tweetyvette

So I was at the grocery store Saturday, and my car wouldn't crank. Had to be towed home. Its a 1991 with 106000 miles, manual 6 speed tranny. It was acting funny when I pulled up like it needed the fuel injectors cleaned, yanno the rattling sound. When I came out stuck the key in, lights came on the dash but would not crank, had it towed home and a friend checked it out. No fire to starter so he bypassed the wiring and it would turn over but would not crank, found no fire to the fuel delivery system. It also has had a BBK throttle body installed but I don't see that as the problem. I kinda suspected security system so I got out my service manual, and did what they said to check the security system. Sure enough the horn blew so I know the system is working. I think its the key or the ignition switch. When I take the key out the security light flashes like its supposed to, with the key in and turned to on or even twisting like you are going to crank it the security light is on solid and somehow that doesn't sound right. When it wouldn't crank at the grocery store hubby brought another battery and installed it, wouldn't turn over with it either is how we know its not the battery. I have had this car for eight years with never any type of problems. I checked all the fuses with a test light and they are all good. I only have one ignition key, do you think if I bought another and had it programmed that would be the first place to start? Any suggestions are welcome, since having it towed to a mechanic is gonna be a pain in the behind! I love my car and want it back running!

l98tpi

Get a new key or try another one if you have two. It is your vats security system. I just had mine deleted, bypassed. But I don't know how to di it myself. I'm sure someone here can tell you.

1993C4LT1

Try cleaning the pellet on the key.

tweetyvette

Tried cleaning the pellet, didn't help, thanks for mentioning. Only have one key! I am looking at Ecklers and they have a security override system pretty reasonable but you have to take the key to a dealer to find the resistance, so if I'm there might as well get a new key

TA

If you have a multimeter you can do it yourself.

Netfly

Probably its the key pellet, but try this: put your door key in the door and lock and unlock it with the key. It may reset the system.

tweetyvette

tried the door key locked and unlocked couple times, still didn't turn over. Thanks though!

Hooked on Vettes

You can run the CCM (Central Control Module) diagnostic and it will tell you if there is a problem reading the key pellet resistance.

The Security light blnking is probably because you have a
door open.

Normal operation is when you insert the ignition key and
turn the ignition On the Security light comes on and
then goes off. If the Security light stays on the CCM did not
read the proper key pellet resistance. The starter will not crank
the engine.

Take a piece of wire and short pin A to Pin G on the diagnostic
connector above the drivers right knee. That's the top right
pin to the bottom row left pin.

[F|E|D|C|B|A]
[G|H|J|K|L|M]


Turn the key to On.
The Speedometer LCD display will cycle and display any error
codes.Turning the parking lights on will make the display easier to read.

Module 1 CCM
Module 4 ECM
CCM code 51 indicates the key resistance value is out of range.
CCM code 52 indicates the resistance value is less than 50 ohms
CCM code 53 indicates the resistance value is greater than 20K ohms.
(This error usually indicates the wires that go to the ignition key
cylinder are broken).

If you have a ohm meter you could insert the key in the ignition
and unplug the two pin connector at the base of the steering coming
for the ignition key cylinder.

Then measure the resistance at the connector which should
be the value of the key pellet. If not the key pellet contacts
are worn or the ignition key cylinder is bad.

tweetyvette

I'm not real good with a multimeter. I set it at 20k ohm and it measured 2.36 I hope somebody knows what that means cos I sure as heck don't!!!!

tweetyvette

When I insert the key in the ignition with the doors closed the security light stays ON. I will give the info you gave me to the mechanic because its way beyond my abilities, I might break and nail and that would be bad!!!! The pellets are so worn it was difficult to even get a reading on the multimeter they are smooth with the black plastic. I am going to take the key to my Uncle tomorrow who is very good with a multimeter and let him confirm the reading then get back to yall. I'm reallllllly grateful for all the information. Then I will decide how best to proceed, my first inclination is to order the security bypass from Ecklers that circumvents all other VATS problems that could occur in the future, because the old girl ain't getting any younger

Hooked on Vettes

If you place the meter in ohms and short the two leads together
you should read close to zero. When the leads are apart you should
read OL or infinity.

