Question about 2003 Cadillac CTS
Trying to replace the ecm on a 2003 cadillac cts
Unblot it , unplug it and replace . then take it to the dealer so they can remarry all the other modules to the pcm .
Posted on Dec 16, 2014
I was reading through the replacement procedure for the ecm in your vehicle.Here`s what I found.you may use a used ecm but it does have to be reprogrammed to your vehicle and it can only be done at the dealership.This I know because I worked at a Cadillac and G.M. dealership.I worked at a dealership for 16 yrs.The other thing is you don`t` need the vehicles vin that the used computer came from.The only one you need is your vin number.This number has all the information that your car is equipt with.The used ecm will have the other vehicles fuel continue password so the programming will put in the fuel continue from your vehicle.The other thing that needs to be programmed is the engine oil life and the transmission oil life or they revert to 100%.Then an idle relearn procedure will have to be performed.The only thing any other shop can do is get the codes or clear the codes.But they can not program a computer.Only the authorized dealerships have this software.Hope this helps clear up your any questions.Good luck.
Posted on Dec 22, 2009
Testimonial: "Thanks for all your time and knowlege!"
I have the same problem. The dealer has installed a new throtttle body, then a new ECM. I STILL have the same problem. The dealer has no ideas and now wants to charge me to see if my valve seals are leaking. Sure, after $2,400 I'm going to let you pull the top of the engine off to check my valve seals.
One mechanic (non-Cadillac) feels the battery ground wire is corroded and should be replaced so that's my next step.
Posted on May 25, 2011
The PCM is indicated in the diagram (#1)
Posted on Oct 08, 2011
If it is in the fuse box it should be labeled PCM. If it isn't there it may be in a wiring harness under the hood.
Posted on Oct 14, 2012
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