SYS code on odometer???
Thread Starter
Drifting
Joined: Sep 2003
Posts: 1,652
Likes: 2
From: 1990 383 Stroker Baltimore Maryland
SYS code on odometer???
I turned on my vette and about ever 10 seconds the letters SYS keep coming up where the average gas mileage total comes up? Does anyone know what that means??? Thanks 
Race Director
Joined: Sep 2004
Posts: 13,793
Likes: 0
From: St. Peters MO Sometimes you have to prove yourself by doing alot of killing or alot of dying...
I had the same thing happen to me when I first picked mine up. I asked the guy at Just Corvettes here in MO and he said not to worry about it unless it stays on. I changed my battery and it solved my problem!??!
Give that a try... hopefully it works for ya
Give that a try... hopefully it works for ya
Burning Brakes
Joined: Aug 2001
Posts: 1,238
Likes: 0
From: walled lake MI
Hey, Joe, sent ya an e-mail about retrieving CCM codes. In summary you have to short pins A and G (upper rightmost to lower leftmost) on the diagnostic connector and then key on. The LCD will show codes from the CCM, ECM, and EBCM in order. You can also erase the codes using the driver info center buttons (i.e. the trip/odo and gauge buttons).
I forgot to save a copy of the e-mail so could you post the contents here for everyone's benefit? Thanks.
I forgot to save a copy of the e-mail so could you post the contents here for everyone's benefit? Thanks.
Thread Starter
Drifting
Joined: Sep 2003
Posts: 1,652
Likes: 2
From: 1990 383 Stroker Baltimore Maryland
I check my ECM, I just keep getting the 12 code meaning everything is OK. It may have been because I had a low battery ( left the interior lights on 
)because when I charged it up it went away! You may have been right about the battery Kwik ta . Thanks guys problem solved!!!
)because when I charged it up it went away! You may have been right about the battery Kwik ta . Thanks guys problem solved!!!
Melting Slicks
Joined: May 2004
Posts: 2,286
Likes: 2
From: Stamping Ground KY
Low voltage on battery. Use a charger to bring the battery back up to 100%, alternators aren't meant to charge a battery from a low state. If it happens again, it's time for a new battery!
Melting Slicks
Joined: Jan 2002
Posts: 2,238
Likes: 4
From: Milan
Team Owner
Joined: Sep 2003
Posts: 25,295
Likes: 4
From: I'm the walkin dude I can see all of the world...
St. Jude Donor '03
Originally Posted by tempest
Hey, Joe, sent ya an e-mail about retrieving CCM codes. In summary you have to short pins A and G (upper rightmost to lower leftmost) on the diagnostic connector and then key on. The LCD will show codes from the CCM, ECM, and EBCM in order. You can also erase the codes using the driver info center buttons (i.e. the trip/odo and gauge buttons).
I forgot to save a copy of the e-mail so could you post the contents here for everyone's benefit? Thanks.
I forgot to save a copy of the e-mail so could you post the contents here for everyone's benefit? Thanks.
I would like to see that email!
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Burning Brakes
Joined: Aug 2001
Posts: 1,238
Likes: 0
From: walled lake MI
Just got a reply back from Joe.
Here's an excerpt from my original e-mail:
Here's an excerpt from my original e-mail:
I checked out my factory service manual and found that you can get codes
from your CCM pretty easy. Note this is for my 92 LT1 so your diagnostic
connector may be different. It should be under the driver side dash with a
cover on it.
First get a 2-3 inch length of wire to short out some leads. (I just used
speaker wire.) Turn ignition off. If you have the 12-pin OBD-II -style
connector (our cars are OBD-I), take your wire and ground pin G by shorting
it to pin A. If you are looking at the connector, the pinout is
FEDCBA
GHJKLM
so it would be the upper right to lower left. If you don't have the
12-pin, check the 'Net for the pinout.
Get a pencil and paper handy and turn ignition on. Pay attention as it
will immediately cycle through codes for, in order, the CCM (module 1), ECM
(module 4), ABS/ASR EBCM (module 9). The odo shows the module and the
speedo shows the codes. If you miss it the first time, just key off, wait
a few seconds and key back on. When I just did mine I had code 72 stored
in the CCM, even after I've disconnected the battery numerous times.
