C4 Tech/Performance L98 Corvette and LT1 Corvette Technical Info, Internal Engine, External Engine

1992 lt1 ecm

Thread Tools
 
Search this Thread
 
Old Jan 24, 2017 | 08:26 PM
  #1  
tony58's Avatar
tony58
Thread Starter
Racer
 
Joined: May 2014
Posts: 468
Likes: 26
From: Middle Tennessee
Default 1992 lt1 ecm

Is it possible for a "92" LT1 to always start,always run flawlessly,get great gas mileage and have a bad EMC?The SES comes on every time I drive the car after reaching 180-190 temp.Code 26-Quad driver modual.I've contacted two local shops,both say it needs a new computer.
If it needs a new computer, I understand they are hard to come by? Any sources out there where one can be bought?
A large Chevy/Buick/GMC wont even work on anything older than a 2000.They no longer have the diagnostic tools to work on these.So anybody in the Nashville,Tennessee area that knows of a older Corvette friendly?
I'm trying to get the car fixed before Spring,so I can sell it.I'm sure Id take a beating trying to sell a car with a SES light on...
Reply
Old Jan 24, 2017 | 08:39 PM
  #2  
billschroeder5842's Avatar
billschroeder5842
Zen Vet Master Level VII
Supporting Gold
Veteran: Navy
10 Year Member
Liked
Loved
 
Joined: Mar 2016
Posts: 5,218
Likes: 1,174
From: Southlake, TX
Default

https://www.corvetteforum.com/forums...code-26-a.html

Here is a link from a CF discussion from a couple of years ago. Maybe a hidden gem for you
Reply
Old Jan 24, 2017 | 09:27 PM
  #3  
tony58's Avatar
tony58
Thread Starter
Racer
 
Joined: May 2014
Posts: 468
Likes: 26
From: Middle Tennessee
Default

Originally Posted by billschroeder5842
https://www.corvetteforum.com/forums...code-26-a.html

Here is a link from a CF discussion from a couple of years ago. Maybe a hidden gem for you
That is some good information.That seems to be close to the same problem I'm having.Difference is my car runs great,his was running crapy.The guy never stated what was the final fix was.Thanks again...
Reply
Old Jan 24, 2017 | 10:03 PM
  #4  
cardo0's Avatar
cardo0
Le Mans Master
20 Year Member
 
Joined: Oct 2002
Posts: 7,098
Likes: 378
From: Las Vegas - Just stop perpetuating myths please.
Default

That's part # 88999183 for 1992 corvette and 1993 V8 camaro's/firebirds. Rock Auto wants $212 for a reman ECM # 88999183. I found LT1 PCM's for $20 on Craigslist partouts. Try your local boneyard first.

Finding used bargain parts is most of the fun owning a Chevy.

Happy hunting.
Reply
Old Jan 24, 2017 | 10:18 PM
  #5  
MatthewMiller's Avatar
MatthewMiller
Le Mans Master
Liked
Loved
Community Favorite
Top Answer: 1
 
Joined: Aug 2015
Posts: 6,113
Likes: 1,994
From: St. Charles MO
Default

Originally Posted by tony58
That is some good information.That seems to be close to the same problem I'm having.Difference is my car runs great,his was running crapy.The guy never stated what was the final fix was.Thanks again...
Here's some more useful info. What this is saying is that the actual "driver module" is a current driver to drive some different components that require real current, rather than the milliamps that the ECM itself uses for its signals. Without this buffer, the little ECM signals would not successfully power these components. If the driver itself is bad, then I guess you're in for a new ECM. There are lots of places to get one, as cardo0 noted.

BUT...if one of those components driven by that module is bad instead, and maybe shorting the circuit, then the new ECM will be a waste of money and you won't solve your SES. That Saturn page I linked lists eight components that could cause this. I don't know if it will be the same eight in your C4, but I bet they are the same or close to the same. My bet is on one of those (you can obviously rule out the SES light being burned out!). But the point is, if something like your "Hot" light is burned out and causing the code, your car will still run great. The fact that it runs just fine makes me think it's not the module itself, but one of the devices that the module controls.
Reply
Old Jan 25, 2017 | 09:18 AM
  #6  
JimLentz's Avatar
JimLentz
Melting Slicks
Supporting Lifetime
10 Year Member
 
Joined: Jan 2014
Posts: 2,478
Likes: 254
From: Downers Grove Illinois
Default

I would put a scan tool on it while driving and make sure the ECM sees the correct engine temps when the problem occurs. These ECMs from the 92 and 93 Corvettes often have a cold solder problem that can cause all kinds of codes/issues. I sent mine off to a place in southern Illinois (SIA Electronics) where they fixed my ECM. It could be that one of the solenoids/relays doesn't operate until a certain temperature and when the ECM tries to operate it there is a short circuit that is detected and thrown as the code 26 you are seeing.
Reply
Old Jan 25, 2017 | 09:35 AM
  #7  
charliet615's Avatar
charliet615
Racer
 
