Jeep Repair: 1997 Jeep Grand Cherokee Laredo, jeep grand cherokee laredo, jeep grand cherokee

Question
QUESTION: Hi there my 1997 Jeep GC Laredo was making alot of noise wia the alternator, and was having problems starting I therefore put a new alternator in (fixed the howling belt problem) and changed the battery.  Once both of those were replaced the jeep would not hold a charge.  Would start great with a boost and run but as soon as the cables were removed it would die.  I was then told that the voltage regulator was not working (check guages light was on and battery guage was not registering) and as it was in the ecm I needed to replace it.  I purchased a used ecm, installed it and now the jeep will start up no problem and the battery will hold a charge but the gas is cutting out after 3 or 4 seconds of starting, even when holding the gas pedal down it just shuts off and won't stay running??? Any suggestions help would be greatly appreciated, I am trying to avoid the high price at the mechanic's if possible. Thanks

ANSWER: u either A put a PCM from a jeep that had an alarm  or B u triggered the alarm U have yourself.
If u dont have an alarm system on your jeep then u will need to get a different PCM because its burnt into the PCM u got and will never go away.

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QUESTION: Thanks for your fast response,  I truly wish I lived in Atlanta to just come and see you but I'm in Canada ;), does the PCM have to be the exact same model number as mine or are they interchangeable and does the PCM have to be programmed? Thanks again ;)

Answer
a used PCM  is that a used PCM  the vin and all the setting are burnt into them and can not be changed. Go to this site I have used a few times  and the vin and everything for your jeep is already programed into it.
http://www.autocomputerexchange.com/