CorvetteForum - Chevrolet Corvette Forum Discussion

C3 Tech/Performance V8 Technical Info, Internal Engine, External Engine, Basic Tech and Maintenance for the C3 Corvette
Sponsored by:
Sponsored by:

Flashing codes - not grounded

Thread Tools
 
Search this Thread
 
Old Feb 2, 2006 | 10:50 AM
Share
  #1  
LONGFISH's Avatar
LONGFISH
Thread Starter
Advanced
 
Joined: Oct 2005
Posts: 76
Likes: 0
From: Tiffin Ohio
Default Flashing codes - not grounded
My '81 is flashing codes 21 & 55 when the key is on.
There is no jumper on the ALDL.
Is the ECM bad?
Anyone see this before?
Thanks
Reply
0
Old Feb 2, 2006 | 11:25 AM
Share
  #2  
cmac72's Avatar
cmac72
Instructor
10 Year Member
 
Joined: Sep 2004
Posts: 193
Likes: 0
Default
Did you go through the test proceedure with the terminals shorted out to see if you get the code 12? I have the instructions for the 81 GM computer testing at home. If you can't get an answer and want them, drop me a PM and I'll find some way to get them to you.
Reply
0
Old Feb 2, 2006 | 11:32 AM
Share
  #3  
LONGFISH's Avatar
LONGFISH
Thread Starter
Advanced
 
Joined: Oct 2005
Posts: 76
Likes: 0
From: Tiffin Ohio
Default
Yes I get code 12 first then 21 & 55.
It's like it is stuck in diognostic mode.
Reply
0
Old Feb 2, 2006 | 11:34 AM
Share
  #4  
cmac72's Avatar
cmac72
Instructor
10 Year Member
 
Joined: Sep 2004
Posts: 193
Likes: 0
Default
Never saw it happen - try (1) disconnecting the battery for 5 minutes to see if that re-sets is; (2) unplug the ECM (assuming you can get to it). Guess I can't be of much help, sorry.
Reply
0
Old Feb 3, 2006 | 08:14 AM
Share
  #5  
LONGFISH's Avatar
LONGFISH
Thread Starter
Advanced
 
Joined: Oct 2005
Posts: 76
Likes: 0
From: Tiffin Ohio
Default
ttt
Reply
0

Get notified of new replies

To Flashing codes - not grounded

Back to Subforum
C3 Tech/Performance
View Next Unread
My 76 dose not start.




Click for Advanced Search
Reply Closed Thread Share
Forum Jump
Trending Topics

All times are GMT -4. The time now is 02:04 PM.

story-0
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-1
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
story-2
Top 10 Corvette Engines RANKED by Peak Torque (70+ Years of Muscle!)

Slideshow: Ranking the top 10 Corvette engines by torque output.

By Joe Kucinski | 2026-05-05 11:58:09


VIEW MORE
story-3
Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!

Slideshow: A Corvette pace car nearly matching IndyCar speeds sounds exaggerated, until you look at the numbers.

By Verdad Gallardo | 2026-05-04 20:03:36


VIEW MORE
story-4
Top 10 Corvettes Coming to Mecum Indy 2026!

Among a rather large group of them.

By Brett Foote | 2026-05-04 13:56:44


VIEW MORE
story-5
Top 10 C9 Corvette MUST-HAVES to Fix These C8 Generation Flaws!

Slideshow: the top 10 things Corvette owners want in the C9 Corvette

By Michael S. Palmer | 2026-04-30 12:41:15


VIEW MORE
story-6
10 Revolutionary 'Corvette Firsts' Most People Don't Know

Slideshow: 10 Important Corvette 'firsts' that every fan should know.

By Joe Kucinski | 2026-04-29 17:02:16


VIEW MORE
story-7
5 Reasons to Upgrade to an LS6-Powered Corvette; 5 Reasons to Stay LT2

Slideshow: Should you buy a 2020-2026 Corvette or wait for 2027?

By Michael S. Palmer | 2026-04-22 10:08:58


VIEW MORE
story-8
2027 Corvette vs The World: Every C8 vs Its Closest Competitor

Slideshow: 2027 Corvette lineup vs the world.

By Joe Kucinski | 2026-04-24 16:12:42


VIEW MORE
story-9
10 Most Common Corvette Problems of the Last 20 Years!

Slideshow: 10 major Corvette problems from the last 20 years.

By Joe Kucinski | 2026-04-14 16:37:05


VIEW MORE