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

1993 code 51 problem

Thread Tools
 
Search this Thread
 
Old Jun 24, 2009 | 07:46 AM
  #1  
txvette170's Avatar
txvette170
Thread Starter
Cruising
 
Joined: Jun 2009
Posts: 10
Likes: 0
From: san antonio tx
Default 1993 code 51 problem

I have a 1993 LT1,have replaced ecm and prom,it keeps throwing a code 51,car runs fine,any body have any ideas. thanks
Reply
Old Jun 24, 2009 | 02:13 PM
  #2  
ChrisWhewell's Avatar
ChrisWhewell
Pro
 
Joined: Jan 2009
Posts: 686
Likes: 4
From: Austin Texas
Default

Originally Posted by txvette170
I have a 1993 LT1,have replaced ecm and prom,it keeps throwing a code 51,car runs fine,any body have any ideas. thanks
Thats a tough one. Maybe a bad resistor in a relay is allowing voltage to creep back in where it doesn't belong ? Or a ground fault in the fan relay circuit ? I don't know, just tossing ideas.

Do you live near Area 51 ?
Reply
Old Jun 24, 2009 | 02:35 PM
  #3  
txvette170's Avatar
txvette170
Thread Starter
Cruising
 
Joined: Jun 2009
Posts: 10
Likes: 0
From: san antonio tx
Default

nope texas
Reply
Old Jun 24, 2009 | 02:41 PM
  #4  
ChrisWhewell's Avatar
ChrisWhewell
Pro
 
Joined: Jan 2009
Posts: 686
Likes: 4
From: Austin Texas
Default

Originally Posted by txvette170
nope texas
Me too, Austin. Mine's a 93 also.
Reply
Old Jun 24, 2009 | 02:45 PM
  #5  
whalepirot's Avatar
whalepirot
Melting Slicks
15 Year Member
 
Joined: Jan 2008
Posts: 2,054
Likes: 120
From: AZ
Default

this may help. http://chevythunder.com/199295_lt1_trouble_codes.htm

Why did you change the ECM and PROM originally? Seems you got some bad electronics there, throwing PROM faults.
Reply
Old Jun 24, 2009 | 03:02 PM
  #6  
txvette170's Avatar
txvette170
Thread Starter
Cruising
 
Joined: Jun 2009
Posts: 10
Likes: 0
From: san antonio tx
Default

scan tool gave code 51 prom error,read my manual it said to replace prom if still getting code 51 replace ecm
Reply
Old Jun 24, 2009 | 03:04 PM
  #7  
Hooked on Vettes's Avatar
Hooked on Vettes
Melting Slicks
15 Year Member
 
Joined: Aug 1999
Posts: 2,240
Likes: 42
From: Baltimore, MD USA
Default

Are you sure it's an ECM error code and not a CCM error code?

SYS flashing in the LCD would indicated a CCM 51 which is a problem reading the key pellet. Usually a dirty/worn key pellet or bad ignition key cylinder.

Service Engine Soon lamp on with a DTC 51 would indicated a ECM eprom or ECM problem.

What method are you using to pull codes. If via the CCM by shorting pin A to Pin G, Module 1 are codes for the CCM and Module 4 are codes for the ECM.

Last edited by Hooked on Vettes; Jun 24, 2009 at 03:11 PM.
Reply
Old Jun 24, 2009 | 03:35 PM
  #8  
txvette170's Avatar
txvette170
Thread Starter
Cruising
 
Joined: Jun 2009
Posts: 10
Likes: 0
From: san antonio tx
Default

dtc 51,using a scan tool
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 Jun 24, 2009 | 03:45 PM
  #9  
Hooked on Vettes's Avatar
Hooked on Vettes
Melting Slicks
15 Year Member
 
Joined: Aug 1999
Posts: 2,240
Likes: 42
From: Baltimore, MD USA
Default

What's the history of the car?
Did some one burn a new eprom for you?
You say the car runs fine even with DTC 51?
Reply
Old Jun 24, 2009 | 04:13 PM
  #10  
txvette170's Avatar
txvette170
Thread Starter
Cruising
 
Joined: Jun 2009
Posts: 10
Likes: 0
From: san antonio tx
Default

I bought a new prom from GM ,runs good ,just gives service eng. soon light, i check the codes and it's a dtc 51,turn it off and restart light is out,you can drive for a mile or 20 miles all sudden the ser. eng. lights up no pattern to it .
Reply

Get notified of new replies

To 1993 code 51 problem





All times are GMT -4. The time now is 05:01 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