx tuning forum I've seen.


Impala SS tuning forum
http://www.impalassforum.com/vBulletin/forumdisplay.php?f=35

A few guys on this list have delved into stuff that other LT1 tuning forums don't have anything about, like DFCO and E85 tuning.


Some LSx tuning forums
http://www.hptuners.com/forum/forumdisplay.php?f=4
http://forum.efilive.com/forumdisplay.php?f=25

As more tables have been exposed in the LTx masks, the difference between LTx and LSx tuning has become smaller. And there's a lot more activity in the LSx forums

How Do I get Started?

You need three things to get started with scan/tune.

Software to scan with; software to tune with; and the hardware to use them.

Once you have those, read LJ's PCM tutorial linked above.



SCANNING

TTS Datamaster
http://www.ttspowersystems.com/DataMaster_downloads.html
is the most commonly used real-time scanning software for the 92-95 LT1.

Free trial is good for 20 scans, which may not seem like much at first, but it is quite a bit once you are actually using the data for analysis and tuning.

Unfortunately these guys are known for lousy customer service/support.

[update]
Tunercat is now a reseller for datamaster. I'd buy it from him, just in case he might be able to get you better customer service if you need it.
http://www.tunercat.com/DataMaster/dmaster.html
[/update]


Freescan
http://www.andywhittaker.com/ECU/FreeScan/tabid/70/Default.aspx

Haven't used it. Not supposed to be as good as datamaster, but it's free...



TUNING

TunerCat
http://tunercat.com/

Available for 92-95 (OBD1) cars.

The cheapest tuning software for these cars and thus used by most DIYers.

You need to purchase the tuner software and the appropriate mask for your car.

I can't begin to address how good the support for this software is. I'm regularly amazed at how I keep getting highly valuable improvements for free after a small investment several years ago.


LT1 Edit.

http://carputing.tripod.com/

Available for 94/95 (OBD1) and 96/97 (OBD2).

(No personal experience - somebody else want to comment here?)


Jet Dynamic Spectrum Tuner

http://www.jetchip.com/

For 96-97 (OBD2) PCMs.

This started out as TunerCat but was bought by Jet.



HARDWARE

For a 94--> car you need a laptop and an ALDL adapter/cable.

For a -->93 car you need that plus a chip burner.


There are numerous vendors for premade cables amd DIY cable kits. Just google "ALDL cable"

If you have a modern laptop with no serial port, get a cable that is made for USB rather than trying to use an RS232 cable with a USB adapter. Most USB adapters are crap and this is one of the applications that they have a lot of trouble with.

Oh, and the 15-pin D-Sub on the back of your laptop is not a serial port.


If you know your way around a soldering iron, there are several schematics on the web for making your own adapter.

Google for ALDL schematic and you should find several.

Here are a couple:
http://www.akmcables.com/aldlif.jpg
http://tinyurl.com/39sj8ky

Hypertech Power Programmer:

The Hypertech costs a lot more than Tunercat + cable, and does a lot less. But it is probably easier to use for the computer-fearing.

Somewhere on the web there is a list of the tables that hypertech changes. I'll put a link here when I find it.

Here it is:

http://www.z28.com/forum/showthread.php?t=6318
http://www.z28.com/forum/showthread.php?t=6319

Failed Flash:

On the 94--> cars you need to budget for the fact that, if you do this long enough, you're going to have a failed flash. When this happens your car will be unusable and you will either need to send the PCM for repair, or get a replacement. Repair is about $50, and used PCMs can be had for about $50 if you shop around (more like $75-100 if you are in a hurry.)

For about $75 Ion Soltan (madz28.com) will socket your PCM so you can then repair a failed flash yourself with a burner. If you're going to be doing much programming it's worth the price, especially since it seems to be one of those things where once you pay for the insurance, the calamity never happens to you again... (knock, knock)

Example BIN files:

There are a couple of LT1 BIN collections on the web:
http://www.bfranker.badz28.com/LT1Edit/LT1files.htm
http://www.moates.net/documentation.php?documentation_id=19


Perhaps we could start a database on this site?

ECM/PCM part numbers

Model    Year           GMpartNo       Engine
F,Y        1985         1226870       5.0L/5.7L
F,Y        1986-1989    1227165       5.0L/5.7L
F          1990-1992    1227730       5.0L/5.7L
Y          1990-1991    1227727       5.7L
Y          1992         16159278      5.7L LT1
F          1993         16159278      5.7L LT1
BF         1994-1995    16188051      5.7L LT1
Y          1994-1995    16181333      5.7L LT1/LT4
F,Y        1996         16214399      5.7L LT1
F          1997         16242921      5.7L LT1
F,Y        1997-1998    16238212      5.7L LS1
CK         1996-1997    16229684     4.3L,5.0L,5.7L,7.4L
                        16216568
                        16244210
CK         1998-1999    9359699       4.3L,5.0L,5.7L,7.4L
                        16250279
                        16258835

Taken from this site:
http://www.fuelinjection.com/portinj.html


A note on interchange - the computer hardware is generally the same between different car lines, but the software is different.