To clear codes in your CCM, wait until the codes cycle and the odo reads
"1.0". This means the CCM is waiting for input. Press the TRIP/ODO button
a few times until the numbers turn to 1.7. (You can go backwards by
pressing GAUGES) Press ENG/MET until the speedo shows "---", then key off.
Wait a few seconds and turn ignition back on to see if the codes have
cleared.
FYI you can clear codes for the other modules - just press TRIP/RESET or
FUEL RESET to change the module, Change the number after the decimal so you
get "X.7" and press ENG/MET as above. Key off, wait, and key on. Don't
forget to take your wire out after you key off.
from your CCM pretty easy. Note this is for my 92 LT1 so your diagnostic
connector may be different. It should be under the driver side dash with a
cover on it.
First get a 2-3 inch length of wire to short out some leads. (I just used
speaker wire.) Turn ignition off. If you have the 12-pin OBD-II -style
connector (our cars are OBD-I), take your wire and ground pin G by shorting
it to pin A. If you are looking at the connector, the pinout is
FEDCBA
GHJKLM
so it would be the upper right to lower left. If you don't have the
12-pin, check the 'Net for the pinout.
Get a pencil and paper handy and turn ignition on. Pay attention as it
will immediately cycle through codes for, in order, the CCM (module 1), ECM
(module 4), ABS/ASR EBCM (module 9). The odo shows the module and the
speedo shows the codes. If you miss it the first time, just key off, wait
a few seconds and key back on. When I just did mine I had code 72 stored
in the CCM, even after I've disconnected the battery numerous times.
To clear codes in your CCM, wait until the codes cycle and the odo reads
"1.0". This means the CCM is waiting for input. Press the TRIP/ODO button
a few times until the numbers turn to 1.7. (You can go backwards by
pressing GAUGES) Press ENG/MET until the speedo shows "---", then key off.
Wait a few seconds and turn ignition back on to see if the codes have
cleared.
FYI you can clear codes for the other modules - just press TRIP/RESET or
FUEL RESET to change the module, Change the number after the decimal so you
get "X.7" and press ENG/MET as above. Key off, wait, and key on. Don't
forget to take your wire out after you key off.
Melting Slicks
Joined: Jan 2002
Posts: 2,238
Likes: 4
From: Milan
I checked CCM codes on my '90
for CCM I had 3 codes:
H25
H40
H74
For ECM no codes.
I read that H is fo "History"
I read somewhere that the 25 code is a courtsy lamp realy short/open code
I don't know the others 2 codes (code 40 and code 74).
Is there some chart that explaine the CCM codes?
Thanks
-Beppe-
for CCM I had 3 codes:
H25
H40
H74
For ECM no codes.
I read that H is fo "History"
I read somewhere that the 25 code is a courtsy lamp realy short/open code
I don't know the others 2 codes (code 40 and code 74).
Is there some chart that explaine the CCM codes?
Thanks
-Beppe-
Thread Starter
Drifting
Joined: Sep 2003
Posts: 1,652
Likes: 2
From: 1990 383 Stroker Baltimore Maryland
Well I went out last night and the battery was still low so I bought a Sears Diehard Gold last night. I am not taking any chances. I think that "SYS" code is pretty handy if I had known what it was rather then ending up somewhere with a dead battery!
Race Director
Joined: Sep 2004
Posts: 13,793
Likes: 0
From: St. Peters MO Sometimes you have to prove yourself by doing alot of killing or alot of dying...
I thought the same when it happened to me. I bought my car and new the battery was weak because it would slow start the car... and the alternator would peak at 14.9 sometimes and drop to 13.5.
I was freakin about the sys thing!!! I thought I bought a crap car. I tried to reach the previous owner, called the dealer, and the guy at Just Corvettes wasn't much help. He said not to worry about it. A new battery cured all those problems.
I was freakin about the sys thing!!! I thought I bought a crap car. I tried to reach the previous owner, called the dealer, and the guy at Just Corvettes wasn't much help. He said not to worry about it. A new battery cured all those problems.
Burning Brakes
Joined: Oct 2002
Posts: 1,060
Likes: 0
From: Dixon Ca
Originally Posted by conv90
. Turned out to be the battery. Thanks to the great info from "Hooked On Vettes" 
