LT1-LT4 Modifications 1993-97 Gen II Small Block V8

LT1 ECM Programming Problems

Thread Tools
 
Search this Thread
 
Old Aug 5, 2011 | 10:04 PM
  #1  
JL_94z28's Avatar
Thread Starter
On The Tree
iTrader: (6)
 
Joined: Nov 2010
Posts: 137
Likes: 3
Default LT1 ECM Programming Problems

Has anyone experienced issues with corrupt data taking out an OBD1 ECM? We managed to corrupt two ECM's after each successfully took 5 to 6 updates before crapping out. The battery had plenty of charge, no disruptions made during the flash, and TunerCATS showed a successful data flash in all cases. Was surprised to find that I was left a car that wouldn't start & fans that kick on immediately after you turn the ignition on. No rhyme or reason that we could find causing the issue. Has anyone experienced this in the past, or have any idea's where to look?? Is it possible to program the chip external from the ECM?? I had a TPI car, that I could flash the chip separate from the ECM...not sure if there is away to do that for an OBD1 computer from a 94 to 97 LT1 car. Can a corrupt ECM be salvaged?? Replacing ECM's is getting expensive. Nothing like getting twice on the dyno today..... Any help you can pass along would be appreciated. Thanks!!!
Reply
Old Aug 7, 2011 | 10:54 AM
  #2  
brettmc's Avatar
Banned
 
Joined: Sep 2009
Posts: 213
Likes: 1
From: st louis, mo area
Default

Isn't there an ecm recovery option in the software?
Reply
Old Aug 7, 2011 | 12:34 PM
  #3  
DAVE00's Avatar
TECH Fanatic
15 Year Member
iTrader: (10)
 
Joined: Jul 2007
Posts: 1,739
Likes: 2
From: Houston, TX
Default

Originally Posted by JL_94z28
Has anyone experienced issues with corrupt data taking out an OBD1 ECM? We managed to corrupt two ECM's after each successfully took 5 to 6 updates before crapping out. The battery had plenty of charge, no disruptions made during the flash, and TunerCATS showed a successful data flash in all cases. Was surprised to find that I was left a car that wouldn't start & fans that kick on immediately after you turn the ignition on. No rhyme or reason that we could find causing the issue. Has anyone experienced this in the past, or have any idea's where to look?? Is it possible to program the chip external from the ECM?? I had a TPI car, that I could flash the chip separate from the ECM...not sure if there is away to do that for an OBD1 computer from a 94 to 97 LT1 car. Can a corrupt ECM be salvaged?? Replacing ECM's is getting expensive. Nothing like getting twice on the dyno today..... Any help you can pass along would be appreciated. Thanks!!!
The problem lies with why do you have corrupt data? I have flashed my PCM over 100+ times tuning my car over the past 10+ years with ZERO flashing issues. Check all your grounds, make sure your battery (car) is good and laptop is on A/C power and all Virus programs and power mgmt programs are turned off. Where are you getting your .BIN files from? Mail order?
Reply
Old Aug 7, 2011 | 07:14 PM
  #4  
JL_94z28's Avatar
Thread Starter
On The Tree
iTrader: (6)
 
Joined: Nov 2010
Posts: 137
Likes: 3
Default

My .bin files are created by a friend who dyno tunes professionally. I completely trust those. I started tearing into the factory wire harness yesterday, focusing on ground feeds to the PCM. Is there a recovery file or a way to salvage a PCM? Is there a way to program the EEProm out of the car like in the older gen's?
Reply
Old Aug 8, 2011 | 02:42 AM
  #5  
lt4388stroker's Avatar
Launching!
iTrader: (14)
 
Joined: Jan 2009
Posts: 296
Likes: 0
From: Eden, NC
Default

I got spare pcm with a tune already on it, u can have it for 50 bucks shipped
Reply
Old Aug 8, 2011 | 06:33 AM
  #6  
DAVE00's Avatar
TECH Fanatic
15 Year Member
iTrader: (10)
 
Joined: Jul 2007
Posts: 1,739
Likes: 2
From: Houston, TX
Default

Originally Posted by JL_94z28
My .bin files are created by a friend who dyno tunes professionally. I completely trust those. I started tearing into the factory wire harness yesterday, focusing on ground feeds to the PCM. Is there a recovery file or a way to salvage a PCM? Is there a way to program the EEProm out of the car like in the older gen's?
I don't think so, unless you have a spare harness lying around and could create a bench testing/flashing environment. The PCM is not EProm based and you cannot remove the chip for burning. I would look into the BIN file to make sure it's not the problem as there has been reports in the past from other members about a corrupted .BIN taking out the PCM.
Reply
Old Aug 8, 2011 | 06:48 AM
  #7  
RamAir95TA's Avatar
TECH Senior Member
iTrader: (2)
 
Joined: May 2005
Posts: 9,467
Likes: 8
From: South Jersey
Default

Most mail-order tuners can repair fried PCMs. I know Ion can - happened to me once.
Reply
Old Aug 8, 2011 | 07:27 AM
  #8  
MEAN LT1's Avatar
TECH Fanatic
iTrader: (2)
 
Joined: Jan 2003
Posts: 1,143
Likes: 0
From: jacksonville,FL
Default

I agree with the above. Ion can resocket fried PCM's and there good as new.
Reply
LS1 Tech Stories

The Best V8 Stories One Small Block at Time

story-0

Amazing '71 Camaro Restomod Is Modern Muscle Car Under the Skin

 Verdad Gallardo
story-1

6 Common C5 Corvette Failures and What's Involved In Repairing Them

 Pouria Savadkouei
story-2

Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph

 Verdad Gallardo
story-3

Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked

 Pouria Savadkouei
story-4

Top 10 Most Powerful Chevy Trucks Ever Made!

