QuestionQUESTION: Hello, i have a 98 Concorde, the car was born with the 2.7 that threw a rod at 49000, we bought the car from a used car dealer that informed us that the engine was a 3.5 out of a 300m, possibly a year newer.. we were told the car would not run with the 3.5 computer, so the 2.7 computer remained.. The car ran for 30, 000 miles like this, then the guages started intermittently working, but the car always ran great, one day the car would not fire, techs have not been able to hook car up because engine does not match vin, the only code that reads is no connectione between computer, a chrysler dealership told me the computer was bad, so i sent the original computer off for one that was supposedly programmed for the car, obviously i was swindled, because the computer I got was eguipped with security where mine wasnt.. So now i need to get a computer for the car.. I was told also that it was not possible for a 2.7 computer to fit a 3.5 as the harness plugs are physically diff, is this true?? I need to buy a computer for this car, but dont know what to get, and neither does the dealership, please advise if u can think of anything, thank you..
ANSWER: Again, send me the last 9 digits of the Vehicle Identification Number and I'll see what I can come up with.
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QUESTION: HI, the VIN is for the 2.7 equipped car, which now has a ho 3.5.. but the last 9 are 6wh208624... I was told by dealer I got car from that the car used the 2.7 computer, even after the 3.5 swap.. I have also been told the plugs are diff and that the harnesses would have had to been changed, i see no evidence of this, Im not an expert, nor a professional mechanic, but i grew up under cars and around em, any advice would be awesome!!
ANSWER: Unfortunately I can't give you a real clear cut answer on this one. Changing out a 2.7 for a 3.5 is not something I personally would have done due to the problems that have manifested themselves in your case. My first concern is that theoretically a 2.7 ECM doesn't have the hardware or software in it to run a 3.5 engine, so I doubt the computer was the one that the car was born with, so to say. The computer that was used could have been from a 98 with a 3.2 or maybe a 99 with a 3.5 either may have worked since they use the same sensor packages and will have the same wiring harness connectors. The only real difference would be the preprogrammed injector pulse width logic and possibly a minor difference between O2 sensor calibrations. Your best bet would be to scavenge around in a junk yard to try and find a computer from a 99 3.5 LH body car that, obviously is not equipped with a factory security system. Good luck, you'll probably need it.
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QUESTION: Howdy again, i found a 99 LHS that has an HO 3.5, they were unsure if the car had a security system or not.. They told me i coukld try it and if it did not work to bring it back.. I unplugged the ECM that was in the car and plugged in the one i brugh home.. The car will fire on a single cylinder, but no more than that, and it will only fire once immediately following turning the key enough to engage the starter.. Does the security system cut the power to the fuel pump?? or if the ecm had security would the car not roll over.. And if it has security, can i disable it , or would it be better to take computer back and search for one that I know does not have security!! thanx for the help so far, I feel i am closer, it was nice to hear it fire at least a couple o times..
AnswerThe computer that you just installed would appear to have the security system enabled. Unfortunatly there is no way to disable it. The security system disables the engine by shutting off the driver circuits in the ECM for the fuel and ignition systems. All you can do at this point is keep looking for a compatible ECM.
