96 LT4 6spd
Instructor
Joined: Mar 2016
Posts: 184
Likes: 57
From: Bowling Green Ohio
2021 C5 of the Year Finalist - Unmodified
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It means a Code has set. You’ll have to pull the codes with the old paper clip trick or a scanner. If it’s a 96 you’ll have to research the method. Simple to do.
Le Mans Master
Joined: Jun 2009
Posts: 6,528
Likes: 752
From: South Dakota
On my '94, I had that "sys" show up a couple times before my battery completely died. After battery replacement it never showed up again.
It has been a few years ago, but I don't remember any codes set. Only the "sys".
I would try charging the battery up and see if you get still get the sys message. If it does not show up right after charging, then your battery was low and/or close to failure.
Good luck.
It has been a few years ago, but I don't remember any codes set. Only the "sys".
I would try charging the battery up and see if you get still get the sys message. If it does not show up right after charging, then your battery was low and/or close to failure.
Good luck.
Team Owner
Joined: Sep 2003
Posts: 25,373
Likes: 2,734
I believe with a '96 and "SYS" you actually do the diagnostics. If there's an ACTIVE CCM DTC other than PASS-KEY you can access it quite easily. I wouldn't assume battery. If you have "SYS" and "SECURITY" flashing there's for sure PASS-KEY issues I believe.
Do you have an FSM (Factory Service Manual) for the car?
Maybe the first check would be the AC fuse which provides power to the CCM to get to diagnostics. If that fuse is blown I believe you would have "SYS" .....
Do you have an FSM (Factory Service Manual) for the car?
Maybe the first check would be the AC fuse which provides power to the CCM to get to diagnostics. If that fuse is blown I believe you would have "SYS" .....
Thread Starter
Instructor
Joined: Aug 2017
Posts: 246
Likes: 6
Ok. So a battery and alternator test is in order. This "pass key", is that the ignition key with chip you are referring to?
If so, I did put a new set of keys inro service yesterday. They work smooth and perfectly. The Smith did not use the 22 year old key as a blank to cut the new one. He played kinda a numbers game to figure out the "code" that the originol key was cut to. Then by cutting cheap non chipped blanks until he got the numbers right, he cut keys EXACTLY like they were when they were new. Pretty slick!
If so, I did put a new set of keys inro service yesterday. They work smooth and perfectly. The Smith did not use the 22 year old key as a blank to cut the new one. He played kinda a numbers game to figure out the "code" that the originol key was cut to. Then by cutting cheap non chipped blanks until he got the numbers right, he cut keys EXACTLY like they were when they were new. Pretty slick!
Le Mans Master
Joined: Aug 2015
Posts: 6,090
Likes: 1,972
From: St. Charles MO
Ok. So a battery and alternator test is in order. This "pass key", is that the ignition key with chip you are referring to?
If so, I did put a new set of keys inro service yesterday. They work smooth and perfectly. The Smith did not use the 22 year old key as a blank to cut the new one. He played kinda a numbers game to figure out the "code" that the originol key was cut to. Then by cutting cheap non chipped blanks until he got the numbers right, he cut keys EXACTLY like they were when they were new. Pretty slick!
If so, I did put a new set of keys inro service yesterday. They work smooth and perfectly. The Smith did not use the 22 year old key as a blank to cut the new one. He played kinda a numbers game to figure out the "code" that the originol key was cut to. Then by cutting cheap non chipped blanks until he got the numbers right, he cut keys EXACTLY like they were when they were new. Pretty slick!
EDIT: Do you still have the original stereo head unit? If so, is it working? Apparently when replacing these the sys light comes on. There is some trick to running a resistor in the stock wiring harness to eliminate that issue.
Last edited by MatthewMiller; Jan 17, 2018 at 07:58 AM.
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Team Owner
Joined: Sep 2003
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When the locksmith was 'tinkering' I'd think he set the "SYS" light. Since the car cranks and runs he finally 'satisfied' the requirements but while 'tinkering' he set likely set it. He used brass work-key likely with no chip so with every rotation the CCM saw invalid (NO) resistance.Seems odd an experienced locksmith couldn't read the cuts of the key you had.