Joined: May 2012
Posts: 392
Likes: 19
Default

Tony58, if you are in the Nashville area, there is one shop I would trust to work on the Corvette. It's the Car Care Center in Pegram, Tn just to the west of Bellevue. Contact Paul Jr @ 615-646-4685. I would let him work on my 93 any time. Charlie
Reply
Old Jan 25, 2017 | 04:28 PM
  #8  
tony58's Avatar
tony58
Thread Starter
Racer
 
Joined: May 2014
Posts: 468
Likes: 26
From: Middle Tennessee
Default

Originally Posted by charliet615
Tony58, if you are in the Nashville area, there is one shop I would trust to work on the Corvette. It's the Car Care Center in Pegram, Tn just to the west of Bellevue. Contact Paul Jr @ 615-646-4685. I would let him work on my 93 any time. Charlie
Thanks Charlie,I just called him,sounds like a very knowledgeable mechanic.He is the only one that said not to change out the computer before any testing.Wanting to sell the car,so got to do something.
I'm also trying to get a hold of Gordon Killebrew to see if he wants to fool with it?(He wrote and proof read our service manuals).I know him from cars shows and cruise in I attend.
Reply
Corvette Stories

The Best of Corvette for Corvette Enthusiasts

story-0

10 Ugly Corvettes That We Still Kinda Love

 Joe Kucinski
story-1

Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer

 Brett Foote
story-2

10 Things Every Corvette Owner Needs (2026 Edition)

 Michael S. Palmer
story-3

8 Most "Only Corvette Owners Understand" Quirks and Problems

 Pouria Savadkouei
story-4

10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years

 Joe Kucinski
story-5

How Much Horsepower Every Corvette Engine "LOST" in 1972

 Joe Kucinski
story-6

Top 10 DOs and DON'Ts for Protecting Your Convertible Top!

 Michael S. Palmer
story-7

Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!

 Joe Kucinski
story-8

150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter

 Joe Kucinski
story-9

8 Coolest Corvette Pace Cars (and Replicas) of All Time

 Verdad Gallardo
Old Jan 26, 2017 | 10:33 AM
  #9  
bjankuski's Avatar
bjankuski
Safety Car
20 Year Member
Photogenic
Liked
Top Answer: 1
 
Joined: Sep 2001
Posts: 4,157
Likes: 554
From: Glenbeulah Wi
Default

Originally Posted by tony58
Is it possible for a "92" LT1 to always start,always run flawlessly,get great gas mileage and have a bad EMC?The SES comes on every time I drive the car after reaching 180-190 temp.Code 26-Quad driver modual.I've contacted two local shops,both say it needs a new computer.
If it needs a new computer, I understand they are hard to come by? Any sources out there where one can be bought?
A large Chevy/Buick/GMC wont even work on anything older than a 2000.They no longer have the diagnostic tools to work on these.So anybody in the Nashville,Tennessee area that knows of a older Corvette friendly?
I'm trying to get the car fixed before Spring,so I can sell it.I'm sure Id take a beating trying to sell a car with a SES light on...
Code 26 does not mean computer failure, it is a failure of the evap circuit, it could be bad wiring or the solenoid. Follow the diagnostic chart in the service manual or find a shop that will do the same.
Reply
Old Jan 26, 2017 | 02:40 PM
  #10  
mixalive's Avatar
mixalive
Pro
15 Year Member
Liked
Loved
Community Favorite
 
Joined: Aug 2007
Posts: 668
Likes: 38
From: Austin TX
Default

That code will set on a 92 if the computer does not "see" the evap solenoid. Maybe disconnected, lost its ground or hot wire is broken. Probe the two wires of the evap solenoid with the solenoid connected with a DC volt meter. You should see a varying voltage up to 12 volts as you rev the engine past idle. The evap solenoid is on the passenger side of the intake manifold, connected with a hose to the throttle body, under the black plastic "Corvette" covers.

Last edited by mixalive; Jan 26, 2017 at 02:45 PM.
Reply
Old Jan 26, 2017 | 11:12 PM
  #11  
tony58's Avatar
tony58
Thread Starter
Racer
 
Joined: May 2014
Posts: 468
Likes: 26
From: Middle Tennessee
Default

Originally Posted by MatthewMiller
Here's some more useful info. What this is saying is that the actual "driver module" is a current driver to drive some different components that require real current, rather than the milliamps that the ECM itself uses for its signals. Without this buffer, the little ECM signals would not successfully power these components. If the driver itself is bad, then I guess you're in for a new ECM. There are lots of places to get one, as cardo0 noted.

