If information is what you're after, you got it *free* here, yet you are still not satisfied. Yes, somewhere along the line you'll have to pay for something. Facts: 1. You need a new key. 2. It must be cut. 3. It must be programmed to your vehicle. Options: 1. If you have 2 working keys, you can program a new one yourself. You buy the key, have it cut & program it yourself using instructions in your owner's manual. Your missing key will still start your car. 2. Buy the key and have it cut. Take your new key and all old keys to dealer or somebody with a DRBIII. They can delete all keys from memory and program the ones you have, along with the new one. Only the keys in your possession will start your car. 3. Buy a blank key, a DRBIII, and the required key cutting tools. Have at it!
Full-Quoter bullshit wrote: I'm not sure about that. Is it a given that keys with Sentry-Key feature that keys need to be uniquely cut for each car? Perhaps all keys for cars of a given make, model and year with Sentry Key are physically the same? I still say that it's the vehicle that gets programmed for the key - not the other way around.
Why haven't you replied to my previous post about rolling-codes applying only to the key fob and not the key itself? Can you explain how an rf-energized key can power a micro-controller to generate the rolling code without a battery, and save the last code it used? Why would a key need to impliment rolling-code, given that the code stored in the key can't be sniffed over the air like the keyfob can?
Not sure a new key needs to be cut? How do you propose they turn the ignition cylinder with a key that hasn't been cut to match the cylinder? SKIM has nothing to do with how the key is cut. You can take all the tumblers out of the ign cylinder so any key will turn it, but SKIM will still do what SKIM does.... It won't let the vehicle run if the key hasn't been programmed to the vehicle. What you "still say" doesn't mean jack shit if it's wrong. You asked how it works and I told you. Believe it or don't. I really don't care. A key can only be programmed to one vehicle. Period!
Why haven't you replied to my previous post about rolling-codes applying only to the key fob and not the key itself? Can you explain how an rf-energized key can power a micro-controller to generate the rolling code without a battery, and save the last code it used? Why would a key need to impliment rolling-code, given that the code stored in the key can't be sniffed over the air like the keyfob can?[/QUOTE] My service information states that the rolling code is between the SKREEM and the PCM on the PCI bus. The SKREEM reads the RFI chip in the SKIM key, the SKREEM also has a secret code programmed in it that the SKIM key has to recognize to enable a valid start sequence. Thusly, when a new key is procured, it has to be cut to match the tumblers in the lock cylinder, it has to be programmed to recognize the secret code in the SKREEM and the SKREEM has to be programmed to recognize the new SKIM key. Odds are I'm right since I've successfully programmed a number of new SKIM keys to replace lost keys on late model ChryCo vehicles and have watched the progression of the process on my DRB3.
http://www.afs-securitysystems.com/Transponder-Key.php ---------------------- There are currently three types of vehicle transponder system: Fixed Electronic Code Each key has a different electronic code written to it. These codes are permanent, they are not altered when the engine is started. Rolling Electronic Code Each key has a different electronic code, which is re-written each time the engine is started. Only the immobilizer manufacturer knows the procedure by which the code is changed. Cryptographic Electronic Code The transponder memory is protected using bi-directional encryption of data. Internal algorithms are configured to interpret the messages sent from transponder to ECU. This is similar to password protection. Keys can be Cut to Code, Keys made to Locks, Locks made to suit your key, Transponder keys copied,Crypto keys programmed,and Remote Key Fobs supplied and coded. ---------------------- Ok, so which type of system has Chrysler used, and on which car line? I still say that: 1) for a fixed code key, the key could be used to start any number of cars if the key fits the ignition and if the key was programmed into the car's computer beforehand. 2) even in the rolling-code situation, as in the keyfob situation, a floater key could be used between 2 cars because rolling codes use code-jumping or code lookup as a backup for bad reads. For example, if I press the lock/unlock button on my key fob a dozen times but I'm out of range of my car, when I'm in range and press the buttons the car will get a code that it's not expecting, but it will be a code that it would have expected in the future. Same would happen for a key transponder. 3) the need for a rolling code or crypto-code keys is not clear, except for very expensive cars. See also: http://www.wired.com/wired/archive/14.08/carkey_pr.html No explanation given in that article how any transpoder system was circumvented except through the use of key-substitution, or hooking in a jury-rigged ignition computer, or a back-door hand-brake pumping sequence (as in the Honda). And Glenn, you still haven't explained what these are for: http://www.bypasskit.com/categories.aspx?catid=14
That doesn't sound like rolling code. That sounds more like this: ------------------- Cryptographic Electronic Code The transponder memory is protected using bi-directional encryption of data. Internal algorithms are configured to interpret the messages sent from transponder to ECU. This is similar to password protection. ------------------ For both fixed and rolling code key systems, the key does not recieve any signal from the car's computer. It only transmits a code. It's a uni-directional system (key -> car). In theory, both a fixed key and rolling code key could be used on 2 different cars (naturally with exactly the same physical key-cut). With cryptographic keys, there is bi-directional data transfer (key <-> car) and this would allow a key to be coded to a specific car. Which chrysler vehicles have this Cryptographic code system?