Then touch one of the lead probes to each side of the key pellet
resistor. Don't touch the probe leads with your fingers. If you
read 2.36 your key is probably key #8. Look at the chart I posted.
The value is in the proper range. Example 20K is the same as 20000.
2.36K would be the same as 2360.

Pull the CCM codes and see if any codes are set.

Hooked on Vettes

Since you probably have a nail file, file the plastic down to expose more
of the metal ridge on both sides of the key. Then see if the key works.

tweetyvette

Wow, I was just doing that with my nail drill. I have lots of metal showing, filed the plastic around it and smoothed down. Nothing! Now I'm beginning to think its not the key! Do you think if I disconnected and reconnected the battery it would make a difference? If so I may do that tomorrow, its too late tonight. I'm leaning more toward that Security Bypass from Ecklers more than ever now. Yall have a good night!

Hooked on Vettes

If the key pellet is not read properly there is lock out period of around 4 minutes. If you turn the ignition off and on again during this period the lock out period starts again. Remove the key and wait at least 5 minutes to be on the safe side before retrying. Disconnecting the battery will not defeat the time out.

Have your Uncle replace the ignition key cylinder and fix it the correct way. That will also require a new key #8 cut to match the new key cylinder.

Or tell your Uncle to purchase a variable potentiometer from Radio Shack for $2.99 and adjust it to 2.36K ohms and place that across the two pin connector going to the CCM.
http://www.radioshack.com/product/in...ductId=2062308

cessnaguy1965

This may be a long shot, but I had a similiar experience on my 94 six speed coupe last summer. Turns out, the previous owner had installed an aftermarket alarm which in turn defeated the cranking of the engine. Look all over the car and notice anything unusual or not factory looking on your vette. Siren horns, and most importantly, a hidden switch that deactivates a pile of poop alarm like mine has. In my case, the hidden switch is in the center console near the front. I have to push this switch at the same time I am trying to crank the engine. Hope this helps...

Cessnaguy

tweetyvette

I've had this car for 8 years never ever found any kind of aftermarket alarm looking system. Now I did think of something else, I was in an accident several years ago, (not in this car) but I had the mechanic disengage my SIR on this car. COULD it be possible that has something to do with it????? Its been disengaged for 4 years.

tweetyvette

Ok so I ordered a #8 VATS bypass from Ecklers, thanks for the info Hooked on Vettes . When I get the hush panel off, I couldn't find the two white wires, so then I remembered the car came as an automatic and had been swapped to a 6 speed so I'm thinking they had to change the VATS solenoid thingy. Sure enough when I traced the orange wire from the ignition switch there under several layers of electrical tape were the two wires I need connected to the solenoid thingy. Unplugged it plugged in the bypass and VOILA she cranked. THEN the real problem showed up. It wouldn't idle, it was backfiring, blowing black smoke I was skeeeeered I had blown her up. She was throwing a H41 code, after much reading I decided she needed professional HELP. Luckily I had been told about a guy just up the mountain that had worked on Corvettes exclusively for 15 years. Took her on Sunday and had her back on Thursday purring like a kitten. The OBDI handheld scanner said Cylinder Select Error (limp home mode), come to find out the ecm bracket had broken and my puter was bouncing round all over the place, one of the prongs on the eprom had gotten bent in the process, he took it apart cleaned it up, straightened it up, changed plugs and coil just cos they were BLACK and got me back running. Also told me I have a power brake booster leak. Told him I would worry about brakes later, I just wanted to drive her for a while, it had been over six weeks. I still have a slight hiccup on idle but figure that may be due to the booster vacuum leak. I'm just glad to have her up and running!!!! Thanks for all the suggestions and help.

Kmcoldcars

If you still have only one key get to a local locksmith and get a couple more made NOW. It is much easier and cheaper to do than after you lose your only key.

ghoastrider1

I heard somewhere.. ACE Hardware is now doing those keys for lots less than many locksmith folks and a whole lot cheaper than the dealer. Best of luck.

lt4obsesses

Might want to get those brakes done sooner than later, because, well...they're kind of important. Especially to the folks in front of you.