BUT...if one of those components driven by that module is bad instead, and maybe shorting the circuit, then the new ECM will be a waste of money and you won't solve your SES. That Saturn page I linked lists eight components that could cause this. I don't know if it will be the same eight in your C4, but I bet they are the same or close to the same. My bet is on one of those (you can obviously rule out the SES light being burned out!). But the point is, if something like your "Hot" light is burned out and causing the code, your car will still run great. The fact that it runs just fine makes me think it's not the module itself, but one of the devices that the module controls.
I missed the Saturn page the first time.Found it the 2nd time.Thanks
Reply
Old Jan 26, 2017 | 11:22 PM
  #12  
tony58's Avatar
tony58
Thread Starter
Racer
 
Joined: May 2014
Posts: 468
Likes: 26
From: Middle Tennessee
Default

Thanks for all the replys. Wow, there are so many things that code 26 involves.Also found this old thread on Google.Might help someone as well as myself?
https://www.corvetteforum.com/forums...river-4-a.html
Reply
Old Jan 27, 2017 | 12:00 AM
  #13  
MatthewMiller's Avatar
MatthewMiller
Le Mans Master
Liked
Loved
Community Favorite
Top Answer: 1
 
Joined: Aug 2015
Posts: 6,113
Likes: 1,994
From: St. Charles MO
Default

Originally Posted by tony58
I missed the Saturn page the first time.Found it the 2nd time.Thanks
I hope it helps. And FWIW, one of the eight components in that article that are driven by the Saturn driver modules is the evap purge solenoid, as mentioned by mixalive. If the 92 C4 has anything in common, then that all fits together. That evap solenoid is probably a very good place to start checking.

But the bigger message is this: the factory service manual (FSM) will detail this code and provide a diagnostic flow chart to address it. You would also have a schematic to see everything that driver module powers. So if you have any inclination to diagnose and fix this yourself, it is worth laying your hands on the FSM.
Reply
Old Jan 28, 2017 | 10:09 PM
  #14  
tony58's Avatar
tony58
Thread Starter
Racer
 
Joined: May 2014
Posts: 468
Likes: 26
From: Middle Tennessee
Default

This might shed some light? I've got two C4's.On the 92 when I remove the gas cap even in cold weather, its like you turn on a propane tank.The 96 has little to no spewing out air.
Reply

Get notified of new replies

To 1992 lt1 ecm





All times are GMT -4. The time now is 07:49 AM.

story-0
10 Ugly Corvettes That We Still Kinda Love

Slideshow: 10 ugly Corvettes that we still kinda love.

By Joe Kucinski | 2026-06-03 10:34:17


VIEW MORE
story-1
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer

A lot of money has changed hands at the online auction house over the years.

By Brett Foote | 2026-06-03 10:21:50


VIEW MORE
story-2
10 Things Every Corvette Owner Needs (2026 Edition)

Slideshow: 10 great gifts Corvette enthusiasts actually want for Father's Day!

By Michael S. Palmer | 2026-06-03 15:43:40


VIEW MORE
story-3
8 Most "Only Corvette Owners Understand" Quirks and Problems

Slideshow: These are the quirks, annoyances, and oddly lovable problems that every Corvette owner eventually learns to live with.

By Pouria Savadkouei | 2026-05-28 09:31:39


VIEW MORE
story-4
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years

Slideshow: 10 reasons why the C6 Z06 is still a performance benchmark after 20 years.

By Joe Kucinski | 2026-05-27 17:20:09


VIEW MORE
story-5
How Much Horsepower Every Corvette Engine "LOST" in 1972

Slideshow: How much horsepower every Corvette engine lost in 1972.

By Joe Kucinski | 2026-05-27 16:54:53


VIEW MORE
story-6
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!

Slideshow: How to Protect A Convertible Top: 10 DOs & DON'Ts

By Michael S. Palmer | 2026-04-03 00:00:00


VIEW MORE
story-7
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!

Slideshow: The 10 most explosive Corvettes ever built based on power-to-weight ratio.

By Joe Kucinski | 2026-05-20 07:23:03


VIEW MORE
story-8
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter

Slideshow: From C1 to C8 we compare every Corvette generation by the numbers.

By Joe Kucinski | 2026-05-12 16:54:12


VIEW MORE
story-9
8 Coolest Corvette Pace Cars (and Replicas) of All Time

Slideshow: Some Corvette pace cars became collectible legends, while others perfectly captured the look and attitude of their era.

By Verdad Gallardo | 2026-05-11 09:50:51


VIEW MORE