jimmyd1953

Just got my 1989 Corvette Friday. Now the car will not start. The security light keeps flashing. How do you reset security? Is there a way to turn it off? Could it be a bad chip in the key? I was only given one set of keys. Waited sever minute with key turned on. Locked and unlocked the door like the manual stated. Any ideas?

johnnymo63

Sometimes the contacts on the chip get dirty. Clean off both sides with alcohol or a pencil eraser.
I think the security light flashes just to remind you to activate the system. You may just have a bad battery connection. Good luck.

zr1fred

A flashing security lamp usually means its not reading the vats chip in the key, or either the information is not getting to the computer. As Johnnymo said make sure the key is clean and dry. Remember you must wait appox. 5 minutes before retry to reset the error.

Corvette40

In my 88 the security light flashes to remind me its not set. As soon as I lock the doors with the switch the light goes solid. I don't think the security light flashing means there's a problem or its active. I'll have to check the FSM though.

bangbgC6

My '89 is the same.

vetteoz

Anti theft door locks (break in ) is unrelated to the VATS ( start prevention)
Two independent systems

jimmyd1953

Thanks to all who replied. An update. This Corvette was sitting in a climate controlled garage for 7 years. Has only 43K miles. Great for an 89. The paint is original and fantastic for black. The interior is in good shape. What we found out:

Replaced the fuel filter, fuel pump, cleaned throttle body. Cleaned fuel injectors. Changed oil. Flushed radiator and replaced the radiator cap. Sometimes the car starts sometimes it does not. When it does not, we just prime it with carb cleaner and it starts right up. I drove it for 90 minutes today mostly highway. In the begining it was running rough. The more I drove the better it ran. It is an automatic. Going from second to third is sluggish. Once on the highway the car cruzed great at 75 and felt like it could do a lot more.

I am now thinking that there is a lot of carbon deposits that need to be blown out and might take a couple of tanks with good premium gasoline (no ethynol). My other thought is that it may require replacing the Engine Control Module. Everything else works fine on this car and it is a looker. I think it will be a nice little roadster once we get it road worthy again. My only concern is if this C4 becomes a money pit.

vetteoz

ECM's seldom fail, but the sensors and wiring to it do

1st thing to do would be to pull the engine fault codes and see if anything present
See
http://www.corvettephotographs.com/c4vettes/codes.htm

Corvette40

Here is what my 88 FSM states:

No Crank, ECM code 46 present -Test lock cylinder and harness, test decoder module.

Crank but no start, ECM code 46 present - ECM enable test

No crank, no ECM code 46 - Test starter enable relay

Crank but no start, no ECM code 46 - Refer to section 6E

Then it has 4-1/2 pages of test procedure. If you don't have an FSM, get a set. And vetteoz, you're right, the Forced Entry Alarm is separate from the Vehicle Anti Theft System.

Cliff Harris

The SECURITY light is operated by what GM calls the UTD (Universal Theft Deterrent) system. Most people call it TDS (Theft Deterrent System). That's the one that honks the horn if the door is opened while it's armed. You can arm the system with the door open but you must shut the door within 45 - 60 seconds or the horn will honk.

The SECURITY light will flash if the door is open, the ignition is off and the TDS is NOT armed.

The SECURITY light will be on solid if the door is open, the ignition is off and the TDS IS armed.

The SECURITY light will go off if you close the door or turn on the ignition.

johnnymo63

Good to see your on top of the fluid changes.

You need to get a can of "Sea-Foam" to put in your gas tank. That will clean out any contaminates in the fuel system really well.

jimmyd1953

Thank you very much for this information. I am picking some up now.

By the way, it runs like a champ on the highway when you get it up to 70 MPH.

JimmyD

bangbgC6

So under normal operation when the car is sitting locked the Security light should be Off?

What does constant flashing indicate when the vehicle is locked/parked?

Cliff Harris

It should be off.

It means that there is a problem in the TDS system somewhere. It could be a bad door jamb switch, problem with the wiring or a problem with the module itself. I have never heard of a problem with the module, but obviously it could happen. There is a general rule of thumb in the electronics biz: always suspect the mechanical parts first -- they are much more likely to fail than the electronics. That includes switches, relays and connectors.

The TDS wiring connections are shown on page 8A-133-0 in my '86 FSM. They are probably in the same section in other years. In my car the TDS module is taped to a wiring harness near the ECM. In earlier years it was located where the VATS module is now.