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Flashing SYS Light

OldCorvetteFan

Well-known member
Joined
Jul 3, 2005
Messages
117
Location
Northwest Illinois
Corvette
Black 95 6 spd Coupe (Sold); 2011 GS
'95 coupe
six speed
LT1
stock

Here are the relevant details ...

Thursday evening, when I started the Vette to move it back into the garage, I noticed that it turned over just a bit reluctantly. Not enough to keep it from starting, but just on the edge of my consciousness.

Yesterday morning, getting ready to pull it out of the garage, it did the same thing (this time I was paying attention to it). I pulled it out, shut it down, then restarted it, and the starter motor sounded like it normally does.

Yesterday afternoon, the wife and I decided to take a Friday afternoon drive. It was back to the "slow" start - but started. When we stopped to get a drink, I stayed in the car with it running. At that time, I noticed that SYS was flashing.

We then returned home (no sense tempting fate). I then consulted my trusty FSM, which states to pull the codes.

I also took a look at the Delco battery (I'm pretty sure it isn't the original), and it has a nice green dot showing.

At that point, I decided to fire it up again. Battery voltage prior to starting (after the fuel pump primed & stopped) was 13.7 V. During starting, it dropped to about 10 (hard to tell). The car fired up with no starter hesitation, and battery read 13.7 V. I turned on the AC, and battery voltage crept up to about 14.

However, this time there was no SYS light flashing.

I pulled the following codes this morning ...

H31, H33, H35, & H37 - all from Module 1

There are no current codes.

How long before these codes go away? 100 starts?

I also took the car to Autozone, where they tested the battery. That test came back indeterminant. At the end of the test, the machine said to recharge the battery and repeat the test. That would seem to point toward a battery that is getting ready to fail.

Any thoughts/suggestions?

Thanks,
Steven
 

KOPBET

Well-known member
Joined
Jan 31, 2003
Messages
1,355
Location
Tulsey Town
Corvette
'73 Silver LS4 4 speed
Bad battery or one with a considerable state of undercharge. If you don't know how old the battery is replace it. The summer heat may kill it completely when you least expect it.
 

72Slydog

Active member
Joined
May 30, 2002
Messages
38
Location
Charlotte, NC USA
Corvette
96 LT1 Competion Yellow
I had the same problem with my 96 LT1. After replacing the third battery I ended up replacing the positive battery cable and the problem was fixed and never returned.
 

OldCorvetteFan

Well-known member
Joined
Jul 3, 2005
Messages
117
Location
Northwest Illinois
Corvette
Black 95 6 spd Coupe (Sold); 2011 GS
Afternoon update ...

Had to move car out of the garage to finish up my insulation project. It started slowly. When I moved it back into the garage, it started slowly.

I concluded that I needed to remove the battery for further testing (although it was looking more and more likely that the battery was the culprit).

When I attempted to remove the postive cable, the battery post came with it - and not a lot of force to do it, either!

So, I have concluded that the battery is the likely problem, and went to Autozone to get a replacement (along with replacement terminal bolts). When the temp drops a bit more, I'll get back out there and see if I can get it all buttoned up.

Steven
 

OldCorvetteFan

Well-known member
Joined
Jul 3, 2005
Messages
117
Location
Northwest Illinois
Corvette
Black 95 6 spd Coupe (Sold); 2011 GS
Evening update ...

New battery installed.

Lessons learned ...

1. I bought new terminal bolts to replace the one for the positive side (very corroded). Did you know that the positive termonal bolt is LONGER than the negative terminal bolt? I didn't, and spent a good bit of time trying to get the short negative bolt into the terminal on the battery. Just on a whim, I checked the other one to see if it would screw into the battery, and then I thought maybe they are different - and they are!!! Once I made the swap, the positive cable hooked right up.

2. Once you have the right bolt for the positive cable, it is much easier to get it started if the battery is only partially set in the battery box. The first time I tried this, I had installed the hold down bracket, and I couldn't get my fat fingers into the small space provided near the positive terminal.

3. Clay bar works really well on the inner fender, and a couple of other places around that bettery. I'm not much of the detailer kind of Corvette owner, but I spent some time cleaning up a little while I had it apart. The clay and detail spray left a nice factory looking finish without a lot of work on my part (very important to me!).

Once I got everything buttoned up, I climbed in and she fired right up. No SYS flashing its nastiness. I set the clock, enjoyed the AC for a few minutes, shut it down, and restarted it. No problems.

I'm declaring this one solved - unless someone else has any suggestions about those history codes I found this morning.

Steven
 

Robertwav1

Well-known member
Joined
Jan 7, 2003
Messages
821
Location
Ocala, Florida
Corvette
1993 Blue
Just to add that "SYS" flashing on my car was a low battery. The green indicator doesn't work from what I had experience with. Also experienced what you did, the slow cranking. I wouldn't worry too much about the codes you got then, clear them and start new with the new battery. False codes can be triggered by low battery voltage. All kinds of crazy things can happen when the electronics are fooled by low voltage.
 

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