Can't read stock tune out of LLY ECM

[JoshH]

Every time I try to read the tune out of the truck, I get an error message that says "EFILive Interface not detected. Cannot communicate with Flashscan or Autocal." or something to that effect. The scan tool connects and displays data just fine, and it will read the tune out of my LBZ with no problems. Anyone have any ideas?

[minytrker]

Do you have after market radio or alarm? I have had to pull the fuse for the radio on a couple LLY's with aftermarket radio's.

[JoshH]

Stock radio, no aftermarket alarm. The only non-factory stuff is flexalite electric fans and a Suncoast 6 speed conversion.

[JoshH]

Anyone? I could really use some ideas/suggestions here.

[GMC-2002-Dmax]

LLY's can be difficult, close all doors, shut the dome light off, shut down the radio, HVAC, etc. have the cable to the truck OBD port-Flashscan-computer before you key it on.

Key it on and wait 20 seconds for all the modules to boot up and the dinging to stop.

I flashed one yesterday in the truck and when I went to read the file out it said the ecm was locked.

I had to key the truck off for/on 5 times before it said it wasn't locked.

I normally bench flash all ecms and they are never a problem on the bench, some trucks are funny about flashing in the truck.

I would suspect low voltage in the trucks batteries ????

[JoshH]

Thanks Tony. I'll give all that a try and hook up a battery charger.

[JoshH]

Well, I did a little digging and found that the truck does have an aftermarket alarm on it even though it doesn't use an aftermarket key fob. Once I disconnected all the wires they tapped into the ignition switch to power it up, I was able to read the tune out. Thanks for the suggestions from both of you guys.