That doesn't sound like rolling code.[/QUOTE] What (of my 2 above paragraphs) doesn't sound like rolling code? You should ask at that web site that you're considering to be a better authority on the subject than Chrysler.
The fact that there *may be* "rolling code" between the SKREEM and the PCM is irrelavent (and a curiosity). It's the communication between the Key and the SKREEM that we're talking about. Read this: ----------------- OPERATION Each Sentry Key has a unique transponder identification code permanently programmed into it by the manufacturer. Likewise, the Sentry Key Remote Entry Module (SKREEM) has a unique "Secret Key" code programmed into it by the manufacturer as well. When a Sentry Key is programmed into the memory of the SKREEM, the SKREEM stores the transponder identification code from the Sentry Key, and the Sentry Key learns the "Secret Key" code from the SKREEM. Once the Sentry Key learns the "Secret Key" code of the SKREEM, it is also permanently programmed into the transponder's memory. Therefore, blank keys for the Sentry Key Remote Entry System (SKREES) must be programmed by the SKREEM in addition to being cut to match the mechanical coding of the ignition lock cylinder. Refer to Electrical, Vehicle Theft Security, Transponder Key, Standard Procedure - Transponder Programming. The Sentry Key's transponder is within the range of the SKREEM's transceiver antenna ring when it is inserted into the ignition lock cylinder. When the ignition switch is turned to the ON position, the SKREEM communicates with the Sentry Key via a radio frequency (RF) signal. The SKREEM determines if a valid key is present based on the information it receives from the Sentry Key. If a valid key is detected, that fact is communicated to the PCM via the PCI bus and the vehicle is allowed to continue running. If an invalid key is received by the PCM or no status at all is communicated, the vehicle will stall after two (2) seconds of running. The indicator light will be flashing at this point. The Sentry Key's transponder can not be repaired. If it is faulty or damaged, it must be replaced. ----------------- -> The SKREEM has a unique code which is sent to the key -> The key must initially learn the SKREEM's code. No idea if a key can learn more than 1 SKREEM code. -> The key has it's own code, which the SKREEM must initially learn. -> In use, the SKREEM and KEY exchange codes. Seems that the SKREEM transmits it's code first. No idea why the key needs to know the SKREEM's code. I don't know what situation the designers were imagining such that they wanted the key to respond to a code transmitted by the SKREEM. Rolling code implies that the code numbers are not static, but that they change based on an algorythm known to the receiver. All the descriptions of bi-directional code transfers I've read so far between keys and SKREEM modules use static codes - not rolling codes. And my question still stands: What make and model year vehicles have transmit-only key transponders, and which have bi-directional key transponders?
"NotMe" |I have an 04 Mini Van with wireless locks and electric doors. I need to | replace one of the keys and am getting all sorts of confusing info and | prices. | | Where can I find reasonable prices and reliable equipment. One vendor will | sell me OEM keys but I have to take to someone to have them programmed. | Others will sell me the keys for one price and the instructions for | programming for another. | Problem solved!!! Seem a good friend of my one of my grand kids is dating the kid of someone with connections @ Chrysler. Key was replaced with an OEM for ~$15 plus tax which is a h*ll of alot better then the $175 to $185+ I've been getting Thanks for all the input.
