[AMC-list] Pin in Pin out and WAIT a minute! OBD2 requires re-flash

[Jesse <j2sax@xxxxxxxxx>]

Wow, leaving for vacation and no time for detials, however, on a pin test. you need a breakdown of what pins on the vehicle side of the ECM connector go to what and what the voltages are supposed to be and, in some cases, what conditions change the voltage.  

You will first find the ground pin and check it to make sure you have a good ground circuit to the ecm.  Then you will use that ground to CAREFULLY measure the voltage at each pin and compare it with the required amount.  Make sure your voltmeter is set to the proper range and make SURE you do not cross pins.  There has to be a club or forum somewhere that can supply you with the specifics for your vehicle...HOWEVER, BEFORE YOU DO ANYTHING ELSE.....

You mentioned this was a 1996 and that you put in a junkyard ECM... did you have the ECM flash re-programmed to your specific vehicle?  If not that is the source of all your problems.  All 96 and up Domestic vehicles have a Flash RAM Module that controls the ECM.  It USED to be that there was a removeable, hard-coded chip (PROM) but hte new vehicles have a RAM chip which accepts new software just llike a USB drive or digital camera with an SD card.  

Chryslers actually have a 2-3 step process for reprogramming.  If either your vehicle or the one you got the ECM fromm had a anti-theft system there are procedures taht have to be followed.  In addition to that and the OE calibration software upload, in Chryslers you also have a separate step to "upload the VIN, mileage and Pinion factor".  

Very few aftermarket shops have the capbilities to do this as it requires specific hardware that allows communication through the ALDL port (diagnositic plug under your dash) to the OE website that allows the upload.  (Either a factory diagnostic tool or a properly equipped PC with a pass through device will work.)  

In most cases you have to go to a dealership to get it done, but check around to see if someone in the aftermarket can do it more inexpensively.  

Do NOT let someone offer to program it "off the vehicle" as this rarely works on Chryslers and NEVER with one that has antitheft

do NOT let some guy with a Snap On "Brick" tell you he can do it.  The only thing he will be able to do is upload the VIN/Mileage/Pinion factor.  The ECM calibration file can ONLY be done with a Flash Reprogramming device.  

Finally, make sure that they check for "relearn procedures".  In some vehicles, when you introduce a new ECM into the engine management enviroment, the inputs and controlled devices will not "play nice" until they are properly introduced to the ECM, which requires a specific procedure to be done, even after the Flash.  Any dealership will know this, if it is required.  

Gotta run, good luck!  

Jesse


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