1991 SYS Message
Thread Starter
5th Gear
Joined: Feb 2013
Posts: 5
Likes: 0
From: Waxhaw NC
1991 SYS Message
My SYS message keeps flashing so I put in a rebuilt ECM and now the car hardly runs - running very very rough to the point I headed for home as soon as possibel thinking I may not make it. Have others had this issue? Thanks.
Race Director
Joined: Oct 2005
Posts: 11,771
Likes: 177
From: Rolla Missouri
2021 C4 of the Year - Unmodified Finalist
St. Jude Donor '10 thru '25
What other reason (besides a flashing SYS message) led you to replace the ECM?
Race Director
Joined: Oct 2005
Posts: 11,771
Likes: 177
From: Rolla Missouri
2021 C4 of the Year - Unmodified Finalist
St. Jude Donor '10 thru '25
Ok, that was your biggest mistake.
That may or may not be the fix for your car.
You need to follow the proper diagnostic procedures.
I am not a mechanic, so I will leave that to some of the experts here.
Don't just through parts at these things *****-nilly.
You'll just empty out your wallet.
Other than the flashing SYS, was the car running fine?
If your only issue was a flashing "SYS" every few seconds, then put your factory EMC back in.
How old is your battery? Are you 100% sure it is good and fully charged?
Have you recently added an aftermarket audio system?
A flashing "SYS" does indicate an electrical system issue.
But there are many things that might cause it, including a discharged battery or aftermarket audio system.
That may or may not be the fix for your car.
You need to follow the proper diagnostic procedures.
I am not a mechanic, so I will leave that to some of the experts here.
Don't just through parts at these things *****-nilly.
You'll just empty out your wallet.
Other than the flashing SYS, was the car running fine?
If your only issue was a flashing "SYS" every few seconds, then put your factory EMC back in.
How old is your battery? Are you 100% sure it is good and fully charged?
Have you recently added an aftermarket audio system?
A flashing "SYS" does indicate an electrical system issue.
But there are many things that might cause it, including a discharged battery or aftermarket audio system.
Thread Starter
5th Gear
Joined: Feb 2013
Posts: 5
Likes: 0
From: Waxhaw NC
Ok, that was your biggest mistake.
That may or may not be the fix for your car.
You need to follow the proper diagnostic procedures.
I am not a mechanic, so I will leave that to some of the experts here.
Don't just through parts at these things *****-nilly.
You'll just empty out your wallet.
Other than the flashing SYS, was the car running fine?
If your only issue was a flashing "SYS" every few seconds, then put your factory EMC back in.
How old is your battery? Are you 100% sure it is good and fully charged?
Have you recently added an aftermarket audio system?
A flashing "SYS" does indicate an electrical system issue.
But there are many things that might cause it, including a discharged battery or aftermarket audio system.
That may or may not be the fix for your car.
You need to follow the proper diagnostic procedures.
I am not a mechanic, so I will leave that to some of the experts here.
Don't just through parts at these things *****-nilly.
You'll just empty out your wallet.
Other than the flashing SYS, was the car running fine?
If your only issue was a flashing "SYS" every few seconds, then put your factory EMC back in.
How old is your battery? Are you 100% sure it is good and fully charged?
Have you recently added an aftermarket audio system?
A flashing "SYS" does indicate an electrical system issue.
But there are many things that might cause it, including a discharged battery or aftermarket audio system.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Burning Brakes
Joined: Mar 2010
Posts: 1,094
Likes: 68
From: Providence RI
did you take the mem-cal off of your old ecm and put it in the new one?
Whats the battery voltage? Is you alternator charging?
Did you mess with any wires under the passenger side kick panel? Reason why I ask is because when I installed an ipod adapter I hooked up two connectors wrong because they are the same pigtails under the passenger side dash.
What was the stored code? How are your fuses for the radio and cluster?
Mike
Whats the battery voltage? Is you alternator charging?
Did you mess with any wires under the passenger side kick panel? Reason why I ask is because when I installed an ipod adapter I hooked up two connectors wrong because they are the same pigtails under the passenger side dash.
What was the stored code? How are your fuses for the radio and cluster?
Mike
Thread Starter
5th Gear
Joined: Feb 2013
Posts: 5
Likes: 0
From: Waxhaw NC
did you take the mem-cal off of your old ecm and put it in the new one?
Whats the battery voltage? Is you alternator charging?
Did you mess with any wires under the passenger side kick panel? Reason why I ask is because when I installed an ipod adapter I hooked up two connectors wrong because they are the same pigtails under the passenger side dash.
What was the stored code? How are your fuses for the radio and cluster?
Mike
Whats the battery voltage? Is you alternator charging?
Did you mess with any wires under the passenger side kick panel? Reason why I ask is because when I installed an ipod adapter I hooked up two connectors wrong because they are the same pigtails under the passenger side dash.
What was the stored code? How are your fuses for the radio and cluster?
Mike