In particular, with the 94-95 PCMs you need to bench-flash with Y code before installing in the car. If you run the B/F code in the car you'll have trouble establishing communications with the PCM. This is probably because of communications conflicts between the CCM and the PCM, since the PCM is a master device in the F/B and a slave device in the Y.
[One person reports not having this problem. YMMV]
[Somebody else reported you can just pull the 2 fuses for the CCM then program the PCM. Haven't tested this myself]

There are hardware differences in the 94-95 Y PCMs vs. the F/B, but they are only related to the preliminary/experimental OBD2 functionality and not relevant for vehicle operation.


Common LT1 PCM interchanges

OBD1 (94-95) <--> OBD2 (96-97)

Putting a 94-95 PCM in a 96-97 car: use 94-95 knock sensors

Putting a 96-97 PCM in a 94-95 car: use 96-97 knock sensors, and disable the CPS DTC.



ECM (92-93) <--> PCM (94-97)

Changing over to a later PCM will require a new injector wiring harness, and you should probably use the later intake manifold. Not sure if that's all that's required.

$EE vs. $EEb code

If you have a 94-95 you will find that there are two Tunercat / LT1Edit masks, $EE and $EEb. The early 94s (seems to be about the first 5 or 6 months) used $EEb.

To tell which you have, open your bin file in $EE, and look at the constants table. If the cylinder volume is something ridiculously small (like 0) and the injector constant is something ridiculously large (like 793 lb/h) then you need to use $EEb.

You can upgrade to later code by flashing your computer with whatever code you want.

The important thing to take away - don't edit an $EE file using the $EEb mask or vice versa!


94 vs. 95 code

If you install 95 code in a 94 you need to disable DTC 83 and copy over the TCC apply/release rate tables from your old bin.

MT vs. AT code

They are different. Use code that matches your transmission.

Keep in mind that the cars with the newer dash can bring the codes up on the dash.

I found that out after I bought an expensive scanner.

Also, 94 & 95 are kinda oddballs, they have. They are OBDI cars but have OBDII connectors and computers.

Quote:

"scan" in this context isn't about getting codes, but rather real-time scanning needed for tuning.

I think "scan" info in the "retrieve trouble codes" sense goes in the general Tech FAQ rather than here.

I should probably make that clear up top...


Quote:

The 94/95 computer for all normal intents and purposes is OBD1. On the vette the 94/95 PCM implements a subset of OBD2 trouble codes, but the engine control is purely OBD1.

I followed the LT1 Edit link in the 1st post, but could not get the software link(s) to work. Any help is greatly appreciated.

Quote:

Not entirely sure I understand what you're asking, but click on
http://carputing.tripod.com/
then at the top on "94/95 LT1-Edit "
which takes you here
http://carputing.tripod.com/9495LT1Edit.htm
then click on "order form"
which takes you here
http://carputing.tripod.com/orderform.html

Tunercat is a lot cheaper and works on more than one car...

Here is a GREAT resource for newbs:

http://www.lt1pcmtuning.com/tips.php

I've never found LT1 PCM tuning information explained so well.

Lot's of good info here, an excellent contribution to our database.

Not sure if this is the place to ask this, so if it is not MOD please move to the appropriate place.

I need to know if there is a difference in the program code between a 94 6 speed car and an automatic? The PCM is the same # but I bought an extra that was from a 6 speed car. I figure if nothing else I could have it flashed with and automatic transmission image.

Am I making any sense?

Fixed it

What a great thread! Thank you!

I have two PCMs my software won't read at all. Both are for a '96 according to the stickers but I guess they are toast. Is Ion the only one you know of that can re socket them for that price?

Hello everyone. Has anyone loaded LT1 edit on to a WIN 7 64 bit OS? I have this right now and am experiencing problems beginning with doing a READ. The software locks up and I don't get more than a few percent (if at all) of the content read.

If you have any suggestions, I'd like to hear them, please.

Thanks,

Brian

yes, you're making perfect sense. If the new PCM matches your current one that ends in "333" (I believe) then with a Tech 2 and access to GM's stock codes you can have it flashed with your A$ (or automatic VIN) Then you may tune away from there.

Try running the XP emulation mode...

Right now I have WIN 7 Premium and to add XP emulator I'd need to upgrade to WIN 7 Professional for $199. Isn't there another way? I just dropped $$ on a new laptop AND more $$ for the LT1 Edit upgrades to work through USB Vs my old serial connection.

Thanks for the suggestion, but I am wondering if there's a less $$ solution?

Brian

*Update*

Under properties and compatibility mode, I tried out XP Svc pack2 and then three and tried a READ on my bench top setup.

I was not 100% successful but I was able to log the data. I got further with Svc Pack 2. So what does THAT mean????

The logs are available if anyone could make use of the info.

Attach file:

---

logcommOBD1FbodyUsingPCMREADXPSvcpack2.txt Size: 172.96 KB; Hits: 355

I think it's Sun Microsystems that offers a free XP emulator.