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: 11,769
Likes: 175
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: 11,769
Likes: 175
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
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Top 10 Corvette Engines RANKED by Peak Torque (70+ Years of Muscle!)
Joe Kucinski
Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!
Verdad Gallardo
Top 10 Corvettes Coming to Mecum Indy 2026!
Brett Foote
Top 10 C9 Corvette MUST-HAVES to Fix These C8 Generation Flaws!
Michael S. Palmer
10 Revolutionary 'Corvette Firsts' Most People Don't Know
Joe Kucinski
5 Reasons to Upgrade to an LS6-Powered Corvette; 5 Reasons to Stay LT2
Michael S. Palmer
2027 Corvette vs The World: Every C8 vs Its Closest Competitor
Joe Kucinski
10 Most Common Corvette Problems of the Last 20 Years!
Joe Kucinski
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