You say the head unit is now dead? Did it work before the key replacement? Did it work after the locksmith 'tinkered' with and made keys?
This should be an interesting read and you should be able to get the CCM codes using the DIC - an OBD2 code reader I doubt will do CCM codes. This reads quite closely to the FSM terminology and I believe after a couple reads a user should be able to do well.
http://tech.corvettecentral.com/2011...trouble-codes/
You've had the car how long? Never any crank/run or other issues?
You say the head unit is now dead? Did it work before the key replacement? Did it work after the locksmith 'tinkered' with and made keys?
This should be an interesting read and you should be able to get the CCM codes using the DIC - an OBD2 code reader I doubt will do CCM codes. This reads quite closely to the FSM terminology and I believe after a couple reads a user should be able to do well.
http://tech.corvettecentral.com/2011...trouble-codes/
You've had the car how long? Never any crank/run or other issues?
Last edited by WVZR-1; Jan 18, 2018 at 04:42 AM.
Thread Starter
Instructor
Joined: Aug 2017
Posts: 246
Likes: 6
Define C68.
Also the locksmith was very experienced. He recognized the originol key was worn beyond the ability to get the proper cut code from it. So he cut several "non chip" and therefore inexpensive keys until he got it right. Then he proceeded to cut my chip keys. All of which turn the ignition smoothly and the chip works with my vats. He did the same for my door keys. Perfect operation. Afterward he cut a spare set of junk keys to keep on file for in case i need some cut by a less experienced operator using just a duplicator cutter.
I am unconvinced it is key related. Otherwise, why would the key turn as well as start the car?
I will get obdII scan and battery and alt checked.
Stand by.
Also the locksmith was very experienced. He recognized the originol key was worn beyond the ability to get the proper cut code from it. So he cut several "non chip" and therefore inexpensive keys until he got it right. Then he proceeded to cut my chip keys. All of which turn the ignition smoothly and the chip works with my vats. He did the same for my door keys. Perfect operation. Afterward he cut a spare set of junk keys to keep on file for in case i need some cut by a less experienced operator using just a duplicator cutter.
I am unconvinced it is key related. Otherwise, why would the key turn as well as start the car?
I will get obdII scan and battery and alt checked.
Stand by.
Team Owner
Joined: Sep 2003
Posts: 25,373
Likes: 2,734
If the lock-smith is talented have him give you a key-code for both the ignition and door key so you can carry them on paper in your wallet for travel.
He should be able to take your cuts and give you 4 digit codes that you could carry in anywhere and get keys cut. Codes would be XXYX where X is numeric and Y a letter or maybe XYXX where X is still numeric and Y a letter.
An OBD2 CODE only scanner won't help you it needs to be a quality scanner that will do CCM/BCM. The link I gave you is sufficient for a DIY. Do you have the FSM? The FSM explains the same sequence.
Actually I believe the CCM code that set the "SYS" will likely go away with 100 key cycles. A scan would then only display a History code I'm quite sure.
You could also check Voltage using the jumper of the DLC 4 - 12.
Last edited by WVZR-1; Jan 18, 2018 at 08:30 PM.
Team Owner
Joined: Sep 2003
Posts: 25,373
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Had the lock-smith disconnected the battery until he got 'rotation' I doubt you'd have the "SYS" light.
I separated the CCM diagnostics from the FSM so if you follow these you should resolve codes, understand how to clear and likely move on. Could I be wrong? Of course but you need diagnostics.
96 Chevrolet Corvette SM(1199-1208)_1.pdf
I separated the CCM diagnostics from the FSM so if you follow these you should resolve codes, understand how to clear and likely move on. Could I be wrong? Of course but you need diagnostics.
96 Chevrolet Corvette SM(1199-1208)_1.pdf
Melting Slicks
Joined: Jul 1999
Posts: 3,214
Likes: 101
From: Decatur, Alabama
NORMALLY, Number one cause is cranking/starting your car with a LOW battery..it may still crank and start slowly but sill set SYS light. You can diagnose with jumper wires on the ALDL or better option, Tech1a with OBD2 adapter. Rare if you don't have access or friend with one.