 
story-5

Hennessey's New Supercharged Silverado ZR2 Has 700 HP

 Verdad Gallardo
story-6

Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes

 Verdad Gallardo
story-7

Awesome K5 Blazer Restomod Comes With C7 Corvette Power

 Verdad Gallardo
story-8

10 Camaros You Should Never Buy

 
story-9

10 LS Engine Myths That Refuse to Die

 Verdad Gallardo
Old Aug 8, 2011 | 07:48 AM
  #9  
DAVE00's Avatar
TECH Fanatic
15 Year Member
iTrader: (10)
 
Joined: Jul 2007
Posts: 1,739
Likes: 2
From: Houston, TX
Default

Originally Posted by MEAN LT1
I agree with the above. Ion can resocket fried PCM's and there good as new.
True - however unless the root cause of the "corruption" is found - corrupted .bins, grounding issues, etc... then I would not spend one dime getting a PCM resocketed as it will likely just happen again.
Reply
Old Aug 8, 2011 | 07:55 AM
  #10  
stevo9389's Avatar
TECH Enthusiast
 
Joined: Mar 2009
Posts: 680
Likes: 7
From: Clearwater
Default

you might need the "b" version of the $EE definition file? i only noticed 2 parts on the contstant table swapped around which was the giveaway for which version was needed. could be way off base but maybe that has been causing the problem.

i just recently made my own harness to run out of the car but for now it still requires me to connect it directly to the battery because i do not have a power supply yet to support it. if you are gettin less than 12.5v on all power connections to the PCM then you might be experiencing the intermittent tuning issues i have been having.
Reply
Old Aug 8, 2011 | 07:54 PM
  #11  
JL_94z28's Avatar
Thread Starter
On The Tree
iTrader: (6)
 
Joined: Nov 2010
Posts: 137
Likes: 3
Default

TunerCATS said they could salvage a smoked PCM for $25.00 - thought that seemed like a decent deal. My OBD1 PCM has 4 plugs with a total of 64 pins populated & the PCM wiring diagram I have shows 6 of those to be grounding pins. I assume those 6 pins should read 0 ohm resistance in a continuity test when grounded to the chassis correct? Thanks to everyone who has posted here! This is such a great site!!!
Reply
Old Dec 30, 2015 | 11:11 AM
  #12  
Snorkelface's Avatar
Launching!
 
Joined: Jul 2003
Posts: 258
Likes: 0
From: Rancho Cucamonga, CA
Default

Resurrecting this question since I'll be diagnosing my PCM soon. :/

Originally Posted by JL_94z28
TunerCATS said they could salvage a smoked PCM for $25.00 - thought that seemed like a decent deal. My OBD1 PCM has 4 plugs with a total of 64 pins populated & the PCM wiring diagram I have shows 6 of those to be grounding pins. I assume those 6 pins should read 0 ohm resistance in a continuity test when grounded to the chassis correct? Thanks to everyone who has posted here! This is such a great site!!!
Reply




All times are GMT -5. The time now is 09:28 AM.

story-0
Amazing '71 Camaro Restomod Is Modern Muscle Car Under the Skin

Slideshow: This heavily modified 1971 Camaro mixes classic muscle car styling with a fifth-generation Camaro interior and modern LS3 power.

By Verdad Gallardo | 2026-05-12 18:06:42


VIEW MORE
story-1
6 Common C5 Corvette Failures and What's Involved In Repairing Them

Slideshow: From wobbling harmonic balancers to failed EBCMs, these are the issues that define long-term C5 ownership and what repairs typically involve.

By Pouria Savadkouei | 2026-05-07 18:44:57


VIEW MORE
story-2
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph

Slideshow: A modern Camaro transformed into a retro icon, this limited-run "Bandit" build blends nostalgia with brute force in a way few revivals manage.

By Verdad Gallardo | 2026-04-21 13:57:02


VIEW MORE
story-3
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked

Slideshow: Cadillac didn't just crash the high-performance luxury vehicle party, it showed up loud, supercharged, and occasionally a little unhinged...

By Pouria Savadkouei | 2026-04-16 10:05:15


VIEW MORE
story-4
Top 10 Most Powerful Chevy Trucks Ever Made!

Slideshow: Top ten most powerful Chevy trucks ever made

By | 2026-03-25 09:22:26


VIEW MORE
story-5
Hennessey's New Supercharged Silverado ZR2 Has 700 HP

Slideshow: Hennessey has turned the Silverado ZR2 into a 700-hp off-road monster with supercharged V8 power and a limited production run.

By Verdad Gallardo | 2026-03-24 18:57:52


VIEW MORE
story-6
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes

Slideshow: A one-off sports car that looks like a vintage Italian exotic-but hides a C6 Corvette underneath-just sold for the price of a new mid-engine Corvette.

By Verdad Gallardo | 2026-03-23 18:53:41


VIEW MORE
story-7
Awesome K5 Blazer Restomod Comes With C7 Corvette Power

Slideshow: A heavily reworked 1972 K5 Blazer swaps its off-road roots for a low-slung street-focused build with modern V8 power.

By Verdad Gallardo | 2026-03-09 18:08:45


VIEW MORE
story-8
10 Camaros You Should Never Buy

Slideshow: There are thousands of used Camaros on the market but we think you should avoid these 10

By | 2026-02-17 17:09:30


VIEW MORE
story-9
10 LS Engine Myths That Refuse to Die

Slideshows: Which one of these myths do you believe?

By Verdad Gallardo | 2026-01-28 18:10:11


VIEW MORE