MikieG1971

I have noticed that on my digital screen where mph is displayed, it flashes "sys". Right to the left of the mph. What is that? There is no check engine light on.

STL94LT1

Low battery charge?

AJT84

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.

QCVette

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.

WVZR-1

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" .....

MikieG1971

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!

MatthewMiller

Right, the key could be physically cut perfectly, but if the resistor value in the "chip" within the key is not correct, then you are probably getting the light from that. I know next to nothing about these things - I thought the car wasn't supposed to start if the value isn't correct?

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.

Purple92

I believe that "SYS" an also be a communication error with another computer (e.g. the ABS computer).

The 1996 is a full OBDII system - so get a OBDII Code scanner and pull the code if possible.

MikieG1971

The key starts the car. The head unit is dead. Hmmm.

MatthewMiller

Does it's death coincide with the sys indicator's appearance?

WVZR-1

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?

MikieG1971

Not sure. Just got the car and it was already dead.

JimLentz

Does it have the C68 climate control?

MikieG1971

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.

JimLentz

C68 is the automatic temperature control.

WVZR-1

I didn't say it was 'key related' NOW - I said I believe he created the "SYS" while tinkering. Rotating the blank 'no resistance' work-key until he arrived an a cut that rotates it. After he determined the cuts he then cut you a working key with the correct resistance and gave you crank/run.

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.

WVZR-1

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

corvette95

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.

MikieG1971

Here are the codes i found,
P0300
P0100
P0171
P0507
P1661
What do you folks make of this?
And, yes. My car does have the C68 control.

MikieG1971

Anybody? Beuller? Beuller?