I have a 99 chevy blazer that just turned 200,000 (proud of her) I have had some goofy problems with my ignition. The security sensor activates itself sometimes when I start up my carwhich disables the injectors so my car shuts right back off. I have to go through the ordinary ten minute wait until it resets. Sometimes this takes 3 periods to finally reset and fire up normally. A friend had the same problem and he went ahead and replaced the tumbler and also the security sensor down on the colum. But with mine when I go to start it sometimes it takes a little playing with the key because i cant get ithe key to turn over in the tumbler. But after messing with it I can get it to turn over after a few seconds. Should I go ahead and replaced lock and tumber and also go ahead and do the security sensor or do you think it may only be the lock and tumbler? Any tips on doing this? Please help I appreciate it.

 

Sounds like the key is pretty worn from years of use. This could be the cause of all of your troubles. The passlock system reads the key as it is inserted across the tumblers. If the key is excessively worn, it is likely that the passlock system would see it as an invalid key.

Do you have another key that has seen less use? If so, do you have the same problems with this key as well? The dealership should be able to cut you a new key based off of your VIN. I do not think it is exactly cheap, but its an option.

Just a note, if you change out the ignition cylinder, the key for the door will be different than the key for the ignition.

 

The security light coming on and setting the Passlock system off usually indicates a failing ignition switch, which runs about $60. Fixes the problem.

You however, since you say you sometimes have to finagle the key in the cylinder...I would think that you might actually have a perfectly fine ignition switch, and that either your key, or your ignition cylinder (tumbler) is bad. Both the ign. switch and the ign. cylinder run about $60. You should get a new key with the cylinder though...if so, that would be optimal, as I'm sure 200k miles of starts can result in a pretty well worn key!

 

I agree with both of you. I was planning on putting a new lock and tumbler in and seeing what effect that has on the problem. Am I correct to believe that if I get a new lock and tumbler with a second key that the computer will program the cylinder to the new key with three ten minute periods with the ignition simply in the on position? As apposed to buying a tumbler and fitting it to the exsiting key. How involved is it replacing the tumber? I have done it in older cars but not with a newer car involving all the electronics.

 

would it mean anything if my security light on the dash stays lit the entire time while driving and starting back up.. Sometimes it flashes which I would assume means its activated because it shuts the injectors off while starting it up.. After its started I have no problems while its running. Just curious if it is a worn key if that would also keep the security light lit.

 

A continuous showing security light means the passlock system has a problem (be it from the ign. switch, key, module, etc). Flashing means the key is bad...or is tripping the system at least.

 

Yeah sometimes it trips the security feature sometimes it just has it let and starts up fine. So from what everyone seems to be telling me is first to replace the tumbler which comes with a new key. If thats not it then replace the ignition switch then after that the module? If i replace the tumbler and new key the cylinder will program itself to the new key cut correct, with the 3 repeated resets of 10 min ?

 

Check in the DIY section for the Passlock programming procedure. That'll run you through it.

As I said, a worn out key can cause the passlock system to lockout the fuel. If you have to wait 3 times for it to start, then the security light will stay lit for that entire key cycle to tell you that there is a problem with the system. In this case, the problem is most logically the key being worn out.

As I asked earlier, do you have a less worn key? If not, maybe the easiest thing to do is to ask the dealer how much it would cost to have a new key made based off your VIN.

 

Yeah i have another key dont think that makes much of a change though the light remains on... I may call the dealer just to see how much they are if not that choice i may just start with replacing the tumbler then probably the ignition switch

 

Try the passlock relearn procedure with the better key if it is in better condition.