Have an 89 IROC - z and i've come to the conclusion i need a new ECM by doing some testing. anyways, how do i replace it with a new one? do i need to get it programemd by a chevrolet repair shop or do i take out something in the current one and put it in a new one?

Oh and its a 89 iroc with 5.7L, but it was converted to a 5speed,dont know if that matters.

 

If you get 1 from auto parts store it will not have the prom in it. You take yours out and put it in new ecm.

 

Your biggest problem with the ECM is the Prom (chip) if you did not update it when you changed to a 5-sp. The stock factory chip is not working with the changes you made.

 

The car was originally with a auto 4speed so if i pull out this ecm and put in a new ecm for this car, all do i swap out the prom? is there another chip or just the prom? and the cover holding the prom chip is bolted onto the ecm and also glued so im wondering if when light hits the chip it will erase the memory?

 

the chip difference between the 5 speed and auto is only in the fuel mapping, idle settings, and maybe spark curve. but yes, just pull the chip from the old one and put it in the new one. its under the kick panel on the passenger side

 

Alright thanks guys!